gear ratio question

[woods_rider1]

I installed a 1-tooth smaller C/S sprocket on my '01 250, changing the final drive ratio from 3.71 to 4.00, I could have achieved the same ratio with a 56 tooth rear sprocket. My question is, with the final drive ratio being the same, (13/52 or 14/56) is there a difference in the manner that the engine reacts to different gearing? Will it rev quicker with a smaller C/S sprocket? will it need more clutch out of a corner with a larger rear sprocket? Is there any benefit to having one sprocket combo over the other as long as the final drive ratio is identical?
Thanks Guys

 

[KDX220rm]

Woods,

I dropped the front sprocket down one on my 2000 250exc as it was cheaper in price. But now that I know I like a smaller front sprocket, I will go back to the factory front sprocket and increase the rear sprocket 3 teeth as with a smaller front sprocket you are causing the chain to turn around a tighter radius and increase wear on the chain and swingarm buffer.

 

[23jayhawk]

As far as your engine is concerned, its just a ratio, and you should not see a different response. Torque multiplication is torque multiplication. (With the one exception that the larger rear sprocket will have higher rotating inertia, but I doubt anyone could feel the extra flywheel effect.)

However, the two different sprocket combinations set up different angles between the pull-side of your drive chain (the top) and the swingarm. I would have to work through the kinematics on this, but basically each combination should create a unique moment around the swingarm pivot. I think this can lead to different behavior in the rear suspension, when you are hard on the gas. I believe I have read somewhere that Pro-level riders can feel this difference.

Perhaps Eric will be able to comment on this.

 

[ktmrandy]

A couple things to consider weither to change the front or rear sprocket are clearance. If you are in rocky or bad terrain you may want the smaller rear sprocket to prevent damage to the sprocket. How well will the sprocket fit with the chain guide? The smaller front sprocket will cause the chain to wear quicker but how much may not matter. I went smaller on the front and smaller on the rear to help keep the rear sprocket out of the rocks. This may be lighter and allow a shorter chain also.

 

[Jaybird]

You won't have a problem going with the 13t front.
Only if you do not clean,adjust, and lubricate properly will a smaller front "make" your set-up wear faster. Yes, a smaller front does require more work to get the job done, but if you are cleaned, lubed, and adjusted correctly it will not make a difference on longevity.
If you do see a considerable difference when using a 13t front, then you have a problem in one of the three afore mentioned areas.
Clearance should be your biggest concern. And I also agree that the set-up can minimally effect your suspension action.