Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, 850 California Police Brakes
Parts, supplies & service
Table of contents
- Brake actuation rod (for the rear brake)
- Brake adjustment
- Brake cable replacement information
- Brake cable-to-lever angle
- Brake lever length (on rear brake plate)
- Brake light switch alternative 1 (front)
- Brake light switch alternative 2 (front)
- Brake light switch repair (rear)
- Brake light switch replacement (rear)
- Brake line replacement information
- Brakes - External brake return spring
- Brakes - Turning brake drums - 4 leading shoe brakes
- Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing
- Disc brake - adding a second disc
- Disc brake axle
- Disc brake caliper
- Disc brake fender
- Disc brake fender stays
- Disc brake floating rotors
- Disc brake forks
- Disc brake fork shroud / headlight ears
- Disc brake hub flange / bearing carrier / disc carrier (disc side)
- Disc brake hub flange / bearing carrier / disc carrier (non-disc side)
- Disc brake installation on a non-disc brake loop
- Disc brake - installing FAC dampers into original disc brake forks
- Disc brake line bolt size
- Disc brake master cylinder
- Disc brake master cylinder rebuild
- Disc brake master cylinder size
- Disc brake rear
- Disc brake rotor
- Disc brake spacer between bearing and fork leg
- Disc brake spacer between wheel bearings
- Disc brake spacer for hub flange / bearing carrier / disc carrier
- Disc brake top nut and tube sleeve
Brake actuation rod (for the rear brake)
Updated: 2009 Mar 16
In early February of 2009, Joe Cox contacted me asking about the brake actuation rod. I sent him some measurements and photos of my original, and then he crafted one.
Gregory Bender's notes
The brake actuation rod connects the brake pivot to the brake actuation arm on the brake plate. It is made of 6 mm rod, bent at 90° at one end (to fit through the brake pivot) and threaded at the other end (6 mm × 1 mm) to accept the adjustment nut.
I'd use 6 mm Stainless Steel rod. A bit more difficult to bend and thread, but it can be polished and will never rust. McMaster-Carr sells it; search for item number 1274T15.
If you don't have the nut, this one from McMaster-Carr would work: 90368A300. Just bevel the bottom and have it push up against a short length of cross drilled rod of larger diameter.
Key measurements:
- Length from inside corner of the bend to the end of the threads: 455 mm
- Length of bent end from the inside corner of the bend: 10 mm
- Approximate Length of threads: 50 mm - 60 mm
- The short little cross-rod that the knurled nut runs up against is made of 12 mm diameter rod. Instead of buying a entire length of rod, I'd just buy a 12mm bolt that wasn't fully threaded and make it out of that.
I'd drill a hole for the cotter pin, stick 10 mm in the vice and bend it 90°. Measure 455 mm to the end and cut it off. Thread the end to 50 mm (or so) and call it good.
A couple of notes:
- Use a washer between the cotter pin and the pivot arm to prevent wear and breakage of the cotter pin.
- If you look at the photos carefully, you'll notice the original design had corresponding “V” notches cut/filed into the knurled adjustment nut and the corresponding very short cross rod. This “V” notch is nothing more than a locking mechanism to prevent the nut from coming loose, etc. Be sure to add one of your own.
Brake actuation rod for the Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
90° bend at the forward end of the rod (I'm in the middle of experimenting to get more feel with my Moto Guzzi 850 T brake drum).
Photo courtesy of Gregory Bender.
Brake actuation rod for the Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Cross rod and adjustment nut (Moto Guzzi 850 T brake drum shown).
Photo courtesy of Gregory Bender.
Brake actuation rod for the Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Cross rod and adjustment nut (Moto Guzzi 850 T brake drum shown).
Photo courtesy of Gregory Bender.
Brake actuation rod for the Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Cross rod and adjustment nut (Moto Guzzi 850 T brake drum shown).
Photo courtesy of Gregory Bender.
Joe Cox's notes
Overall the fabrication of the brake rod was easy. There are a few things that should be noted:
- All of the parts ordered from McMaster-Carr were perfect and they arrived within 24 hours - I was impressed!
- I recommend that you cut the rod you get from McMaster-Carr into two equal sections before you start the project
- It's a long rod and a shorter rod is easier to work with.
- Plus it's nice to have a second “blank” just in case you screw the first one up (like I did)
- Before you start to thread the rod, bend the end that goes through the brake lever first
- To bend the stainless steel rod - you must apply heat to the area that you plan to bend. I used a little propane torch to do this.
- I recommend that you taper the tip of the rod a little, before you apply the threading tool (dye)
- I used my bench grinder to taper the end a little.
- I also recommend that you apply a little bit of grease to part of the rod you plan to thread. This will ensure “good deep threads” are created.
- Rather than use a “bolt” for the “cross rod” - I found a short Clevis Pin at Ace Hardware that worked great.
It's a very nice setup and should work fine for years!
Brake adjustment
Updated: 2010 Jan 28
I extracted this information from Greg Field, Bruce Giller, and Paul Linn on the Yahoo! Loopframe_Guzzi news group.
Drum brake adjustment with wheel still on bike
by Paul Linn
- Disconnect cable and tie rod.
- Move one lever so that shoe just barely comes into contact with drum surface. (Check this by spinning wheel and listening for the tell tale scrape of the shoes on the drum surface)
- Mark this position with an upright mark on splined part only.
- Repeat step 3 for other lever.
- Place levers on splined parts so that the tops of the levers are now lined up with the marks made in step 3.
- Rotate front lever to its upright position and connect tie rod.
- Rotate rear lever to its upright position and check length of tie rod. If it,s to short or to long, adjust tie rod now so it can connect to the rear lever.
- You will have to fine tune the tie rod so that both shoes contact the drum at the same time.
- Connect cable, adjust free play and test brake action.
