Bonneville America Forums Forums Technical Forums Performance Mods front sprocket

Hi all.... I'm a newbie. Just wondering about changing my front 17 tooth sprocket to a 16... I feel my first gear is to tall.. Would this change make it any better on take off? And does this lower my mpg... MMV. Oh yea, it's a 09 america.

Not sure how your injection might play into the mix but it makes extra low end grunt on a carbed bike. I run the 16. It will decrease your mileage a little but I can out pull a BB Night Train with 6 spd trans and dyno tune injection.

I am running the original 790 with thunderbike pipes and freak, I have got the TPUSA 904 kit with 813 cams,Fast Fred modified head with bored carbs and intakes that I have to install yet and I'm going to run the stock 16T sprocket. These are not big torque engines and enjoy the rpm's. In my opinion the original 16T speedmaster sprockect is the way to go.

Here's another vote for the 16, I never did understand decreasing acceleration just to make the engine rev a little lower on the highway. At 80mph indicated with the 16 my tach reads 5,000 rpm; still 2900 rpm away from the rev limiter.

Whatever works for everybody.
I'm running an 18 front and a 40 rear on my 03 America. At an indicated 60mph it's turning right around 3000 rpm. I don't miss the low end pull because I ride solo and don't race anyone. Since recently making this change, I've gotten 53mpg and 58mpg on the last 2 gas fills.

It's all in what makes you happy. The 16 will definitely give you max grunt off the line....

Front sprockets are pretty cheap and easy to change. Try it for yourself and see how you like it. My 07 came with an 18 tooth and I went to a 19. Most of my riding is is on country roads between 50 and 75 mph. (pretty much zero city driving) I was tired of trying to go for the elusive (non-existent) 6th gear so the 19 tooth worked fine for me. I do have to drop a few gears for passing but no big deal.

Unless fully loaded with gear and a pillion, no noticeable difference off the line (to me). I guess if you do a lot of city driving and want to go from light to light in the shortest amount of time, the 16 is the way to go.

I'll stick to my 19...

Boy, this stock sprocket thing is confusing. Originally, the Americas came with a 17 and the Speedys a 16. I understand that in 07 they both went to 18. Now, with 09 and later, have they changed again? Is the stock America now back to 17?

I had a 17 originally and changed to an 18. I really like it but sometimes miss the quicker take offs when riding 2-up. I may go back to a 17, but a 16 would be too low for me and I'd always be wanting a 6th gear. On the other end, the 19 would be too high for me. The 18 gears are tall enough.

Obviously, everyone has their own opinion and driving habits.

I'm sure mine is a 17...... Sounds like trump has changed a few times to figure what works best. I like the overall feel of the 17 except on take offs... I need to slip the clutch more than I like... An 18 must really take a good clutch wippin' to get the old girl rolling... MMV.

I'm think the america is still a 17 and only the speedmaster changed.

I'm changing my sprockets in the spring and maybe i'll go up a tooth in front.

I found the 16 to be too short when I first got my Speedmaster (03, carbed). I felt like I was constantly changing gear and I was always looking for 6th. Granted, I was just learning how to ride and discovering what my bike could do. Even now with the 18 I still hit the limiter more often than I'd like but I think the 19 would be too tall.

so far I have tried the 16T that came on the bike. it was on for about 10K miles. an 18T that was on for another 10K. the 16T back briefly (just playing) and now a 17T. The 16 and 18 had the good and bad points previously mentioned but where both useable. The 17T seems like the best fit for my current riding with the least amount of compromise.