In the original pack the friction plates differ, and then the first one to go in is the thickest. However I dont really understand why. But if they are the same it should work in my opinion.

I think because the first friction plate has to sit in a lipped clutch basket. If the friction plate wasn't thick enough it wouldn't touch the bottom and you'd lose some of the clutch grip.

All the Surflex friction plates are 2.3mm so no need to get the right one at the bottom like the original plates. Although maybe the newer plates are the same too?

I think because the first friction plate has to sit in a lipped clutch basket. If the friction plate wasn't thick enough it wouldn't touch the bottom and you'd lose some of the clutch grip.

All the Surflex friction plates are 2.3mm so no need to get the right one at the bottom like the original plates. Although maybe the newer plates are the same too?

 

That would make sense.

I think when I did mine the pack thickness was correct but the finger height wasn't. I don't understand how that can be the case ?

Its ''easily'' fixable. You need to set the pack thickness and the fingerheight spot on and it will work just fine.

Crazybond my clutch pack is 9.85 but the finger height us only 16mm ?

Packt hickness +- 9.75 to 9.85mm

Finger height aim at 17,5mm

Also check play on the lever should have arround 3mm of free play.

Yes that could be the case. I would say the fingerheight is more important than the pack thickness. Also the levers can be bend, spring could be worn etc etc.

 

With 16 it should work, but probably a heavy clutch.

 

There are guys making true academics of it.

 

https://www.facebook.com/2011trproduct/?fref=ts

https://www.facebook.com/trproduct?fref=ts

 

Edited May 18, 201610 yr by crazybond700

Ok. My clutch is still slipping in 5th and 6th. This is after a new clutch pack all measured to correct thickness, finger height spot on and oil changed twice (Putoline Light Gear Oil as recommended by Factory Kev at GasGasUK). Clutch lever is lovely and light.

Was at a very muddy trial today, lots of 3rd gear clutch slipping (deliberate) and blasting with no issues at all. It's just in 5th and 6th.

Any ideas?

 You could see if Kev has one of the original springs. (2002-05) It would be a slightly harder pull, but would eliminate slip.

I've just emailed him to see what he thinks the problem is.

Kev thinks the clutch pack isn't thick enough now, which makes sense. Maybe my measuring skills with a vernier caliper just aren't very good!

Will take apart again and re-measure, putting in a thicker steel plate to see what that does.

Smarty two things I have learned recently which may help.

First of all new plates bed in .1 to .15 mm on first use so if you are setting it up at 9.75 it will be out of spec after the first trial.

Two, are the steel plates brand new ? I swapped plates from an old set to get the right thickness but the clutch slipped. When I stripped it again one of the steels was worn on the underside so I think unless the fibres where lined up perfectly with the groove in the steel plate any measurements I took were incorrect. Changed steels clutch is now perfect

Edited May 23, 201610 yr by baldilocks

It was slipping the first time I rode it so they didn't even have a chance to wear.

Yes, the steel plates are all new.

I'll take it out and re-measure. I have a digital vernier gauge now which should make it simpler to check.

So I've worked out either I can't read a manual vernier caliper correctly or its just wrong. The digital vernier caliper I now have gives a different reading and the clutch pack is indeed too thin.

I'll swap one of the steel plates for the next thickness up (which came in the Surflex pack) and this should solve the problem.

Edited May 24, 201610 yr by smarty156

Often the manual ones go per 0.5 per complete rotation not 1. Maybe something went wrong there?

 Jim Snell has redone his clutch video. https://www.youtube.com/watch?v=gnLY1IrMvBM