This same procedure can be used for the rear drum also. Your drum brakes will now be just a good as a disc setup. After following this simple adjustment procedure you will no longer have that mushy feeling most people find with the front brake switch style cable and you will be able to STOP on a dime.
Synchronizing four leading shoe brakes
by Greg Field
- Center the hub by spinning the wheel and locking the brake and retightening the axle bolts.
- Get all linkages to “optimum” position. This means that when the shoes contact the drum, the actuating arm and pull rod are as near a right angle as possible, for best mechanical transfer of force. Rotate the actuating arms on the shaft until this is so.
- Pull off the right cable
- Remove the pin for the back shoe on the left side.
- Adjust slack out of the left brake cable until there is significant brake drag (light scraping is not enough).
- Manually actuate the rear shoe until the brake drag doubles. Then, adjust the link rod until the pin can be re-inserted. Fine-tune adjustment if necessary to keep drag equal between the two shoes. Hopefully, the angle between rod and arm will still be near 90°.
- Slacken left cable till all brake drag goes away.
- Repeat steps 3 through 6 for right side.
- Then adjust slack out of left cable till brake drag from the left side doubles what was already there from the right.
- Adjust out slack at the hand lever, which preserves left-right synchronization.
- Then, for gnat's-ass perfection, re-center the hub, and fine-tune the left-right adjustment.
When done thusly, most folks I've done this for want them de-adjusted so they're not so grabby and sudden, but this is the place to start because if your shoes aren't 100 percent perfect, this will make them the best they can be.
Here are the Steps to a Great Front Brake
by Bruce Giller
- get new shoes with modern material. If your shoes are original, recycle them at a brake recliner or put them on the wall as Guzzi Art. Mark Etheridge of Moto Guzzi Classics sells them
- arc the shoes to the drum. (see instructions below)
- adjust the front brakes so that both leading shoes contact the drum at the same time (see instructions below)
- as the shoes wear, re-position the front drum's brake levers to compensate. Adjusting the brake cable is useful over a short range - plus the cable itself tends to lengthen. (I'm still writing this one up…it is Paul Linn's tip)
For those who want to do arc the brake shoes to the drum:
- Obtain some 80 grit sandpaper with a sticky back (you can find strips of sandpaper at your local auto paint store)
- Line the inside of the brake drum with one layer of the sandpaper (you will have to cut the paper to the width of the drum)
- Pencil on hatch marks over the entire width and length of each shoe
- Assemble wheel back on the bike.
- To center the wheel, use the front brake lever several times while spinning the front tire, then hold the brake lever down while tightening the front wheel nut
- Spin wheel and apply brakes a few times to sand down shoes
- Remove wheel and inspect pencil marks. If some of the marks are still there, repeat Steps 3-6 until the pencil marks have completely disappeared
- Remove paper from the drum and clean out the drum. This procedure will leave a pile of shoe particles inside the drum, especially if the shoes are new
You want to make sure that the two leading shoes are contacting the drum at the same time when braking. The procedure works better if you have 3 arms but can be done by one person.
- make sure that your front wheel is centered on the axle. To center the wheel, use the front brake lever several times while spinning the front tire, then hold the brake lever down while tightening the front axle nut
- Disconnect the metal rod connecting the two splined levers for each shoe from the front lever. It has “forked” end pieces which are held in place by a small pin with a cotter pin. The rod is welded to one end and screwed into the other.
- Squeeze the brake lever to where the point where the front shoe is contacting the drum
- At the same time, manually make the rear shoe contacts the drum by pulling back on the rear brake shoe splined lever
- Adjust the length of the connecting rod for a tight fit between the two shoes. You probably won't get a perfect fit due to the large adjustment distance. You have to turn the forked end 180 for each adjustment. I made mine a bit tight to compensate for future shoe wear
- Test the action of the front shoes. Put the cotter pin back in the front lever's pin. Now when you pull on the front brake lever, the two shoes will contact at the same time.
Brake cable replacement information
Updated: 2008 May 12
What is so great about the Barnett front brake cables? In my opinion, several characteristics make them the best choice available today.
- The cable is thick.
- The individual strands are thin and numerous.
- The individual strands are wound in a more longitudinal direction along the length of the cable…rather than more cross-wise.
- The cable liner allows the cable to move smoothly.
- The barrel ends of the cable are separate from the cable ends…allowing the cable to rotate within the barrel end. This reduces the stress on the cable and extends the life of the cable.
- There is no brake switch! In my opinion, this is critical to getting adequate braking performance. No matter how good a person sets up a front brake, the presence of a brake switch in-line with the cable will always deteriorate braking performance at least a little bit. In my experience, the presence of a brake switch is a major contributor to poor braking performance.
- All this adds up to less stretch and more pull being transmitted to the front brake. In my experience, it makes a big, meaningful improvement.
Charlie Mullendore of Antietam Classic Cycle worked closely with Barnett to get a replacement brake cable made for his two-leading shoe front brake with civilian bars.
Please Note! Charlie Mullendore does not sell Barnett cables. Please contact Barnett directly.
Here is the information from Barnett and Charlie:
Barnett wrote:
Charlie,
Most of the time we keep prints of the cables on file for future reference or it goes into a temporary file. If we have the information on the bike model so we know what the cable fits, we usually save it. We should still have the prints for your cables and I will make sure that we save it. It's never a bad idea to send the cable(s) just to make sure that the new ones are correct. If you can, let me know what the year and model of Moto Guzzi it was and I will have Joe attach it to the print for future reference. If you or any of your friends ever have a question about a cable, call us at 805-642-9435 and ask for Joe. If Joe isn't available, ask for Mark. They both work directly with the cable dept.
