clutch

[TER]

How often should you replace the disks? Is it good for the life for the life of motor or should it be done after a certain number of races? Also does everyone run a stock setup or performance  disks?

[VMS Motorsports]

Not really a race/time decision. They are easy to look at, so just check them periodically.
I've gotten 3 race seasons easily (75-80 races+) out of a Barnett clutch with the coil spring conversion

[Gimpster]

 I have a sweet little tool that tells me when it is time to replace clutch discs. It is called a digital vernier caliper. The life of the clutch can't be just pegged at a certain time for replacement. Too many variables. The 2 biggest killers of clutch discs (other than heat) are pressure plate springs that get weak and the other is not using the correct motorcycle oil for the engine. Just any old 20w-50 oil is not best for your engine because they do not have polymeres that hold the molecular structure of the oil together under compression after it goes through the gearbox plus most 20w-50 oils not formulated for wet clutch applications like missing friction inhibitors and detergents that are safe for the clutch. Take like Castrol 20w-50 oil, put it in the engine and the oil will break down from compression between the gear teeth and will leave deposits baked on the clutch discs which cause it to slip. Slipping clutch causes heat and that in return makes the clutch springs lose tension. I run the set-up like Jim does and have had never needed to replace a clutch disc pack with regular oil change policies to keep the oil in the clutch fresh.

~Gimpster~

[IraceLegends77]

Ran a road race over Thanksgiving weekend and getting a  2:50 gear rolling is hard on a clutch.......LOL

[Gimpster]

Hahaha...exactly, you gotta wind that rubber band up real tight and let her rip !!

~Gimp~

[fsracer92]

I have a sweet little tool that tells me when it is time to replace clutch discs. It is called a digital vernier caliper. The life of the clutch can't be just pegged at a certain time for replacement. Too many variables. The 2 biggest killers of clutch discs (other than heat) are pressure plate springs that get weak and the other is not using the correct motorcycle oil for the engine. Just any old 20w-50 oil is not best for your engine because they do not have polymeres that hold the molecular structure of the oil together under compression after it goes through the gearbox plus most 20w-50 oils not formulated for wet clutch applications like missing friction inhibitors and detergents that are safe for the clutch. Take like Castrol 20w-50 oil, put it in the engine and the oil will break down from compression between the gear teeth and will leave deposits baked on the clutch discs which cause it to slip. Slipping clutch causes heat and that in return makes the clutch springs lose tension. I run the set-up like Jim does and have had never needed to replace a clutch disc pack with regular oil change policies to keep the oil in the clutch fresh.

~Gimpster~

Is there a spec for the discs and plates? How do you check spring tension?

[justfreaky]

I have a sweet little tool that tells me when it is time to replace clutch discs. It is called a digital vernier caliper. The life of the clutch can't be just pegged at a certain time for replacement. Too many variables. The 2 biggest killers of clutch discs (other than heat) are pressure plate springs that get weak and the other is not using the correct motorcycle oil for the engine. Just any old 20w-50 oil is not best for your engine because they do not have polymeres that hold the molecular structure of the oil together under compression after it goes through the gearbox plus most 20w-50 oils not formulated for wet clutch applications like missing friction inhibitors and detergents that are safe for the clutch. Take like Castrol 20w-50 oil, put it in the engine and the oil will break down from compression between the gear teeth and will leave deposits baked on the clutch discs which cause it to slip. Slipping clutch causes heat and that in return makes the clutch springs lose tension. I run the set-up like Jim does and have had never needed to replace a clutch disc pack with regular oil change policies to keep the oil in the clutch fresh.

~Gimpster~

Is there a spec for the discs and plates? How do you check spring tension?

Do you have a repair manual? The specs are lited in that. I can look it up, but not until Monday or Tuesday. Specs are listed online.

Steve

[fsracer92]

I do have a factory repair manual. I just wasnt sure if the aftermarket clutch discs and pressure plates maybe had a different spec...

[justfreaky]

I do have a factory repair manual. I just wasnt sure if the aftermarket clutch discs and pressure plates maybe had a different spec...

Barnett seems to be the main replacement disc and springs. There are some cheaper versions. Don't think they are as consistent on there specs though.
Check your discs and plates with a caliper (as Gimpster says). That should give you any indication if you are within spec.

Steve