View Full Version : Sprockets & Acceleration...

03-26-2003, 10:03 AM
hi all,

I was just wondering how to obtain a better acceleration by changing sprockets ...... ... better add 2 teeth to the rear (wheel) sprocket or, subtract 1 tooth at the front sprocket ??

how much will change by doing this operation ? :eek:

03-26-2003, 01:50 PM
If you have the Cup bike (US) and the Cup Manual, there's a gear ratio chart you can use. I believe dropping a tooth in front will have a slightly bigger impact.

One reason to change the rear sprocket is that you can drop some weight by switching to an aluminum sprocket from the stock steel, though aluminum will wear more quickly (proper chain care minimizes that). Also, if you add too many teeth in back, your chain might not be long enough, though I think two teeth should be okay (my bike came with a longer chain to accommodate a larger range of sprocket sizes for racing).


03-26-2003, 04:16 PM
At the short Firebird E race course in Phoenix I run 13/44 gearing. This is the best I can do with the stock chain length. If I wanted to run a 45 out back, I would need to add a link. Terrific acceleration with this gearing!

03-26-2003, 04:20 PM
Hi, there is an ideal ratio for the front and rear sprockets, it's 3:1 (as far as I remember!). If you go very different from that then you'll effect the geometry between the swing arm pivot and the drive/driven points of the final drive which will upset the suspension and handling. Because of the 3:1ratio there's no point in adding three teeth to the back as it's the same as dropping one on the front which is easily adjusted out on the chain tensioners. I run my one with one extra on the back and one less on the front, that gives a maximum speed of around 120mph but lots of wheelie-tastic acceleration.

03-26-2003, 11:30 PM
Driven divided by drive....14/42=3.000 ratio,better accel than 14/45=3.214 ratio.Going up one tooth in the front is like going up 3 teeth in the rear,BUT,you'll notice the difference more in the rear sprocket.

03-27-2003, 02:20 AM
Ok, soon I will test one of these configurariotions...
I imagine that there is no radical difference between a DID professional chain or a Regina one... , anyway best buy should be an X-Ring one....

.. and about the Rear sprocket ? Alluminium is worth to use it ?

03-28-2003, 09:53 AM
I don't know if it is "worth" it or not, but it is all I have ever used and it has no wear problems that I have experienced. Benefit of less rotating mass is a plus for racing.