Chris Taylor
Barnett Tool & Eng.Charlie writes:
I've sent all the information from the invoice and what models the same cable will fit. They've been a real pleasure to work with, prompt responses to my emails, great product, finished when they said it would be. I'll measure my old cable soon and post the dimensions if still needed also. Cheers
Charlie
Brake cable-to-lever angle
Updated: 2010 Jan 28
I extracted this recommendation from Ralf Brinkmann off of the Yahoo! Loopframe_Guzzi news group. In Ralf's own words:
I found an interesting photo of a 2 LS front brake - sorry for recycling it for my drawing.
My theory in short words:
- The ideal angle between brake lever and the pulled brake cable is 90°. The more this angle differs from 90° the shorter the resulting length of the brake lever will be and so the resulting torque.
I assume less than 60° for the angle in the picture when the brake is pulled. The effective length of the lever arm in the example results in less then 86 percent of the real length approximately.
Moto Guzzi drum brake cable to lever relationship. Effective lever length = real lever length × sin(angle).
Photo courtesy of Ralf Brinkmann.
- The eyes in the connecting rod should have nearly the same distance from center to center as the cam shafts of a 2 LS or 4 LS brake.
Brake lever length (on rear brake plate)
Updated: 2008 Dec 20
There are two different splined brake levers that are secured directly to the rear brake plate.
- One style is open on the non-splined end and measures approximately 70 mm from the center of the splines to the center of the pin. This is the most common lever.
- Another style is closed on both ends and measures approximately 100 mm from the center of the splines to the center of the pin. This is less common and was fitted to many police models. Thanks to Cam Conklin for posting the length of his lever on the Yahoo! Loopframe_Guzzi news group.
Brake light switch alternative 1 (front)
Updated: 2008 Dec 22
I extracted this information from Bill Dudley on the Yahoo! Loopframe_Guzzi news group. In Bill's own words:
I recently got pissed off at the cable switch, and decide to do what I've also done to other bikes (a Honda CB400F, for example, when it's hydraulic front brake switch packed up).
I rigged up a way to mount a microswitch such that it is activated by the front brake lever. Just the slightest movement of the front brake lever will move the microswitch lever enough to light the brake, so it's now easy to flash the rear brake light at tailgaters (not that it does all that much good).
Since my Ambassador doesn't have the stock choke lever, I have the “similar, but different” one sold by MG Cycle, part LAM8405. This choke lever required that I make a spacer to raise it up about 1⁄4 in, and also to rotate it's anti-rotation tit about 15°. So I made a sheet metal “L” bracket that fits between the choke lever and my 1⁄4 in spacer, and the microswitch is bolted to that. Then I needed a little “flag” that would actuate the microswitch and also fit between the brake lever and the perch.
I'm not supplying drawings with measurements since you probably won't have the same microswitch I have, or make your spacer the same way, etc., but at least this gives you the general idea.
The brake switch installed. An alternative front brake light switch for drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Photo courtesy of Bill Dudley.
The installed switch showing the spacer under the choke lever. An alternative front brake light switch for drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Photo courtesy of Bill Dudley.
The underside of the bracket, showing microswitch mounting and the flag. An alternative front brake light switch for drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Photo courtesy of Bill Dudley.
A slightly blurry shot of the microswitch and it's “flag” , again, with the choke lever spacer on the right. An alternative front brake light switch for drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Photo courtesy of Bill Dudley.
Brake light switch alternative 2 (front)
Updated: 2008 Dec 22
I extracted this information from Charlie Mullendore of Antietam Classic Cycle off of the Yahoo! Loopframe_Guzzi news group. In Charlie's own words:
Having short-circuited one of my last Barnett switched front brake cables by over lubing (Doh!) and sending the other out as a warranty replacement, I was left with no way of activating the brake light with the hand lever on my ‘71. Last year at one of the WV Guzzi breakfasts, I remembered looking at Rob Prins' Ambo and noticed the Honda (rear) brake switch he had mounted to the fender brace that was actuated by the linkage. Decided I'd try to rig something similar up for myself, if I could find the right switch. I was digging around in a bin marked “Switches” at the shop the other night and found this new-old-stock Bosch unit that looked like it would work. Made a little “C” shaped bracket out of some scrap stainless steel and found some self-tapping stainless screws too.
An alternative front brake light switch for drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.Photo courtesy of Charlie Mullendore, Antietam Classic Cycle.
The switch included a spring and clamp for around a brake rod - both were perfect for my application. Once mounted and the spring slightly tensioned, it functions perfectly. I ran the wires through shrink tubing and zip-tied it to the cable.
An alternative front brake light switch for drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.Photo courtesy of Charlie Mullendore, Antietam Classic Cycle.
An alternative front brake light switch for drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.Photo courtesy of Charlie Mullendore, Antietam Classic Cycle.
Looks a bit “Rube Goldberg” , but does the job.
My friend Joseph tells me the switch is from a ‘60s Sears Allstate (Puch) 250, but I'm not sure how available they are. Did find one place in the UK that lists them: #351 and Domi Racer has two that are similar.
Brake light switch repair (rear)
Updated: 2012 Jan 28
Thanks to Carl Krall for sending me this information via email. In Carl's own words:
No photos, was having too much fun to stop for such stuff, and assumed that when I went inside to look at TOT I'd find out how to do it a much easier way. Already was wearing my soft “kicking-myself” shoes just for the occasion. :^)
If you dig yours out and slide the cover around on the other grommet there's a brass hat on a plunger inside. It spins independently of the plunger rod. Rotate it and there will be a worn place with no more brass, this is probably how most of them die. The positive side (I think) takes the arc and the brass wears down so there's a dead spot, and the terminal on that side starts to look ugly. One could swap wires up top every so often, but then eventually you'd have two dead spots.
So I just repaired over the dead spot with a mess of wires and solder, sorta like conductive bondo, then filed it down. It doesn't matter if it's smooth enough; another fix would be to stick something in the spot so it couldn't rotate toward the contactor, or leave it rough after doing the solder/wire patch. Either way forces it to contact a new unworn area and not to settle into the depression caused by the wear.
