Bonneville America Forums Forums Technical Forums General Tech Here we go again

I need to change out my chain and sprockets. I was thinking of goign up to an 18, possible a 19. Right now this is how 5th gear looks 70mph about 4k on the tach, 80 4.4k and 90 about 5.1k

I'm thinkin ya got an 18 0n there with those numbers.

18 is a good choice.

I find 18x42 to be pretty good overall on my cammed 865.

Just checked I do infact have an 18! Mine is and 07 nad I thought they were stock with a 17. Looked at the rear closer also and its a 42 sunstar, the chain is a DID. I bought this bike new from the dealer with 2 miles on it. This seams strange to me.

My '05 Spdy came with a 16 T and my '06 originally with a 17T. I'm starting to wonder, if they just grabbed whatever they had at the top of the parts basket (or the most of) during assembly?

I just called TPSU where I bought the bike, they said most all of the bonnies from 05 up had a 18T and that they buy the sprockts and chains in bulk.

Speedy had 16t in 05 and the America had a 17t. They changed that in 06 to 17t IMHO.

18t to 19t is a major change. At 70 you will be about 3600 RPM> Have had a 19t for years and love it. Its not a 1st gear bike but all gears are way tall, makes riding the bike a joy for me with a lot less shifting and very low RPMs cruising meaning no vibration, less exhaust noise and IMHO less wear and tear on the motor.

My 07SM came with 18x42 new.

16/44 is great around town and in the twisties. 5300 rpm at 80 mph, 6400 at the ton and pulling strong.

My 02 had a 17,then my 05 came with a 16,have18 on the garage wall where it stays most the time,use 16 when I want to show my friends who has the torquies bike amoungst us.They agree.

Close Enough:

Every 500rpms constitutes a 10mph change in speed.

Vera Lynn
42/17 45mph @ 3000rpm

Cinnamon Girl
42/18 50mph @ 3000rpm

Well since I DO have an 18T I may go up to a 19 cause I still find myself loking for 6th occationally and slowing down isn't really an option.

I like the 19 to reduce the drone of constant high speed revs when on the interstate or other wide open roads. The sound of the America with TORs revving through the gears is sweet music, but after getting into 5th gear, I like the lower rpm for cruising. Changing from a 17 tooth to a 19 tooth will give you about a 10.5% reduction in ratio/revs and from a 18 tooth to a 19 tooth is about a 5.15% reduction. In the end, it's a matter of personal preference, as the Americas/Speedys are tough and can handle all available ratio combinations easily. I have a new 17 tooth Triumph brand sprocket for sale in the classifieds that I have reduced the price on and will take reasonable offers on as I won't be going back to the 17/42 setup anymore.

I still run 16/42 and like it all around and I take multi-state trips over the summer.

Never really thought of this before but couldn't I achive similar results of going from a 18t up to a 19 instead by leaving the front an 18 and changing the REAR to a 40T?

They both were SM.

darn it i just bought an 18 from Marty..... maybe my 07 has an 18 already on it, but my rpms are higher then that at 120 kph i am running about 4200 or so i beleive. MARTY!!!!!

I know at one of you has got to be using a JT for the front. Anyone know the right part # for a 19?

When I bougth my '07 america it had a 17/42 set-up,but I went to a 18/42 to lower the hwy rpms.I just changed again to a 41/18.(found the 41 on clearance!)This set-up is great for one up riding,but I find myself having to down shift alot when riding two up.So, I'll be changing back to the 18/42 !Hope this helps.

I went ahead and order a kit with the 19 from FastEddy this am. Now I see why everyone likes him so much great guy. He called me back to answer a question ans end up BS'n with me for about 15 minutes.

I also picked up this from cycle gear today for only $30 normally $90.