Might seem like a stupid question, but on the clutch disk, i can see where the rubbing bit is.

But how much is too much. how thick should they be to be safe? how thick are they usually to start with? where do i measure from?

seems alright. no rust, no oil, no environmental exposure.

One would say well its a perishable item anyways, just replace it. and they aren't all that expensive. but at the same time too, if its still got half or more life left, how often do you replace a clutch anyways? might last a bit longer, and it doesn't take long to undo 4 bolts and change it anyways if it does go kapoot...

But if its passed its happy days, i wouldn't question a newie...

(its a 200mm spring type from a type 3. was working great. HD definitely an upgrade consideration, but there is no wildly extra ordinary hp pushing it, and it was pushing a heavy type 3 wagon initially)

photo! IMO its not about thickness, its about wear... if its really smooth , its probs not going to work well.

best way is if you have no adjustment left if its out if it under 2mm from to plate and to replace it is best a bugger of a job to pull the motor out because you were trying to save a dollar

best trick is to use a 7mm open ended set spanner if this slides onto the clutch plate its time to renew the clutch plate....cheers steve

As some of the girls 'might' say, it's not the size but how thick.
As Steve said, but also you can see one side of the friction disc/material worn more than the other looking at the edge is another good indicator.

you may also save an engine pull later as replacing it now at least you know its new and will last the distance

relace all the bits clutch plate pressure plate and thrust race

was the clutch slipping or as Matt say its the thickness that counts