Brake light switch replacement (rear)
Updated: 2011 Aug 29
CEV replica
The common replacement for the original CEV brake light switch is a plastic bodied piece with a brass plunger. It fits perfectly.
Unlike the original, however, the brass plunger will short the circuit directly to ground through the actuating lever. This blows the fuse and it can be quite difficult to identify the cause of the short. A very poor design.
Photo courtesy of Gregory Bender.
Photo courtesy of Gregory Bender.
Therefore, the brass plunger must be insulated prior to installation. I've found that the cap from a “Bic Ultra Round Stic Grip” pen fits perfectly. With a little dab of silicon, it'll stay in place and function perfectly for years.
Photo courtesy of Gregory Bender.
Lucas replica alternative
I extracted this information from Charlie Mullendore of Antietam Classic Cycle off of the Yahoo! Loopframe_Guzzi news group. In Charlie's own words:
The ‘73 Eldo ( “Al's Eldo” ) that I recently worked on had a rear brake light switch that I couldn't identify. Now I see what it was from: Stop lamp switch for all Norton Commandos, Triumph and BSA triples and Triumph 750 twins. Exact replica of Lucas No. 34815. 05-01059. It mounted up using the stock holes and had spade terminals instead of those aggravating little screw terminals of the o.e. part. At USD $7.50 it's cheaper as well.
Brake line replacement information
Updated: 2006 Jan 12
Tom Christian replaced his stock hydraulic brake lines with stainless steel, black coated Goodridge lines. By doing so, he improved the braking feel and performance while maintaining the stock appearance. Here is the information from Tom:
A couple of weeks ago I installed stainless steel black coated Goodridge brake lines on my disk Eldo and rebuilt my stock 15 mm master cylinder. The improvement is significant, and the appearance remains period correct. The install was trivial, takes at most 1⁄2 hour, with bleeding.
Here is the part ordering info:
- 11315E Goodridge black stainless braided brake hose, 15 in
- 11318E Goodridge black stainless braided brake hose, 18 in
- B59303C Goodridge stainless 20 degree banjo
- B59403C Goodridge stainless 45 Degree Banjo (3)
I'd take at least an inch off of each hose, and go with all 4 banjos at 45° if I had to do it again. The screw-on connectors need to be tight!
Gordon threw in the brass crush washers but I forgot to order new stainless steel banjo bolts - Goodridge's are nice, I've used the stainless steel on our Harley too. The old banjo bolts will work fine, however.
The whole thing was about USD $100.00. Takes less than 1⁄2 hour to install and bleed. Some of the parts come from different locations, so shipping was slower than usual (I usually order Monday and it arrives Thursday like clockwork for the weekend) - this added a couple of days.
When I said “new master cylinder” , I meant I used MG Cycle's rebuild kit and rebuilt my stock 15 mm master cylinder - it was a mess.
Photo courtesy of Tom Christian.
Photo courtesy of Tom Christian.
Photo courtesy of Tom Christian.
Photo courtesy of Tom Christian.
Photo courtesy of Tom Christian.
Photo courtesy of Tom Christian.
Brakes - External brake return spring
Updated: 2008 May 05
Thanks to Frank Granli who sent this information to me in a private communication. In Franks's own words:
I have installed some exposed return springs on my 4 LS front brake, after an idea I saw on your excellent loopframe web page. Somebody had done this with their 2 LS rear brake. Is this something that might be of interest for other loopers? I have done so, because my 4 LS brake had a tendency to almost get stuck in “on” position, the return movement was very slow. This happened even with freshly cleaned and lubricated brake arms. So, before disaster, I have installed these exposed springs, and they do help.
External brake return spring fitted to a 4-leading shoe drum brake as found on some Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.Photo courtesy of Frank Granli.
Brakes - Turning brake drums - 4 leading shoe brakes
Updated: 2008 Jan 15
NOTE: In general, I do not recommend turning the brake drums on these machines. But, occasionally, it may need to be done. I would certainly never perform this as part of any “routine” maintenance.
Thanks to Locky who posted this information on the Yahoo! Loopframe_Guzzi news group. In (mostly) Locky's own words:
…in regards to your question about the specs for the brakes, what I think the brake shop is after is the internal diameter of the drum. I'm not sure about a 2 leader brake but the 4 leader is 219.900 mm - 220.000 mm or 8.657 in - 8.661 in. The brake shoes need to be turned while fitted to the backing plate to 219.880 mm - 219.950 mm or 8.653 in - 8.659 in. But they need to be turned while the cam is in the open position and the cam operating lever at 119.800 mm - 120.000 mm or 4.716 in - 4.724 in from the anchoring lug. That will make sure your break shoes are the same radius as the internal hub when the breaks are applied. The measurement to lock the leaver to is taken from the back of the lever where the cable attaches to the back of the cable anchoring lug. You will have to make something to lock it in this position then have it machined, and that how its done. Hope this helps, Locky.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing
Updated: 2011 Mar 22
Steve Odell used the GuzziTech adapaters to mount the 4 piston Brembo calipers that have a 40 mm mount spacing.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Brembo F08 to 4 piston caliper conversion with 40 mm mount spacing fitment on a Moto Guzzi Eldorado (GuzziTech adapater).
Photo courtesy of Steve Odell.
Disc brake - adding a second disc
Updated: 2012 Apr 05
Thanks to Steve Odell and Charlie Mullendore of Antietam Classic Cycle for providing this information on the Yahoo! Loopframe_Guzzi news group.
Some information from Charlie:
You need either two 39.5 mm thick disc/bearing carriers or a 10 mm thick spacer along with the 29.5 mm one. Joe Kenny did have some on eBay, but I don't see any now. You can email him: jkenny>at>swva.net and enquire about them.
