Bonneville America Forums Forums Technical Forums General Tech 19 tooth

I finally got around to putting a 19tooth front sprocket on.I've only had the chance to do a couple of miles with it but I'm liking it.Give it a bit more throttle in first but after a small hesitation it's good to go.
I'll get a decent ride on Thursday and try it out properly.

Good work.....keep us posted please...I'm going there come spring.........

I put a 19 tooth on last summer. Best thing I a can say is ride it like a 4 speed with an overdrive.

I really like it.

I'll test it out tomorrow Bill .Long straights and a twisty climb up and over a mountain.I'll report back then but the couple of miles I've done I'm liking it.

I hated it, lost way too much bottom end grunt.

I never tried a 19, I felt like I lost too much low end grunt with an 18 on my 790. I settled on a 17 as compromise because the stock 16 was too buzzy highway speeds.

I have found 17T x 41T for stock circumference rear tires and 16T x 41T for the 200mm x 16s I run, to be fairly close to ideal (YMMV) for the up/down/flatland terrain here in the PNW . If I lived in Flatbush, Iowa or Illinois, 18 x 42 would probably be fine. My point is by losing or gaining a tooth on the rear sprocket, you gain or lose roughly a half value of final ratio, compared to changing the primary sprocket up or down a tooth.

Thanks Ryk, when it comes time for a new chain I will try 17/41.

Well I went for a 100 mile + ride today and the bike performed great.
It was highway riding with a mountain pass to climb coming and going.Around town I only needed to use first gear a few times.I really didn't notice much difference in take off.I was giving it a bit more throttle.
My friend who did the job reckons he got 80Kph in first gear and 120kph in second.I didn't try.
On the highway, cruising at 120Kph felt like cruising at 100Kph used to.No tingling hands like I used to get after running for awhile at 120Kph.
Coming back over the mountain I only needed to change down into 4th gear near the sumit.
Overtaking a double trailer semi at 120kph I was doing 140kph before I knew it ..Mileage seemed better too 5.3 litres for 100km.Before running at the speeds I did was about 6+ litres per KM Liking the 19T very much so far but I don't know how it'd be carrying a lot of gear, or two up.
P.S. my stock sprocket was 18T.

My stock sprocket was a 16 and still run that. You won't notice a big difference in 1 tooth.

The engine doesn't seem to be working so hard,less vibration.I like it

It seems that everyone has their own preference when it comes to gearing but for me the original 16/42 setup is a perfect fit. These engines are not big displacement potato, potato power plants and enjoy turning rpms which put them squarely into their power band. They respond well while providing both good performance and very reasonable fuel mileage in the upper rev range and you can actually pull top gear in virtually all conditions e.x. windy, hilly, two up etc. These are only my opinions from riding my 03 since new and having tried a couple different different gear changes. I know that with it now being a 904 I could pull more gear but as of yet have not dug out any of the other barely used sprockets I have which are just gathering dust. Maybe some day who knows. Lol

I agree Kit it is a personal choice, but it is not expensive or hard to do so it is fun to play with.

the stock America 865cc gearing was 18T/42T on mine.I only went up to 19T on the front, but I'm happy and as you say Bill it's one of the cheapest modifications to do.

Do you have a tacho Paul, I would be interested to know what your revs were at 100kph..

Sorry Peter no tacho but the engine seems purring along at 100kph to 120kph though.I overtook a B double Semi at a short burst of 140 Kph and that was smooth with more to go.

I had 19/42 on my '05 SM with stock tires. I loved it. My current BA has 19/41 with a 25.5" tire. Still love it. When/if I finally get around to doing engine work, I plan on going steeper yet. I had plenty of inmates tell me I would never be able to do stop and go riding in town. I have probably seven years of riding with both combos. Don't let anyone tell you to not go steep...

With 15/44s you can get wheelies, on demand at lowers speeds.

I tried a 17 tooth for awhile but went back to the stock 16 tooth. Better for going fast on curvy Kentucky roads!

A 19T front sprocket with a 42T in the general area where I live would result in a lot of shifting 'tween 4th and 5th gear and inadvertent lugging (not good) of the engine. A combo of 17T-41T (my fav for OEM tires) or 18T-43T is all the taller final ratio I would go in hill or mountain country. I'm not willing to give up the power/torque to the back tire you need for passing SMVs or touring loaded down for a little real or perceived smoothness. But to each their own to suit the topography you may encounter and the load you haul.

Thats interesting SMJoe, I'm running a 41..18 combination and my tacho reads around 3200-3300 at 100kph (62mph) I would have thought the 19 would read under 3000... although I dont really know how accurate my tac is..

Sorry Peter I forgot to reply to you.

And I don't know how accurate my speedometer is plus now that the tire is 11 mm more in ht I am not sure how accurate anything will be.

Just picked up a 19 tooth, hopefully, this keeps me off the top end of the bike but then again I'm a dumbass and keep the speed around 9- MPH or 130 KPH if not faster. Hoping I don't lose too much in the bottom end but then again I can always downshift it to get that acceleration.

Ride it like a 4 speed with overdrive and you will be fine. Don't be afraid of the top end of the RPM range.