How convex is "convex"? (Clutch plate)

[72degrees]

After the great engine swap last week I've remembered why I'd been switching the clutch stack between engines last year to get a nice 'action'.

Both hubs/baskets are shimmed perfectly, but with one stack the take up is very grabby whichever engine that is fitted to. This consists of all new plain and friction plates - except the thin convex plain plate which has not been renewed. I'm just wondering if these can lose their efficacy over time. I suppose I should compare them but that means having the 'good' clutch apart yet again. I see Mdina Italia has new ones in stock if required. The only other difference is that I also transfer the 'wee vee' hex head clutch nuts and the 'spring assist' washers that are fitted under the spring cups. The bad stack doesn't slip, but I suppose the extra pressure on the other set up might make initial take up a bit more progressive?

Assembly order is as advised by Evguru - half friction plate first in then the convex plain plate 'out'.

I'm just about to smooth the plates (again) but I might also try swapping just the cups and washers as an experiment.

[norbert]

This is the most convex I´ve found, supose that it is nearly original

file.jpeg (35.46 KiB) Viewed 5577 times

[72degrees]

If that's what they are supposed to be like I'd better order a new one!

[72degrees]

The new convex plate supplied by Mdina is indeed much more 'dished' than the old one. Now re-assembled with that and the other plain plates which have been first given a blast with the orbital sander. I remembered that I had to use a full plate rather than a half plate to stop it slipping (even with all new plates). The spring cups looked OK and the length measured as the same as on the other unit (though that uses assist washers anyway).

Too early to be certain but a much more progressive action now just creeping it on the drive. I shall know more after a proper ride.

[EVguru]

The conical plate should be pretty much the same height as the plain ones.

[72degrees]

The conical plate should be pretty much the same height as the plain ones.

I was comparing how much it rocked on a flat surface. The old one was pretty pitted too to be fair.

The improvement may be coincidence, or prove short lived. If it is still grabby after a test ride I'll just go back to swapping the complete stack for Hartland at the end of the month.

[EVguru]

I was refering to the height of the plate on a flat surface, rather than its thickness.

[72degrees]

I was refering to the height of the plate on a flat surface, rather than its thickness.

OK. I didn't get round to that, but I suppose it must certainly be 'higher' than the old one. The comparison with the other plain plates would be a useful diagnostic if you haven't got a new convex one to make a comparison with. I'm hoping not to have it apart again though!