I used 140 mm long bolts on Cam's Eldo when I added the second disc for him, but cut approximately 5 mm off of each as they stuck out too far.
Some additional information from Steve regarding the bolts:
That's exactly what I did with the bolts but I used stainless grade 9 ARP bolts with stainless nylocks and cut them to size.
And a bunch of photos from Steve:
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
A brake disc configuration Steve built with 4 piston 30/34 calipers, and then sold.
Photo courtesy of Steve Odell.
Disc brake axle
Updated: 2011 Jun 23
Thanks to Paul Linn for providing me with some of this information. The axle is part number MG# 13614140.
- Diameter of large portion: 24.9 mm
- Diameter of small portion: 19.93 mm
- Thread size: 16 mm × 2 mm
- Overall length: 291 mm
- Length of larger diameter portion: 92 mm
- Please use these written measurements rather than attempting to read the tape measure as Paul had to hold the tape measure and take the photo at the same time.
Disc brake axle for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake axle for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake axle for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake caliper
Updated: 2011 Mar 15
Disc brake fender
Updated: 2011 Mar 15
Disc brake fender stays
Updated: 2011 Mar 15
Disc brake floating rotors
Updated: 2011 Jul 25
I extracted this information from Mike Tiberio and Charley Cole on the Yahoo! Loopframe_Guzzi news group.
Mike Tiberio:
I got my [EBC] floater from a place called Vintage Brake. They were USD $230.00 each side. They had to order them from England. I only paid USD $15.00 shipping from their US location to my house…part number was MD668LS and MD668RS. LS=left side, RS=right side.
They are listed as being for a Laverda SFC 1000. However they are dimensionally equivalent to the 300 mm rotors fitted to early non-le mans tontis and disk brake eldos.
EBC floating brake disc.Photo courtesy of Mike Tiberio.
EBC floating brake disc.Photo courtesy of Mike Tiberio.
EBC floating brake disc.Photo courtesy of Mike Tiberio.
Charley Cole:
I got the rotors and carriers for my race bike out of England through Vintage Brake as well…also drop shipped. Vintage Brake rocks.
IMO, there have been three major advances in brake technology since the early 70s. One is narrowing the pad track, to reduce the variation in rotor temps from the inner diameter of the pad track to the outer, which caused lots of coned rotors on early disc brake bikes. Another advance was the change from gray iron (early cast iron) to extruded cast iron. Better friction coefficient and less prone to exploding when drilled. The last would be floating or semi-floating rotors, which allowed rotors to be slightly off center in any of the three planes. Floaters self center, so no longer heat up unevenly like the early fixed rotors did. That allowed rotors to be much lighter and thinner than early rotors and was the end of heavy one piece solid cast iron rotors. Some brakes had AL carriers before floaters were developed… (LM I and Converts were a couple of early examples)…afterward all rotors were separately mounted on aluminum carriers. Good for wheel rate ratios…right Mike!!! You're one of the few people I know who is concerned with wheel rates.
CAUTION: Do not put floaters on a bike with early calipers like FO8s, unless you are qualified to make serious modifications to the calipers. The pistons on FO8s cannot extend far enough out of the body of the caliper to come in contact with a 5mm rotor and then safely retract once you have even a little wear on your brake pads. After very little use, they will extend, contact your rotor, not retract and lock your brakes.
Disc brake forks
Updated: 2011 Mar 15
Disc brake fork shroud / headlight ears
Updated: 2011 Mar 15
Thanks to Paul Linn for providing me with these photos and measurements. The left shroud is part number MG# 13496241. The right shroud is part number MG# 13496141.
- The drum brake shroud measures 137⁄8 in length.
- The disc brake shroud measures 143⁄4 in length.
- Please use these written measurements rather than attempting to read the tape measure as Paul had to hold the tape measure and take the photo at the same time.
Fork shroud comparison between drum brake and disc brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Photo courtesy of Paul Linn.
Fork shroud comparison between drum brake and disc brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Photo courtesy of Paul Linn.
Fork shroud comparison between drum brake and disc brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Photo courtesy of Paul Linn.
Disc brake hub flange / bearing carrier / disc carrier (disc side)
Updated: 2011 Mar 15
Thanks to Paul Linn for providing me with these photos and measurements. The disc side hub flange is part number MG# 13613641.
- Flange is 39.5 mm wide
Disc brake hub flange / bearing carrier / disc carrier (disc side) for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake hub flange / bearing carrier / disc carrier (disc side) for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake hub flange / bearing carrier / disc carrier (disc side) for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake hub flange / bearing carrier / disc carrier (non-disc side)
Updated: 2011 Mar 15
Thanks to Paul Linn for providing me with these photos and measurements. The non-disc side hub flange is part number MG# 14620301.
- Outer flange is 22 mm wide; 39.5 mm wide overall
Disc brake hub flange / bearing carrier (non-disc side) for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake hub flange / bearing carrier (non-disc side) for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake hub flange / bearing carrier (non-disc side) for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake installation on a non-disc brake loop
Updated: 2010 Mar 31
This information originated from posts made by Greg Field on the old Topica Loopframe_Guzzi news group (which has now moved to Yahoo!) and also from a small comment sent to me by email from Marty Ray.
Putting a T3 front end on a loop frame
There are three approaches to putting a T3 front on your Eldo, but none is easy. Here are the options:
- Adapt the T3 triple trees to the Eldo. This is easiest, but you then lose the heavy look of the Eldo front end (no fork shrouds). You'll almost certainly have to use the T3 fender. The T3 axle will work.
- Adapt the T3 forks to your Eldo triple trees. This allows you to keep the fork shrouds and Eldo fender. There are at least two ways to do this:
- Have tapered “adapter caps” made that bolt to the top of the T3 forks. These match the taper on the inside of the top triple tree. Bob Nolan has made these. I can ask if he'll make more. This limits you to the non-FAC dampers. See below for caliper and fender considerations.
