Scooterotica

What's the best way of measuring the clutch plate gap?

New plates were tight and worked Olay initially but after a good run the clutch wouldn't work like the gap wasn't big enough (which led to an interesting ride home!). I've got some smaller steels but want to make sure I haven't overdone it.

Cheers

John

Yes, I had the same recently: new clutch plates expanding when hot so the gap between the plates closes up to nothing, meaning the clutch doesn't fully disengage. Using a clutch compressor tool, fully compress the clutch, then check the gap between the top (chamfered) and the top friction plate, where the friction plate "ears" are. If less than 1mm, take the clutch apart and bend up the "ears" on the bottom friction plate a tad so the plate sits lower in the crownwheel, so increasing the gap a bit when the clutch is compressed. Worked for me
Edit: ...or use thinner steels to get the 1mm gap as you suggest...

1mm is too small, 1.5 should be the minimum to prevent drag but 2mm is probably safer especially if you get in a situation (very steep slope) where you have to slip the clutch a lot. Much more than 2mm will result in slippage. I've also mixed different thickness friction discs as well as steels to get the clearance right.

Thanks guys. Pete described my experience exactly. Clutch worked at first but then when fully hot just wouldn't disengage. I measured the gap using a feeler gauge but I didn't think it was very accurate and it seemed to be a little over 1.5mm. I think I'll go with that based on Coasters comments. Thanks for your advice. Cheers.

Ideally if you're measuring something like this you should use two feeler gauges, one either side so it's even.

Also check all the corks and steels on a flat surface to ensure there's no warping.

No problem. Hope you get it sorted. From my recent experience, 1mm is the minimum gap (from cold) that will work. As Coaster suggests, a bit more will allow for greater expansion due to clutch slipping in traffic, etc (we don't believe in hills hereabouts...). If it's ok when cold, but tight when hot, you probably haven't got a fundamental problem like an over-thick set of friction plates (as a quick check, all the frictions together, without the steels, should fit in the jaws of a 14mm open-ended spanner) or a badly notched crownwheel.

Yeah I read that about the 14mm. There is only one open ended spanner size I don't have lol!