View Single Post
Old January 15th, 2012, 12:01 PM   #16
choneofakind
ninjette.org certified postwhore
 
Name: .
Location: .
Join Date: Feb 2011

Motorcycle(s): .

Posts: Too much.
MOTM - Feb '13, Feb '14
Quote:
Originally Posted by aschika1 View Post
I think some of the manufacturers of the gears are claculating the ratio using the diameter of the gear and not the # of teeth.
Wouldn't that give you the same result as comparing teeth but take a lot more work and time? I've never heard of people comparing the diameter of sprockets; just the teeth.

The final drive ratio is just that; a ratio of the drive shaft sprocket to the rear wheel sprocket that tells you how often the engine will be turning for every revolution of the rear wheel. Seeing as the teeth are all going to be a set distance apart since the chain links are all a set size, it would be easier to just figure out the final drive ratio by comparing the numbers of teeth on each sprocket. In this case, 1 tooth is 1 unit. The diameter doesn't matter because the number of teeth determines the circumference of the sprocket, which is really what matters since the sprockets won't have the same angular velocity, but will have the same radial velocity.

for example, stock gearing is 14/45.
45 / 14 = 3.21
57 / 18 = 3.16 note how similar those two are.

That was a ton easier than needing to find the diameters of each sprocket.
choneofakind is offline   Reply With Quote