Is it easier on the transmission to lower the gear ratio on the final drive or the primary? Lowering the primary ratio will increase the torque to the transmission, as I understand it. But the trade off is lower transmission gear speed.

Which is better?

 

Lowering the primary ratio (smaller compensator sprocket) will decrease engine rpm. The rear wheel speed to transmission speed ratio will not change.

The only way to decrease both engine and transmission speed is to change the secondary gear ratio.

Not really sure one way is better than the other, but if you have final drive chain, it would be easier to change the rear sprocket until you find the gearing you like.

 

There are several answers to your question. For Evos and TC88s that have belt drive the easiest is in the primary, by changing the compensator. The primary has to come off to get to the rear drive and belts are more expensive than chains. TC96s are more complicated.

However as you have a rear chain, it will be easiest to change your rear wheel sprocket, which will probably also require a new chain.

From a technical point of view I don't see any disadvantages to either, except for radical changes in ratios. I changed the compensator in my TC88 from 25T to 21T with complete success and very worthwhile results!

What sort of changes do you have in mind?

 

I have the primary off right now, and was thinking of going to a 21t compensating sprocket from the 25t.

It will be 19% decrease in speed to the transmission input, but also a 19% increase in torque as well. I'd don't want to stress the trans more than this beast of an engine already does.

 

Please explain how this works.

Your engine puts out only so much torque or horsepower. That is all it can pass on to the transmission.

 

I ran a 21T for a few years with no problems. The current owner loves it too! It is raising gearing, not lowering it, that adds loads into the drive line.