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Sooner or later, you will need to change your tires. Either they will have worn out, rotted out, or been mutilated by some road hazard. When that time comes - and it may come at the side of a road a long way from help - you will need to know how to change your tires. I suppose you could wait for help or push the bike to the nearest dealer, but if you are armed with the knowledge you need and the appropriate tools, you can be back on the road and having fun a lot sooner.
Fixing a flat on a tubeless tire can be as easy as simply inserting a plug and re-inflating the wheel. But, since Moto Guzzi loop frames are blessed with tube tires, a flat always requires removing the wheel from the bike and then removing the tire from the rim.
I've watched car tires being changed at the local tire shop ever since I was a kid. But before I tackled the job myself with my new tires, I sought information. I found that information at a site that Adam Glass put together. Rather than repeat any of the information here, just jump over to his site for a good read.
Good rubber is a necessity. I once read that the combined contact patch for the both the front and rear tires is the size of the palm of your hand (David L. Hough - Proficient Motorcycling). That being said, just about any tire you purchase today will be better than the tires available 30 years ago.
I think it is a usually a very good idea to purchase tires as close to the manufactures original specifications as possible. Modifying tire sizes can have a dramatic effect on the handling of the motorcycle. That's not to say you can't make modifications, just that the consequences may or may not be desirable. Here are the Moto Guzzi specifications for all V7, Ambassador, and Eldorado models:
Here would be my choices. In making these selections, I chose touring or cruising tires because that's what I do with my Ambassador and I like to get as many miles out of my tires as is safely permissible. If you choose sport rated tires, you can expect greatly decreased tire life (but all that gooey traction will let you ride the bike up a wall).
When viewing these selections, keep in mind that I tried to find the tires I think would be best for the style of riding I do with my Ambassador. I chose to include some brands below for which the tires they currently offer don't really meet my needs. I included these selections so that individuals who choose to be loyal to a particular brand would see it listed here. In the end, the tires you choose to put on your motorcycle are your own business.
Width: Most modern tires are now specified in metric widths. However, the Guzzi documentation specifies 4 inches as the appropriate tire width. A little math will tell you that 4 inches is equal to 101.6 mm. So, a 100 tire is the closest you can get to the factory specification. It is possible to fit a 110 or a 120 on a loop and still clear the fenders.
Height: Most modern tires specify the height as a percentage of the width. As near as I can tell, back in the day when Guzzi specified a 4 inch wide tire, the tire was also 4 inches high. That is, the height was 100% of the width. Finding a tire that is the same in both height and width is not easy with many modern tires. Instead, most tires applicable to loop frames will have a height that is 90% of the width.
My first set of tires were 120/90-18 front and rear. I thought they were fine until I put on my second set of tires, 110/90-18 in the rear and a 100/90-18 up front. Wow, what a difference! My skill level in the twisties went way up immediately. The bike turns much more quickly and I love it. No more 120/90-18s for me.
That being said, some very well respected owners like to run the wider 120s.
Yes. I'm not currently aware of any tubeless tire that will damage inner tubes.
The common format for these numbers is AAA/BBC-DD (e.g., 110/90H-18). Explanation:
The common format for these numbers is A.AA/BBC-DD (e.g., 4.00/90H-18). Explanation:
The common format for these numbers is ABCCD-EE (e.g., MT90H-18). Explanation:
| Code | Speed rating (in miles per hour) |
|---|---|
| Unrated | 95 |
| S | 112 |
| T | 118 |
| H | 130 |
| V | 149 |
| Z | above 149 |
| Permissible Rim Widths (in.) |
Metric Width (mm.) |
Standard Width (in.) |
Standard Low Profile (in.) |
Alpha Numeric Codes |
|---|---|---|---|---|
| Examples | ###/90-18 | #.##/90-18 | #.##/90-18 | M#90-18 |
| 1.60 1.85 |
70 | 2.75 | - | G |
| 1.60 1.85 |
80 | 3.00 | 3.60 | H |
| 1.60 1.85 |
80 | 3.00 | 3.60 | H |
| 1.85 2.15 |
90 | 3.25 | 3.60 | J |
| 1.85 2.15 |
90 | 3.50 | 4.10 | L |
| 2.15 2.50 |
100 | 3.75 | 4.10 | M |
| 2.15 2.50 2.75 |
110 | 4.00 | 4.60 | N |
| 2.15 2.50 2.75 |
110 | 4.25 | 4.25/85 | P |
| 2.15 2.50 2.75 |
120 | 4.50 | 4.25/85 | R |
| 2.15 2.50 2.75 |
120 | 4.75 | 5.10 | S |
| 2.50 2.75 3.00 |
130 | 5.00 | 5.10 | T |
| 2.75 3.00 3.50 |
140 | 5.50 | - | U |
| 3.00 3.50 |
150 | 6.00 | - | W |
| 3.00 3.50 4.00 |
160 | - | - | - |
DISCLAIMER: DO NOT ATTEMPT THIS MODIFICATION. DESCRIPTION IS PROVIDED HERE FOR ENTERTAINMENT PURPOSES ONLY.
Inspired by Greg Field's write-up in the MGNOC newsletter about his tubeless conversion on his Eldorado, I decided to make the same modification to my Ambassador. Here is what I did:
Alternatively, have Wheel Works do it for you.