- Get new disc-Eldo tubes made by Forking by Frank to use with the T3 sliders. Have him make the tubes with the ID threads at the top like the ID threads on the drum-Eldo tubes (different location for the O-ring, from what I remember). This leaves you to find a way to adapt damper rods to the top of your forks. You're unlikely to find the stock set-up for a disc Eldo, so here's how I'd do it: Center-drill your drum top caps for an 8-mm stud to affix the T3 damper rods to your top caps. This is a basic set-up that I have never actually done. Better would be to get FAC dampers and have the hex cap at the top turned down (or filed down) to fit inside the tubes. Then, remove the air stem from the top of the FACs, and screw it onto the stud you have added to your top caps. I have done this. See below for caliper and fender considerations.
- Have custom top triple tree made to clamp non-tapered tubes of the T3. This would likely be very expensive but may be easier in the end than option 2. See below for caliper and fender considerations.
Caliper and Fender Considerations
If you do not have a disc front fender, you can use the drum-type, if you do the following:
- Swap fork sliders, left to right, which puts the calipers behind the sliders. This leaves room so that you can use the stock fender braces (or at least I was able to on the one I did).
- Then, cut off the strap on each side of the fender that used to mount to the fork sliders. Best would be to weld them back on in a position that can then mount to the T3 sliders. Likely, though, no problems would ensue from leaving them off.
- Insert the axle from the right (nut on the left).
Other Considerations
- I cannot remember what I used for axle and spacers. I think I had some metal turned off of the shoulder of the drum-brake axle.
- You'll have some daylight between the end of the fork shroud and the top of the slider, especially if you fit the longer G5-length springs and dampers. No harm in this; it just looks a bit odd. The reason for the daylight is because the fork shrouds are longer for the disc brake forks than for the drum brake forks. Drum brake fork shrouds are easy to find…disc brake fork shrouds are not nearly as common.
- There's probably other stuff, but I just can't remember it right now.
Disc brake - installing FAC dampers into original disc brake forks
Updated: 2012 Feb 13
Thanks to Tom Halchuk for sending me this information in a personal email. In Tom's own words:
These are the procedures for updating a disc brake Eldorado to an FAC front suspension. Use these procedures if you plan on going through the trouble of upgrading the stock dampers/springs to FAC dampers and progressive springs.
Read the complete set of procedures to put your mind at ease about this upgrade.
Parts were purchased at MG Cycle
One note before we start. There will be about a 3⁄8 in increase in length to the stock setup. The difference is the height of the hex head on the FAC cap. No big deal.
Parts needed:
- Your original stock disc brake Eldorado front end
- FAC Dampers
- ATF or fork oil
- Stock Drum style cap
- Progressive springs (Wirth or Moto Especial)
- Fork seals
- 80 mm × 8 mm × 1.25 mm bolt
Here we go:
- The FAC damper schrader valve will be removed.
- The FAC damper is going to have the outer threads and the hex milled off to the same diameter as the damper.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.Photo courtesy of Tom Halchuk.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.Photo courtesy of Tom Halchuk.
- A stock drum style cap will be center drilled (no more than 1⁄2 in deep) and taped on the bottom to the same thread as the schrader 8 mm × 1.25 mm. Run the same tap into the freshly milled FAC top as well.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.Photo courtesy of Tom Halchuk.
- The 80 mm × 8 mm × 1.25 mm bolt is cut into 1 in studs. The stud is installed with red loctite into the Drum Style top. Blue loctite is used on the FAC aluminum top.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.Photo courtesy of Tom Halchuk.
- Insert the fork tubes into the triple tree. Make sure the tube is fully inserted into the upper triple tree. Tighten the lower triple to hold tubes in place.
- Assemble the FAC damper to spring with cups and circlip
- Install fork seals
- Install FAC assembly into the lower fork leg.
- Fill lower leg with 160 cc fork oil/ATF fluid.
- Insert lower fork leg onto appropriate tube. Eagle should be pointed forward.
- Push lower leg up until the FAC assembly sticks out.
- Hold the top of FAC assembly with vice grips. Use blue loctitite on the FAC top threads. Attach steel drum cap and washer to FAC unit.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.Photo courtesy of Tom Halchuk.
- Lower the leg.
- Tighten the assembly to the fork tube. Loosen lower leg and re-tighten top cap.
- Repeat for the other side
- When both sides are installed. Insert mounting dampers for instrument panel.
Disc brake line bolt size
Updated: 2012 Apr 05
Thanks to Charlie Mullendore of Antietam Classic Cycle for providing this information on the Yahoo! Loopframe_Guzzi news group. In Charlie's own words:
When I added the second disc to Cam's Eldo, all of the banjo bolts were 10 mm × 1 mm. The port on the junction block for the brake switch is 10 mm × 1.25 mm, though. Every Tonti Guzzi I've worked on has been 10 mm × 1 mm.
Disc brake master cylinder
Updated: 2011 Mar 15
Disc brake master cylinder rebuild
Updated: 2011 Jun 30
Thanks to Charlie Mullendore of Antietam Classic Cycle for providing this information on the Yahoo! Loopframe_Guzzi news group.
To remove the piston/seal assembly of your master cylinder, you'll need to insert a rod of the largest diameter that will fit into the outlet hole and then drive the piston assembly out. The retaining ring is sort of tapered with an edge that catches and holds the whole thing together. I use a 14 mm Craftsman socket and my bench vise to press the new ring and piston assembly into place.
I made a “hone” for the master cylinder bore out of a length of 3⁄8 in aluminum rod. I drilled and tapped a hole into the end of it, cut two discs of Scotchbrite approximately 5⁄8 in in diameter and then affixed them to the end of the rod with a screw and washer. Chuck the rod up into a drill and have at it - works very well.
