Topic: Clutch freeplay is signficantly different cold vs warm

[fizzlebottom]

I have adjusted the clutch by the book with as much precision as possible. It performs just fine with no slipping at all. Clutch plates and friction discs all looked mighty healthy when I last had it apart. I did not measure springs though. The cable is a brand new Motion Pro cable and is routed correctly.

The issue is that I can make final adjustments when the bike is cold. Once the bike warms up, the clutch freeplay increases: Not enough to cause actual problems during riding, but more than I want, and I don't think a 100% healthy clutch is meant to behave like this. If I make fine adjustments at the lever once it is warm then everything feels good. When the bike is cold again, the clutch cable is too tight and I have to loosen it at the fine adjuster again to reset freeplay.

Again, no slipping. Could it be that the spings are worn and need to be replaced? Does cork material on the friction plates degrade or swell in some way that allows them to 'squish' with pressure?

What would be the troubleshooting process here?

[bryanj]

Nothing wrong, its because of metal differential expansion cold to hot

[Oddjob]

It would help if you said what bike it is, most have a different type of clutch mechanism.

[HondaMan]

The CB500 was famous for this, and it was one of the bigger reasons Honda modified the engine to become the CB550 version, with the clutch lifter closer to the clutch. The engine width grows considerably on the 500 as it warms up: the proper adjustment for those was to take out ALL the cable slack and lifter play when cold, period. Then when it warmed up it would engage at somewhere between 1/2 and 3/4 of the clutch lever's travel.

[fizzlebottom]

The CB500 was famous for this, and it was one of the bigger reasons Honda modified the engine to become the CB550 version, with the clutch lifter closer to the clutch. The engine width grows considerably on the 500 as it warms up: the proper adjustment for those was to take out ALL the cable slack and lifter play when cold, period. Then when it warmed up it would engage at somewhere between 1/2 and 3/4 of the clutch lever's travel.

Yeah, interesting. This is a CB650, so based on what you say that should have been solved well before 1982. I'll just live with it for now I suppose, or adjust the clutch to take out all the free play like in the 500.

[PeWe]

CB750 clutch like that too.
Important to not tighten too much at the handle when warm, it can slip next time when it is not fully warmed up.
Enough  to stand still with gear in without dragging.

Fiddling with the clutch adjuster during rides a hobby

[fizzlebottom]

Fiddling with the clutch adjuster during rides a hobby

I really have always done this, but honestly never knew if it was correct or not. Tucking it away under "works as intended"

[leovich]

My K0 did the same thing with 3 clutch packs. First was an all new honda parts with the slanted cork, same behaviour from a aftermarket kit. The last kit I used was the “easy change” type from yamiya that use 2 different type of metal discs. This last one is the best I tried, no more clutch problems, no more jumping at take off and no more “vibration” from clutch when take off at low rpm. This kit is also the first one that don’t change so much the lever free play from cold to hot, but for avoiding this kind of behaviour it is imperative to screw the clutch central nut to the prescribed value