Bonneville America Forums Forums Technical Forums Accessories front sprocket tooth counts

Any thoughts on changing the front sprocket to one with more teeth for lower rpm at highway speed? How will that affect low speed performance? Alex

the 865's might like it more than a 790 would. still possible, you just might need to take it into consideration when taking off or riding 2 up
G

First of all,
Welcome!
Second,
What set-up do you have? And, how much drop do you want?
Uncle Charlie

I have a stock 2005 America with the 790cc engine. More than that I don't know...

With regard to taking off on a 790cc, do you mean I would have less low speed power and find it a little more difficult to get up to speed? Alex

Alex, there is a up and down side to all gearing. If you increase your teeth on the primary gear you make your gears taller. (more top end, longer gear time before shifting, lower RPMs at highway speed) In return for that you loose the quick snap off the line and the high torque through 2nd gear. Once past 2nd gear you are about a gear apart if you go up two teeth. Example would be a 17t gear in 2nd at 4,000 would probably have the 19t gear still in 1st.

Many on the board have moved to a 18t primary gear, you probably are at 17t and find yourself reaching for that elusive 6th gear.

I have a 19 tooth primary and will never switch back. Its up to your personal preferences the bike can handle 16,17,18,or 19 tooth primary gears and run well with all of them.

Thanks for your response... At 60ish mph I'm turning approx 4000 rpm. With a 19t sprocket can you tell me what your bike does? I'd be happier (I think) at 3300rpm or so...

With the 17t on mine (which I thought was stock) I'm hitting 65mph in 3rd, no tach, but I'm guessing 5k or thereabouts.

If you like low rpm cruising switch up. If stock you have the 17 tooth. They are inexpensive and easy to change so try the 18 first. If still not enough then try the 19. I have the belt conversion which fall between the 17 and 18 and is great for long distance but I like the 16 for everyday use and commuting. I do not mind the rpms, actually I prefer running 4-4500 rpm. The motor does not mind either. It runs a bit more rpm than a typical v-twin with more/lower peak torque.

It's your riding habits . Do you ride in town ? Long rides on an interstate ? Two -up ? Hilly or flat ? If it's a mix like mine , leave it at the stock tooth count . Even at interstate speeds , you're not gonna sling a rod .

After 1000 miles on my bike I went to the 19th tooth...Of course to bring the highway RPM's down and save on wear and tear, fuel and oil useage, but also it keeps you from trying to shift into that elusive 6th gear. I absolutely love it (4500 miles later) and will never change! I ride a lot in the city and a lot on the highway to and from work. I have also been in the mountains of Arizona, California and North Carolina with no issues looking for power. My opinion is to go with the 19 tooth...But like everything else, each's own! Good luck, welcome to the site.

I am dropping a tooth to the 16 for some more low end. I don't ride the highway for more than 15 minutes to work and most of my riding is on the streets and hills of good old San Diego.

BTW, thanks for all the good info on this board, I have been lurking around for a few weeks checking everything out.

I run 80mph give or take on the highway all the time with a 16t front no problem. I compare that to Wendys bike and I can top the ton much easier than I can on Wendys America with stock sprocket.

19t for me,but i do long highway rides.but it does not bother me when i ride in town either.A high reving engine just bothers me.19t FOREVER!!!!!!!!!!

I have the 18t. I love it. It seems to be perfect for around town and the highway.

Soren

I rode a 19 for a while and loved it on the highways. My only gripes were if you're not careful to rev it a bit too high for the launch, it induces the occasional conkity conk noises from the con rods etc. on start ups, which would likely leave some metal dust in ones oil. I have a couple million miles of "the less throttle on start up, the better" branded into my brain from my truck driving days, including the recent electronic truck engines that require absolutely no throttle actuation (aka 'idle away technology') for clutch engagement, even on the steepest grades. I guess old habits die hard. The other concern I had was you can hear & feel the engine working pretty hard on the hills with the 19. You have to keep it tached up pretty good or the engine grunts pretty hard. Just my little two cents, but if we asked a drive line engineer about the 19s, (vs. a 42 rear) I bet the answer would be don't do it. I could be wrong. I've since switched to the 18, and it's more forgiving on launches. If you tune for max HP with a 12.x air to 1 fuel type rich mix, the 18 & 19s are a bit more forgiving on launches. A 17.5 would be nice too.

I have never had a konkity konk. Is that like a glangity bang or a clakity clank only louder?

jus messin wit ya Mr. Bucky

Thanks all for the in depth answers to my question about tooth count. Very helpful...I think I will try 18 for a while and not go the the extreme. As a newbie, I don't know why lower rpm appeals to me, but it does.

In any case I Love my Triumph and thank the Gods (all of them) that I discovered that there are alternatives to H-D's ,Jap bikes, and Euro racers. This is much more my style. Alex Proud owner of Bonnie America 2005