Clutch yet again (sorry)

[sc0ttie]

So i got my bike back from the garage on thursday. Some people may know, i had a new set of clutch plates and springs fitted (EBC parts) i rode it home, fine. I rode to work and back friday (30 miles) all fine. I went out on a ride today, about 50 miles. All was fine until about 35 miles, after that everytime i gave a handfull of throttle in any gear, the clutch would slip badly making the engine revs etc. The garage who drilled the bolt out for me, adjusted the clutch cable for me on thursday, they test drove it before i got it back.


So why would my newly installed clutch start slipping now, after 2 days of riding fine, then  at the end of a long ride it starts slipping every time I try to open it up?

[Fazerider]

What oil do you have in there?

[sc0ttie]

It is what the garage put in, they replaced the oil, it is a motorcycle only garage so i would assume they used motorcycle oil. Plus if it was car oil it would have been slipping before now?

[Fazerider]

I don't know how long it takes for the plates to get enough moly on the surfaces to start slipping when the wrong oil's been used, but it was only a guess.
Other possibilities are clutch cable adjustment (bottom end may need adjusting, not just at the lever)… though again, I can't see why it should change in the course of a few days, let alone in that direction. Worth checking though, because otherwise it's a matter of looking at the clutch itself again.
Did the garage say exactly what the original slippage problem that they fixed was?
Was the pressure plate OK after your slight mishap of tightening it up in the wrong position? If the base of some of the wells that the springs live in was overstressed they could be failing and that would give rise to slippage.

[Deefer666]

Its one of a number of things:


Adjustment on the sprocket housing is wrong
Clutch (stack) basket assembled incorrectly
Steel plates are badly scorched from where the clutch was slipping and should have been replaced


Possibly incorrect oil but I doubt it, shame your not closer because I would take a look

[sc0ttie]

I can check the clutch cable adjustment tonight, I suppose I just don't understand how it can work perfectly for a few days and then start slipping badly, it's not gradually deteriorated, I was on a ride and suddenly started slipping a lot. I presume since the garage fitted the clutch it has all been assembled correctly, it is a good garage with a good reputation. Also the clutch cable was refitted and adjusted on Thursday by another garage which was closer to me. Will try adjustment first tonight.

[Deefer666]

Maybe the lock nut on the grub screw has worked loose?

[Billy:)]

Take it back to the garage maybe they'll sort it for you for free if they want to keep up their good reputation! 

[Fazerider]

Knew I had it somewhere: this is what my clutch plate looked like after I'd focced up by tightening the screws up with it in the wrong position.
It's possible that even if yours looked OK after doing the same, that there were hairline fractures which have now broken with use and excess stress from stiffer springs.

[sc0ttie]

Thanks for posting this pic Fazerider, and thanks to all who posted advice. I did check the clutch plate for any damage after you posted this but mine was all fine. The garage who fitted my clutch had the clutch out today, checked it all over, found 2 things.
1. that 3 of the springs where ever so slightly shorter than the other 3 by about 1mm.
2. a couple of the steel plates were glazed.


replacement springs fitted and steel plates cleaned and glaze removed with a bit of fine wet and dry paper. all reassembled and adjusted and now the bike rides like new.


I don't know how the springs could have lost about 1mm in height or even if that was the problem. Unless of course the wrong springs were delivered to the garage and fitted. I really don't know if the glazing of the steel plates affected it but they were checked to make sure the thickness and flatness was still good on them and they were ok. I was just happy that my bike is running as it should be now and i had no extra charge to pay, they sorted it for me. To celebrate I took it out for a good ride locally to me and ended up at the Thames estuary here in Kent

Details 12983892 10156882103535085 1564423421327026558 o

12983892 10156882103535085 1564423421327026558 o

[Jules-C]

Good to know there are garages that value customer service and reputation more than a quick buck. 

[Punkstig]

I remember replacing the clutch on my thundercat with a full etc replacement, had if on and off a couple of times, checked the springs and strangely enough 3 were ever so slightly shorter than the other 3, so I refitted alternating them, had no problems that way but they were stiff as hell (that'll be ordering the heavy duty version) so replaced the original Springs!