I'm swapping out the 121 x .66"-lug track for a 1.25" on a 2002 Indy 340 for my son. The sled really doesn't matter since the question is general in nature. I've done a search on here and can't really find a direct answer.
I'm thinking I should gear this sled down for the new track since it will now spend most of its time off-trail. I want to slow the sled down a little and hopefully gain a little more "pull". The upper gear is a 17T (jackshaft) and the lower a 41T. The biggest lower gear I can get is a 43T that will still fit the case. The real question is how will this affect the clutching, if anything? Would I need to do some clutch mods also? Should I just mod the clutch and bag the gears?
Any thoughts appreciated!
I'm thinking I should gear this sled down for the new track since it will now spend most of its time off-trail. I want to slow the sled down a little and hopefully gain a little more "pull". The upper gear is a 17T (jackshaft) and the lower a 41T. The biggest lower gear I can get is a 43T that will still fit the case. The real question is how will this affect the clutching, if anything? Would I need to do some clutch mods also? Should I just mod the clutch and bag the gears?
Any thoughts appreciated!
Lowering (higher numerically) the gear ratio can affect clutching as you are not loading the motor as hard and it may over rev on the top end. Adding tip weight will compensate for this and clamps the belt tighter in the primary, which is a good thing.
Last edited:
That's kind of what I thought. However, if you do tip weights on the primary will that basically counter-act any advantage gained with the shorter gearing?
(By 'advantage' I mean 'better pull' in deeper snow.)
I'm also having difficulty grasping the concept that changing clutch weights will alter the top end RPM. Isn't the belt at the top of the primary at higher speed/RPM no matter how fast it got there?
(By 'advantage' I mean 'better pull' in deeper snow.)
I'm also having difficulty grasping the concept that changing clutch weights will alter the top end RPM. Isn't the belt at the top of the primary at higher speed/RPM no matter how fast it got there?
Last edited:
Fixed my post above so it was clear which way gearing was going.
Anyway, you may want to read this write up. Should answer your questions above: How gearing effects clutching and rpm
Anyway, you may want to read this write up. Should answer your questions above: How gearing effects clutching and rpm
Last edited:
Got It. I read that before but must have missed the part at the end about the primary weights. I think I'll run the machine as is and note the RPM peak. Change the track and gearing, then see what I get for peak RPM. I'll adjust the weights to bring the RPM back down to the OEM range. Sound about right?
Thanks for your help!!!
Thanks for your help!!!