Topic: Is there something wrong with my clutch?

[roach374]

I've got my '72 CB500 up on a stand, and haven't ridden it yet (or even really fired it up for more than a couple of seconds). I replaced and tensioned the clutch cable, but now I'm noticing that the rear wheel spins freely when the bike is in neutral, and much *less* freely when the bike is in (e.g.) first, with the clutch fully pulled.

Obviously, the ultimate test would be to put it on the ground, fire it up, and try to ride it, see if the bike moves forward while the clutch is engaged, but I'm not quite ready for that yet (since the bike is in pieces).

So I guess my question is: Should I expect the wheel to spin as freely in first, with the clutch engaged, as it does when the bike is in neutral?

And if this is *not* normal, how do I fix it? (the clutch cable is a motionPro kit, for CB500, but it's at max tension right now, so can't really tighten it up anymore).

[CaptFatCat]

What happens when you apply the rear brake while wheel is spinning in neutral?
And what happens when you apply the rear brake while wheel is spinning in 1st withe the clutch in?

Im building a 750 that sat or 15 years and the clutch was stuck. It wasnt to hard to free it.

[HondaMan]

In a word: no. The clutches in these bikes are wet clutches, which are designed to slip when the engine is running and the lever is pulled, which allows oil to be slung into the faces of the clutch plates by the spinning clutch hub, to disengage them. They physically separate about 0.005" or so then, and the oil between the plates provides the 'slip' to allow the transmission's constant-mesh drag to be reduced enough to let you shift. It is not a complete friction release, like that found in a dry-plate or single-plate (e.g., car) clutch. And when the engine is not spinning, it doesn't spin the oil between those plates, so they don't separate at all, then.

[roach374]

What happens when you apply the rear brake while wheel is spinning in neutral?

... The wheel stops spinning?

And what happens when you apply the rear brake while wheel is spinning in 1st withe the clutch in?

The wheel doesn't spin "freely", so I couldn't tell you. Like I said, it's up on the stand, and I can't actually start it right now, but that would be the ultimate test.

[roach374]

In a word: no. The clutches in these bikes are wet clutches, which are designed to slip when the engine is running and the lever is pulled, which allows oil to be slung into the faces of the clutch plates by the spinning clutch hub, to disengage them. They physically separate about 0.005" or so then, and the oil between the plates provides the 'slip' to allow the transmission's constant-mesh drag to be reduced enough to let you shift. It is not a complete friction release, like that found in a dry-plate or single-plate (e.g., car) clutch. And when the engine is not spinning, it doesn't spin the oil between those plates, so they don't separate at all, then.

Got it. So first-gear-clutch-in should feel stiffer than the bike in neutral. I guess *how* stiff will come down to how the bike behaves on the ground, under power, so I'll wait until then. In the meantime, I pulled apart the shifter (not the clutch, but the left crankcase cover, where the clutch cable goes in), cleaned it up, and there isn't really any way to get it wrong. All the parts seem to be in working order and well-maintained.

[HondaMan]

There should also be a little steel ball (about 1/4" diameter) in the hole of the clutch lifter: it bears against the end of the long shaft that goes thru the engine to the inside of the clutch. Without the little steel ball, you will most likely not have enough clutch adjustment to actually lift the clutch pressure plate. These often get lost, then the bike suddenly has "clutch troubles", and it gets parked, usually after the chain was changed and the ball fell out, but no one noticed....

[roach374]

There should also be a little steel ball (about 1/4" diameter) in the hole of the clutch lifter: it bears against the end of the long shaft that goes thru the engine to the inside of the clutch. Without the little steel ball, you will most likely not have enough clutch adjustment to actually lift the clutch pressure plate. These often get lost, then the bike suddenly has "clutch troubles", and it gets parked, usually after the chain was changed and the ball fell out, but no one noticed....

This was the first thing I checked, and the ball is still in place. Thanks!