Interesting information.I talked to my mechanic about the bigger front sprocket and he said we can't do it because it messes with the speed sensor for the ECU and if I change it the motorcycle won't run right because it will try adjusting the fuel delivery trying to get the speed sensor synced up. He also said it will void my warranty.
Well I bit the bullet and now have a 19 tooth front on my 2007 injected America.
Doesn't seem to have made any difference at all to the starting or running BUT boy is it a better ride,hang on to the lower gears a bit longer,cruising speed about 2-300 revs less at 110 kph,for me a much more refined ride.
Not checked the speedo against GPS yet but will do when I get back to France.
It only cost around €25 non Triumph but can't see how it would avoid warranty,you could always swop back if needed too when going to the workshop not a big job.
Sorry bud i was talking about the front sprocket which one tooth is the equivalent to 4 on the rear thats why the differance is so much .I haven't lost any acceleration and I haven't had any issues riding in town, I don't know if you guys have even ridden a Street Twin but I'm hear to tell you it has more than enough torque to pull a rear sprocket with one less tooth, my only complaint about this bike was when you are riding at 85 to 90 mph which is how fast they drive on the interstates where I live the motor seemed to be straining until I made the change to a smaller sprocket.