Rational

Power = Torque x Rotational_Speed

Just as the bike can potentially produce the same amount of peak power regardless of which gear it's in, it will also produce the same power before and after a sprocket change. The torque at the back wheel will just be a little higher, and the rotational speed of the back wheel will be a little lower.



Man, with both my bikes out of commission I almost wished for snow today!

smb123

Ok, we were communicating on different wavelengths. I understand the point you're getting at.

Yeh, the moment of twist (which is all that torque is) on the back wheel will be higher.

Darkmind

Why doesent somebody run a stock bike against a bike with -1 frount and +1 in the rear and post up the stats and let us do the compareison.
Just my

Rational

That's one way to prove it to yourself, but there is a simpler way. To get the maximum speed out of your bike, it needs to top out at its peak power level. Let's say you know your bike hits peak power output at 13,500 rpm. Find a nice stretch of racetrack and top it out in 6th gear. If it's running right at 13,500 rpm when the speedometer stops rising, then there's no point in changing your gearing if your only consideration is top speed. If it tops out at 14,000 then you'd go a bit faster if you geared it up a bit-- but if it tops out at only 13,000 then you could go a bit faster if you geared it down a bit. If the same bike tops out at a mere 12,000 you might go faster in 5th gear than in 6th.

Of course changes in elevation, wind, grade, gross weight, tire pressure, fuel quality, size of the coat you're wearing, etc., etc. can all change what your optimal top speed gear ratio would be.

Super_Rob

it's interesting and slightly refreshing to hear all this smart talk.

cstmgsxr

just gear the damn thing down for $20, if you dont like it, change it back!!!!

itsmegb

damn their gettin it on with scientific sh@#,my heads spinnin over chay, hehehe

RR929RR

I second that

infamy

forget all the science crap. 13 bux bought me a 2down front sprocket.