Disc brake master cylinder size
Updated: 2012 Mar 05
I extracted this information Greg Field, Rob Anderson, Steve Odell, and Charlie Mullendore of Antietam Classic Cycle off of the Yahoo! Loopframe_Guzzi news group. Vintage Brake is another good source for disc brake ratio information.
In Greg Field's own words:
Brake master cylinder-caliper ratios are all trade-offs. If you want more power, go to a smaller master cylinder. The trade-off for the power is longer lever travel. I don't mind lever travel, so long as I can lock the brake before the lever hits the handgrip. Given that, here's what I think is ideal:
- For a single F08, and 11 mm master cylinder is perfect. A 12 mm master cylinder is nearly perfect. A 13 mm master cylinder works pretty good.
- For dual F08s, and 13 mm master cylinder is perfect. A 15 mm master cylinder works pretty well.
Here's what I advise customers who call my shop:
- If you think you will be keeping it single-disc, get an 11 mm or 12 mm master cylinder. The 11 mm master cylinders in big-twin sizes (most are tiny ones with short levers for dirt bikes) can be tough to find.
- If you are sticking with single-disc for now but might want to upgrade to doubles later, get a 13 mm master cylinder. The 13 mm works pretty well with a single F08 and works stunningly well with twin F08s.
In Rob Anderson's own words:
Guzzi use 13 mm front master cylinder as std for the Cali where is actuates a single 4 pot brembo caliper onto a 320 mm disk. I am using a 5⁄8 in (~16 mm) master cylinder to operate twin 4 pot brembos (with asymmetrical piston sizes). In practice the 5⁄8 in front master cylinder is pretty handy for dual F08 calipers as well and easy to get hold of from a wrecker, CB900 with integrated reservoir if I remember correctly.
In Steve Odell's own words:
16 mm master cylinder makes the squeeze no different than a 12 mm - 13 mm for a single disk. I have tried 12 mm, 13 mm, 15 mm and 16 mm. 16 mm was best. Use stainless braided lines. Using rubber lines is a worthless waste of pressure. And get rid of that brake switch that is normally on the lower tree T junction block. That's another waste of pressure and a place where air bubbles get trapped and you never can get them completely out.
In Charlie Mullendore's own words:
The 13 mm master cylinder that I swapped Tom the 15 mm one for made a huge difference in the stopping power of my customer's Eldo. With the 15 mm m/c it was like grabbing a hand full of rock and the bike barely slowed at all. Stainless lines and EBC HH pads made very little difference.
With the 13 mm m/c it now stops very well without being too grabby and has nice feel. This is how disc Eldos should have been built in the first place! No issue with bleeding the system even with the stock switch in place - the lever is nice and firm. Neil is going to be very happy!
Disc brake rear
Updated: 2011 Nov 14
If you are looking to replace the original rear drum brake with a disc brake, here are a couple of ways to mount the master cylinder.
Greg Field's method
Thanks to Greg Field for posting this information on the Wildgoose Chase forum. In Greg's own words:
Drums work OK, but it seems I have to grease everything three time to get through a Seattle winter. I'm tired of that, so I grafted on the disc rear end from a T3 before I left for the National in June (2008). Here's one way to do it, for anybody who's interested. The T3 swing arm, u-joint, rear drive, wheel, axle, caliper hanger, and caliper bolted on directly, so no point in recounting that. The difficulty was in mounting a master cylinder. That's easy if you're willing to weld mounts onto the frame, but I needed to mount the m/c without making any undoable mods to the frame. I decided to try to make a plate that mounted to one of the engine-trans studs at the rear and to a standoff from an existing hole in the footboard mounts at the front.
Here's a view of the plate. I hacksawed it from thick aluminum plate and file-finished to shape. Then, I bent a tab at the rear and drilled it to go over the engine-trans stud. I drilled and tapped it at the front for the stand0ff bolt, and fitted it up.Photo courtesy of Greg Field.
Here's the standoff at the front. It's stronger than it looks.Photo courtesy of Greg Field.
Here's the rear mount, to the engine-trans stud.Photo courtesy of Greg Field.
Then I trial-fitted an 11mm master cylinder to get it mounted at the right angle for best leverage from a pushrod mounted to the top tab of a T3FB brake pedal. This meant that the m/c was tilted downward slightly, so it's not parallel with the engine. It works great, so I don't care about that. Function was more important to me than looks. I cut the plate for the angle, and then drilled and tapped the plate for the mounting screws and mounted it up.Photo courtesy of Greg Field.
Then, I bent a little bracket for the m/c reservoir. The bracket also mounts to one of the engine-trans studs.Photo courtesy of Greg Field.
The completed set up. Works better than I had dreamed and will sure ease my maintenance burden when the rains begin to fall. Now, to get that DOT 5.1 fluid outta there…Photo courtesy of Greg Field.
Ralf Brinkmann's method
I extracted this information from Ralf Brinkmann on the Yahoo! Loopframe_Guzzi news group. In Ralf's own words:
Please keep in mind - I'll convert to the Guzzi Integral Breaking System, your intentions may differ and possibly will require a MC with smaller diameter. Due to my limited time my long term hobby project is still under construction and not tested on the road.
For the bracket I used two 5 mm flatt iron and rounded edge and seam (behind the visible seam) with a file. If I would make it again I'd cut the bracket as single piece out of a square tube (S235JRG2 DIN 2395) - no welding and rounding required.
The 16 mm Brembo master cylinder is used on several small block and big block Guzzi twins, e.g. as rear master cylinder on the MG Jackal. The brake rod is a shortened Cali-III rod.
Photo courtesy of Ralf Brinkmann.
Photo courtesy of Ralf Brinkmann.
Photo courtesy of Ralf Brinkmann.
Photo courtesy of Ralf Brinkmann.
Photo courtesy of Ralf Brinkmann.
