Bonneville America Forums Forums Technical Forums Performance Mods Sprocket change

Got a questions for you intelligent fellows.....simply put-want to go faster with less RPM, how do I go about doing that, change the sprockets?

Thanks.

Try going up one tooth on the front sprocket. They only cost about $20. and a fairly easy change.

I went up a tooth from the stock 16 to the 17 tooth from Brent. I'm very satisfied with this mod. Lowered the rpm for any given speed by about 500 rpm (or one could say increased the bike's speed at any given rpm. )

rwright is wright!
One more tooth on front = three less teeth on the rear.
Take your pick. I went from 17 to 18 on front and loved it until I realized how much my bride was gonna be with me.
I went back to a 17 tooth and am happy, since Triumphs have always loved higher RPMs than that other brand of classic.

I think I've actually seen a 19-tooth counter sprocket advertised ?!?!

Moving from a 17 tooth to an 18t front sprocket on my America was magic.

Brent sells a 19T also. I have it on. Not recommended for heavy loads or regular two-up riding. 1-up under 200lbs the gears are major tall with 5th being strictly overdrive for the highway.

I agree with AL, the 18 tooth lowered the rpms just enough for me to not wish for a sixth gear. I will get a 19 tooth from Brent (www.speedmaster.com) to have on hand for the rare long interstate trip. If everything goes well, I intend to ride (the rest of the family will fly) from central VA to Vegas this summer for my daughter's national dance competition. If that trip works out, it will be the longest bike trip 4500 -5000 miles) of my life. The 19 tooth should work well for interstate highway use. If anyone has any feedback on the 19t, please let me know.
There are many helpful tips and methods for removing and installing front sprockets here on this forum, just search under sprocket and then under sprocket removal. FYI, if you choose (I don't recommend) to use an air impact wrench, don't put the bike in gear to help prevent sprocket from turning. The tension on the chain that is placed on it when the anvil in the wrench attempts to turn the nut will be temporarily released between hammer/anvil impacts inside the wrench possibly allowing clearance between transmission gear teeth. The result can be that the teeth in your tranny are repeatedly (torque/release, torque/release, and so on)impacted almost as hard as the parts in the air wrench. The hammer and anvil in the wrench are designed to stand that treatment, but our transmission gears can't benefit from it. I've only changed the sprocket on my TBA once, but used the method where you hold the rear brake to keep the sprocket from turning. It worked for me and didn't risk any shock loads on the tranny or rear wheel rubber bushings (bushes according to Triumph). The engineers (many of them with exceptional knowledge, wisdom and experience on the Triumph vertical twins) on this forum can elaborate on impact gun use. Also, if you don't have a torque wrench that reads in Newton meters (Nm), buy one and use it. They are invaluable in reducing stripped and/or broken bolts/studs and loosened fasteners. Another suggestion is to get a Triumph service manual for your bike. There is a huge amount of information in it. Good luck and let us know how it goes.

Satxron, I see you have the 19 t. What performance mods have you made to your bike? My '02 TBA has Triumph long off roads, some rejetting and stock airbox/filter (for now) and the Summer screen. Do you have power enough for extended high speed (75-80 mph) riding? Also, do you have any high speed gas mileage estimates? Not that it matters that much, because my butt usually determines when I need to stop, not the fuel level, but I was just curious. At 80 or so, I might burn enough to need gas before my butt needs a break.

I, like many others was constantly searching for that invisible 6th gear that just was not there. On my 2005 America I switched from the stock 17 tooth front to a 18 tooth up front. Two up riding in western pennsylvania I like it much better. Although I would not consider the 19 tooth for my area. It would be mainly for the flatter states. The work of changing the sprocket? Very simple. The hardest thing about it was locating a 36mm socket.

Jerry

Got my 36mm socket at Sears too, but it was on the floor of the cabinet un-labelled. Gotta geep those eyes peeled!

Good info guys, I appreciate it. Have to do a search on the instructions on swapping them out. I am guessing that you can swap them out without removing the rear tire, that sound right?

Thanks again all!!

Yup. Check Pat's site.

I havn't done much in the way of mods per your question. Snorkels and AI are gone. 45 Pilots and 130 mains. Drilled out the last baffle in the stock pipes and enlarged the 2nd baffle. Handles the sprocket very well. Gears are way tall for the highway. I drive 90% over 50 MPH. Generally don't even consider 5th til about 60 or so.

If you do a lot of 2-up and are over 350lbs combined I would advise on the 18T not the 19. First gear is a dog with weight to get moving, can't be good for the clutch. Once moving it handles the gear very well.

Benny,
I know I have seen Pat's site on here before, suppose you could save me some searching and post it here for me? I would really appreciate it.

Step one. Return to the performance mods forum

Step too, click on the sticky topic "new addres for site" at the top

Step 3, proceed to pat's site

Step 4, call me a smartass

Question.
Since speedy's love higher rpms, why would you want to lower them? I can see the advantage in gas milage, but are there any others?

Cheers
wendell

only 28 days till i see my baby

I like high rpms too. So I rarely use 5th unless I'm on the highway just makin time getting somewhere. Now I just use 3rd, sometimes 4th bangin around the back roads.

Well... okay, maybe when the mints run out I'll order some more and get them to throw a sprocket in the box as well.

Wendell

Well ya know, too meaning also, 2 meaning second... kinda the same thing

Well ya know, too meaning also, 2 meaning second... kinda the same thing

Matt,

Here's another good sprocket thread to consider:
Sprocket Thread

Sticking with 17 teeth myself for now. I don't ride two-up and don't do many highway miles at 70-80 for extended periods of times at this point.

Regards,

Tom

Thanks Tom, by the sounds of the "new method" it should be fairly easy to do. Guess I need a lift to do that though huh?

I recommend it. I bought the Craftsman model everyone talks about. Makes chain cleaning/oiling, rim and tire cleaning a breeze. Not too pricey. I originally made the $20 bike lift, but didn't like the idea of balancing the bike on a 4" piece of wood. You're welcome to it if you want to give it a try. I'll be in NNews next week.

Regards,

Tom