Transmission gear ratio

[Guest Brent]

As fun as the V11 is to ride, I sometimes would like a little more "get up and go" off the line. Since I don't care much about top speed, I thought that I'd look into changing the gear ratio (like one would do on a chain-driven bike by replacing a sprocket). Is it possible to do this, without too much expense, on a shaft-driven bike?

[callison]

Not trying to be snide, but have you tried starting in first gear rather than second? I mean, these things are geared pretty low as it is for first. To make it even lower is going to mean shifting more often in the lower speed ranges and any oomph you gain in acceleration is going to be lost to the interval between power application while you shift. Seriously, I used to have a Fiat 2300S, a car geared unbelievably high for a 2.3 liter 4 speed vehicle. First gear was good to 45 mph, so while I didn't exactly scream off of the starting line, I wasted less time shifting and generally wound up leading much hotter cars up to about 80 mph. Additionally, it is REALLY expensive to change gear ratios on a Moto Guzzi. It can be done, but you're probably looking at $800 or more to change the rear end pinion set if you're changing the overall gearing. Optional gear sets aren't even available for the 6 speed transmission as far as know but it's about $2700 to convert a 5 speed to a 6 speed to get new gear rations. Not cheap. You would do better to have your heads ported of something of that nature or put in a hotter cam. There's a lot of room for improvement in the sport cam profile as it is designed to save valve wear, not make big power.

[Mike Stewart]

I agree with Carl, 1st gear is really low! Work on the engine if you want more go off the line (and maybe the clutch). I think the 11 to 1 compression ratio will be in order along with some head porting and don't forget the Stucchi crossover and powercommander. (how about a Nox system?).

 

Mike

[RichMaund]

I have to agree with Mike and Carl as well.

Compared to all other Guzzi's I have owned, 12 total now, this one has the best low range gearing. All the others felt like I was starting off in 2nd gear. Riding this bike made me feel I finally found a Guzzi with a gear for all occassions!

You can change the ring & pinion in the rear drive. They have made about 6 different ratios over the years. That has to done carefully to make sure they are properly shimmed for proper gear tooth contact. But how will you change the gears in the speedo drive to get the right reading at the speedo? I don't know that those are the same as the older 5 speed tranny sets.

 

May be more trouble and expense than it is worth.

[Guest Brent]

Hmmm, maybe it's just me and the way I work the gas/clutch (and no, Carl, I don't start off in 2nd--good thing you weren't *trying* to be snide). Or maybe it's too difficult for the bike to get my 240lbs (260 including riding gear) moving!

[callison]

Yeah, I can go with you there. The best performance increase I ever got was when my friendly endocrinologist told me to lose weight and change my diet or suffer the ravages of type II diabetes. So I lost 30 lbs and have another 20 or so to go. Oddly enough, the bike now performs better. I could probably chart acceleration vs body weight curves in an attempt to put the Sport into the same category as a piece of nippon hardware, but I suspect that point where that ratio crosses would have me weighing zero. I mean, there's such a thing as being called an air head, but to aspire to it is something else again.

[callison]

Yeah, I can go with you there. The best performance increase I ever got was when my friendly endocrinologist told me to lose weight and change my diet or suffer the ravages of type II diabetes. So I lost 30 lbs and have another 20 or so to go. Oddly enough, the bike now performs better. I could probably chart acceleration vs body weight curves in an attempt to put the Sport into the same category as a piece of nippon hardware, but I suspect the point where that ratio crosses would have me weighing zero. I could carry fewer tools on the bike I suppose, but that's inviting Murphy's Law into action.

[dlaing]

Perhaps you could find a 16in wheel. It would be a lot to pay for a small gain in gearing, the ratio would be just a little better than 69:72. So at 69MPH you would be reving what you would have at 72MPH.

If you get a bonded clutch, they supposedly grip much more aggressively.

Trade up for a 2003, or putting in a high compression piston set should give you the added grunt you want. Not sure how to handle the change in ignition timing requirements if you go the high compression route.