s2r800 - clutch drag

[ducpainter]

The steels only vary by 1/2 mm. Measure.

It's difficult to hold a stack in one hand and get an accurate measurement with the other. Try to keep both sides in contact. Tape might help. Are the friction plates different colors? If so what color are they?

Clutch springs, unless they coil bind won't cause drag, assuming a properly bled clutch slave. Have you zip tied your lever to the grip with the bars turned to the right, master as high as possible, overnight? The most common cause of clutch drag is air in the hydraulics.

[pmazdan9]

The steels only vary by 1/2 mm. Measure.

Will do!

It's difficult to hold a stack in one hand and get an accurate measurement with the other. Try to keep both sides in contact. Tape might help. Are the friction plates different colors? If so what color are they?

I'll put them on a table with just enough of the stack left hanging so I can measure it, then rotate and repeat few times. Or I'll just measure them from table to top of the stack. Hopefully that will give me some satysfying readings.

They have different friction material pattern. They look similar or the same to these:
These were on my s2r, they look identical: click
These or similar looking ones came with 620 clutch: click

Not sure what's the difference between them. Looks like both sets fits s2r800 and 620.

Clutch springs, unless they coil bind won't cause drag, assuming a properly bled clutch slave. Have you zip tied your lever to the grip with the bars turned to the right, master as high as possible, overnight? The most common cause of clutch drag is air in the hydraulics.

Iv'e tried it, I guess I'll try again after bleeding and messing around with clutch pack.

[Howie]

If I see no air bubbles and it doesn't feel spongy, I can only assume there's no air so yes you're right, but I can't think of any way to make sure it's 100% air free?

https://www.youtube.com/watch?v=6OnQmWnDFvA  Air that you would never notice in a car is significant with your bike.

AFAIK clutch can drag if steels are warped! I can't be 100% sure if mine are warped as I don't have perfectly flat surface at home to check. Basically I mixed steels from 2 sets and picked the 'best' ones.

A free maybe method would be take the steels, two at a time, hold them together and look for a space.  It is unlikely they are all identically warped.  Better would be buy a straight edge or you could ask a local shop if you could use their surface plate or straight edge.

[stopintime]

Is the outer/last plate put in it's own slot?

[pmazdan9]

Thank you howie I bough few syringes and I'll give it a go! I've heard of reverse bleeding but never done it before, looks a lot easier than traditional method!

stopintime yes it is

[pmazdan9]

I picked up my bike this weekend back from the garage, took it home to inspect the clutch again. Looks like my steel plates are warped. First I measured all steels in few different places and IIRC the highest difference was about 0.5mm. I've another set of steels from old clutch but they're not great either. I measured random plates in stacks of 2-3 and picked up the best ones. I got it down to about 0.2mm and ended up removing one steel as well, the stack height is still above 50mm.

I measured friction plates as well and they are different too. I'm guessing the friction material is worn unevenly due to warped plates, unless this is normal?

Anyway, I've put the pack back in, removed extra washers (I've put 2 on each spring previously) and voila! It doesn't drag at all!! I'm over the moon I know it's probably not the best solution, I'm pretty skint after recent service, if it gets worse I will replace the whole clutch pack - point is, I know what's the issue now.

Oh, I also changed oil and filrer - silkolene super 4 semi-synth 10W40 and K&N performance filter. In the end I didn't have to bleed clutch for the 100th time which is great!

Thanks for all your help guys once again!!

[koko64]