Photo courtesy of Ralf Brinkmann.
Mike Ittner's method
Thanks to Mike Ittner for sending me the photos and description in a private email. Mike used an 11 mm Brembo master cylinder (Brembo part number 10.4776.50) with a rod and clevis (Brembo part number 70.6002) and a remote reservoir (Brembo part number 10.4446.40) that Moto Guzzi fit to many sport motorcycles, including the 1992 - 1995 Daytona, 1997 - 1998 Daytona RS, 1996 Daytona Racing, 1996 - 1999 1100 Sport Injected, 1100 Sport Carb, Centauro, V11 Sport, 2003 - 2005 V11 Cafe-Ballabio, V11 LeMans, 1100 Sport Corsa (MG# 30666900). In Mike's own words:
The brake push rod is a close fit but clears the transmission linkage by a good half inch and runs between the top of the swing arm and the frame member. With the starter in place the neighborhood will be a little crowded but I don't foresee any problems.Photo courtesy of Mike Ittner.
Photo courtesy of Mike Ittner.
The L-shaped brake rod actuating lever that also acts on the brake light switch was extended an inch in height to accommodate the master cylinder push rod.Photo courtesy of Mike Ittner.
I notched out the battery tray and welded a plate hanging down to hold the master cylinder.Photo courtesy of Mike Ittner.
There is a rod sticking up from the tray to hold the brake fluid reservoir and the brake line runs back to the stock T-3 setup.Photo courtesy of Mike Ittner.
The rear drive, swing arm and rear wheel are also T-3 just to make it all bolt on and avoid modifications. They can be done and are not difficult but I just preferred to have everything match.Photo courtesy of Mike Ittner.
Photo courtesy of Mike Ittner.
Photo courtesy of Mike Ittner.
Disc brake rotor
Updated: 2011 Jun 30
I extracted this information from Steve Odell on the Yahoo! Loopframe_Guzzi news group. In Steve's own words:
Minimum thickness is stated by Brembo to be 5.7 mm.
Disc brake spacer between bearing and fork leg
Updated: 2011 Mar 15
Thanks to Scott Grupe and Charley Cole of Zydeco Racing who posted this information on the Yahoo! Loopframe_Guzzi news group. The spacer is part number MG# 13615641.
The dimensions of the axle spacer for disc brake wheels are (source: Charley Cole):
- Inside diameter: 20.5 mm
- Outside diameter: 26 mm
- Length: 41 mm
Scott Grupe reports that you can easily make a replacement spacer out of commonly available black iron pipe commonly available at hardware stores. 1 in OD pipe is the correct diameter and wall thickness and only needs to be cut to length.
Disc brake wheel spacer for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc brake.
Photo courtesy of Paul Linn.
Disc brake spacer between wheel bearings
Updated: 2012 Feb 13
Thanks to Tom Halchuk for sending me some of this information via personal email. The spacer is part number MG# 14615201. The same spacer is used on single and dual disc brake models.
- Inside diameter: 20.9 mm
- Outside diameter: 27.9 mm
- Length: 76 mm
Disc brake spacer for hub flange / bearing carrier / disc carrier
Updated: 2011 Mar 22
If you do not have the correct hub flange / bearing carrier / disc carrier (MG# 13613641), you can use the hub flange / bearing carrier / disc carrier from a Moto Guzzi T3 (etc.) and then fit a spacer to move it out so that the disc is in the right location for our wider forks. Paul Linn has made these in the past. Steve Odell can make these. Tim Brunner has informed me that Joe Kenny also has the specifications to produce a spacer of the correct width (see photos below).
Here are the specifications for these as provided by Steve Odell:
Besides the 10 mm thickness, the two main dimensions are the OD of 4.790 in to match your bearing carrier OD and the ID of 3.150 in to match the carrier inner flange step for the rotor. Then there is a .200 in step in and step out on each side of the spacer. The secondary ID of the step out for the rotor can be whatever you want it to be but no smaller than the OD of the axle or larger than the edge of the inner radius of the carrier bearing which on mine was about 2.68 in. Actually I thought making one just bigger than the axle would look kind of neat.
Not all of these bearing carriers are exactly the same size. It's just a casting and an old one at that. It helps to have the carrier and rotor on hand when doing it. When [the machinist] first cut this spacer it was a real tight fit on the carrier. He had to put it on the lathe and spin it holding some sandpaper to some spots to lap it in. The only way to avoid this is to make the dimensions slightly large. I prefer a close fit. Then you can bolt them together and polish them as one piece if preferred.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Steve Odell.
Photo courtesy of Steve Odell.
Here are the photos of the spacers that Joe Kenny made for Tim Brunner:
Tim mentions that you will need bolts that are 20 mm longer as well. A length of 140 mm works well.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake spacer as used to fit a disc brake to drum brake Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles.
Spacer made by Joe Kenny.
Photo courtesy of Tim Brunner.
Disc brake top nut and tube sleeve
Updated: 2011 Mar 15
Thanks to Paul Linn for providing me with these photos and measurements. The top cap nut is part number MG# 13504541. The tube sleeve is part number MG# 13504441.
Ralf Brinkman sent me links to some parts that Dieter Nelson had made by Holger Lauer (in Germany). Here is Dieter's information and the excellent machinist work by Holger Lauer. Ralf suspects the smaller fork top nut can by made by modifying the center bolt of the 650 cc URAL flywheel (URAL part number 90407).
Disc brake fork top nut and tube sleeve for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake fork top nut and tube sleeve for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake fork top nut and tube sleeve for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake fork top nut and tube sleeve for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake fork top nut and tube sleeve for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
Disc brake fork top nut and tube sleeve for Moto Guzzi 850 GT, 850 GT California, Eldorado, and 850 California Police motorcycles fitted with a disc front brake.
Photo courtesy of Paul Linn.
