New Clutch Plates, How And What To Measure?

[glynn]

So my TXT Pro 200 has finally got to the point its clutch drag has got so bad it wont idle, tried bleeding clutch, master cylinder and slave are working fine, so decided id just change the plates for the sake of £40 from <mention of this company is not permitted on Trials Central. Please delete this post>. So basically I have read a few posts about setting up the pro clutch, and it sounds horrible, but needs to be done!. So aparently the plates need be between a certain pack thickness, is this thickness for the whole pack (3 friction plates and 2 steel)? and also the clutch fingers need to be a certain distance from the pack? I have experience with replacing clutch plates, but never within such tight tolerances, usually just throw the plates in and enjoy, but from what I have heard the clutch kits for the pros do not come pre measured.

 

So basically what I need to know are the correct pack thickness (and what im actually measuring) and how to set the finger height

 

Cheers

Glynn

[smarty156]

Measure the total pack (3 fibre plates and 2 steel plates). You need a very accurate gauge (as I found out to my cost!).

If you get a Surflex clutch kit then it comes with 1.3, 1.4, 1.5 & 2 x 1.6mm steel plates. Use the 1.3 and 1.5mm plates and it should be spot on.

Finger height (measured from top of fingers to upper lip of inner clutch basket) should be around 17mm. Any more and you risk clutch slip and any less will mean a stiff lever.

Watch the YouTube video of the 125 clutch change and just do what they do (i.e. lay the bike on its side).

Watch for the washer around the Kickstart shaft. It will probably stick to the clutch case when you remove it so take it off and put it back on the shaft before it gets lost.

No need to drain the coolant.

Any questions ask as I've recently done it a few times (see my posts in the clutch topic below!).

Replace the clutch cover gasket too (I'd recommend the black metal reinforced ones rather than the cheap paper ones. They're reusable whereas the paper ones aren't).

Edited May 27, 2016 by smarty156

[cbutler]

Soak the clutch pack in oil for 24 hours BEFORE you measure it, it WILL swell.

[lineaway]

 You actually did not need new plates, you just needed the correct finger height. 17mm.

[baldilocks]

So how does he adjust the finger height without changing the plates ?

[smarty156]

You can't.

If the clutch is dragging and he has the correct lever adjustment (must be 3mm of free play at the lever before you feel resistance) then I would say the fibre plates have probably swollen to the point that the clutch pack (and therefore finger height) are well out of spec. To bring it back into spec he could possibly replace 1 or both metal plates with thinner ones. Will require careful measuring and replacement metal plates. Or just replace the whole clutch pack and be done with it (which will give him a complete new clutch). If the fibre plates are swollen that much why not replace them?

I'd go with replacing the whole pack. A Surflex one is £60 and you'll have spare different size metal plates for the future too.

Edited May 28, 2016 by smarty156

[baldilocks]

I agree with you smarty so that's why I've asked

[glynn]

Fitted new DP clutch kit today, required abit of sanding on a flat surface to get it down to 9.75mm pack size, and finger height was 17mm, although not all fingers were perfectly the same height, one of them stuck up about 1mm higher, and when I tried the bike it had horrendous clutch drag, twice as bad as before, any tips? going to strip it down again tomorrow.