how does gearing affect clutching?

[thewayout84]

This one is really intresting i think
how does gearing affect clutching?
what happens when you gear down a sled, how does the secondary react when the track spins more easily and the resistance is less? what happens with WOT rpms? do you need less spring in the secondary so it will open more easily?
why do you need lighter weights when you gear down?
why is it more efficient too have the largest top sprockets possible?

Everyone that knows anything about this plz write some notes
maybe we could get this in to the cluthing theory thread?

 

[winter brew]

It sounds like you already know the answers....and yes, it works the opposite of what seems logical. Gear down and you will typically drop RPM.
With the secondary seeing less load it will upshift quicker/farther than it did with taller gears (all else remaining the same).
There is a point of gearing too tall or too low, too low and the system becomes TOO sensitive and RPM may fluctuate too quickly for the clutches to compensate.
Another aspect of gearing is... where in the shift pattern does it put you on a climb. This will dictate helix choice (or helix angles can dictate gearing choice as well). Like with the Doo reverse helix, you don't want to gear super low because it will put you in the steeper portion of the helix and make for less belt squeeze/slower backshift....not ideal in a mtn. application with a big, heavy track under load.
Next.

 

[thewayout84]

With the secondary seeing less load it will upshift quicker/farther than it did with taller gears (all else remaining the same).
There is a point of gearing too tall or too low, too low and the system becomes TOO sensitive and RPM may fluctuate too quickly for the clutches to compensate.
Like with the Doo reverse helix, you don't want to gear super low because it will put you in the steeper portion of the helix and make for less belt squeeze/slower backshift
Next.

so you actually would need a stiffer spring in the secondary?
how do you know when you are geared to low? what is to low? give an example on a doo because you seem to be an doo expert

thank you for a very good answer winter brew!!

 

[longhairfreak]

You know you are geared to low when you crush your secondary. The 1st time I squashed my 1160 this happened.