Moto Guzzi Loop Frames - Frame & swingarm
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Table of contents
- Battery tray - putting it all back together
- Center stand stop tab
- Engine and transmission mounting bolts
- Engine mounting spacers
- Paint protection when installing the engine
- Police side stand spring alternative
- Rear crash bar reinforcement for the gussets
- Swing arm bearing cross-references
- Swing arm pivot pin adjustment tool
- Swing arm seal cross-references
- Transmission mounting spacers
- Voltage regulator bracket
Battery tray - putting it all back together
If you've taken everything apart, or have inherited a motorcycle who's battery tray has been creatively modified, it can be difficult to know exactly how everything is supposed to go back together. This is especially true if a larger than stock battery has been fitted, or a non-stock battery hold-down bracket is used, or if non-stock battery hold-down bolts are used. This photo shows all three of these conditions (photo courtesy of Bruce Daniels).
I've put together a diagram of the battery tray that indicates how everything should fit. The drawing isn't to scale, but should provide a good overall indication of how things go together.
If anyone plans to fabricate a replacement battery hold down bracket or bolts, let me know and I'll post the precise dimensions.
| Battery tray | 19 KB | 1 page |
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Center stand stop tab
The stop tab that is welded to the left side of the frame is easily broken off. Unbeknownst to me, mine was already broken off when I took the frame to be powder coated. Only later did I discover my mistake (ah, the things one learns with experience).
I made a replacement tab using an existing stop tab as a pattern. I've included a drawing below for those of you who may need it.
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| Center stand stop tab | 17 KB | 1 page |
To view PDF files, you will need to download and install the free Adobe Acrobat Reader version 5.0 or higher.
NOTE: If you have trouble viewing PDF files inside your browser, try saving them to your computer (right-click the link, then choose the save option). Then, open each file directly in Adobe Acrobat Reader.
Engine and transmission mounting bolts
Foot peg models
Two identical hex head bolts are used.
- 12 mm x 1.5 mm x 333 mm
Floor board models
Two threaded rods are used.
- 12 mm x 1.5 mm x 360 mm (20 mm long threads at each end)
- 12 mm x 1.5 mm x 343 mm (30 mm long threads at one end and 22 mm long threads at the other end)
Engine mounting spacers
These are the aluminum spacers that fit on either side of the engine and through which the large engine mounting bolt with the 19 mm head is fitted.
Both the left and right side spacers are 22 mm long.
Paint protection when installing the engine
Thanks to John Prusnek on the Yahoo! Loopframe_Guzzi news group for suggesting this idea.
When installing or removing the engine from the frame, it is all too easy to scratch the frame in the process. Taping the frame doesn't seem to help much and the foam plumbing pipe insulators are simply too thick to work on the bottom frame tubes. Instead, thin walled plastic tubing is a great solution. This type of tubing is commonly available to cover shower curtain rods.
Police side stand spring alternative
Thanks to Charles Hamer on the Yahoo! Loopframe_Guzzi news group for suggesting this idea.
Harley Davidson part number 50112-99. This spring fits very well, it's also coated with thick plastic and cost USD $4.95. For best fit make sure the ends of the hooks point to the rear of the bike when stand is fully extended.
Harley Davidson part number 50112-99
Harley Davidson part number 50112-99
Rear crash bar reinforcement for the gussets
I extracted this information from Ross Raymond on the Yahoo! Loopframe_Guzzi news group.
Police frames were modified slightly to reinforce the gusset to which the top of the rear crash bars mount. The reinforcement is nothing more than a rectangle piece of steel that was welded in place. From Ross:
It is a bit hard to measure but I got the following: 35 mm L x 22 mm(23 mm) H x 3 mm thick (a little thicker than 1/8").
My plates are about an 1/8" above the straight of the web, and the rear point of the mounting hole is 17 mm from the rear edge of the plate.
These are obviously all done by hand, there is a variation between left and right, I measured the left.
Swing arm bearing cross-references
Thanks to Bob Greene provided key starting information for these cross-references.
The physical dimensions of the swing arm bearings (MG# 92249216) are as follows:
- ID: 17 mm
- OD: 40 mm
- Width: 12 mm
Here are a couple of cross-references:
- RIV 01/02/5010
- SKF 639215
The following physical dimensions are slightly thicker, but work just fine and are much easier to source than the original (thanks to Fred on the Yahoo! Loopframe_Guzzi news group for confirming the fitment).
- ID: 17 mm
- OD: 40 mm
- Width: 13.25 mm
Cross-references for the slightly thicker swing arm bearings:
- Maryland Metric item no. 30203
- FAG 30203A
- RIV 01/02/7203
- SKF (Eur.) 30203A
- SNR 30203
- STEYR 30203
Swing arm pivot pin adjustment tool
I found a great little tool at Harbor freight that is perfect for adjusting the swing arm pivot pins. It is called an adjustable pin wrench and fits the holes in the pivot pins very well. If your pivot pins are frozen in place, this tool will prove entirely inadequate. But, once your pivots pins are free and you've applied anti-seize compound, it works great.
If your pins are stuck, there are a few techniques you can use to remove them:
- Soak with penetrating oil.
- Try turning the pins with a couple of punches, a vice grip, and a lever. I've found that 5/32" diameter punches fit nicely in the holes.
- Purchase the pro-style tool from somebody like MG Cycle.
- Spot weld something (like the jam nut) onto the end of the pin and then use a wrench to turn it.
Swing arm seal cross-references
Two identical seals are used on both sides of the swing arm (ID: 30 mm, OD: 40 mm, Width: 7 mm).
Transmission mounting spacers
I extracted the information about the five speed spacer dimensions from Ray Hale off of the old Topica Loopframe_Guzzi news group (which has now moved to Yahoo!).
These are the aluminum spacers that fit on either side of the transmission and through which the large transmission mounting bolt with the 19 mm head is fitted.
On four speed transmissions, the left side spacer is 57 mm long and the right side spacer is 42 mm long.
On five speed transmissions, both the left and right side spacers are 57 mm long.
Voltage regulator bracket
The voltage regulator bracket mounts close to the rear fender. From the factory, Guzzi used a couple of pieces of rubber trim to prevent metal to metal contact. There are many alternatives to using the stock Guzzi trim. Here are a few:
- Trim-Lok Plastic and Rubber - look under the rubber edge trim section.
- Split a piece of small diameter rubber hose length-wise.
- Pick up a piece of trim from your local auto store.