A whole lot'o slapping going on....

Just saw the first part of your Q's.... It does not do this with the clutch pulled.

Yeppers.... I think I will just ignore it, until I make a unchainslapping device......

Did you ever check for a tight spot?

Yep.... No tight spot. I almost thought there was, but it was the lube, as the desert went down to 19 deg. F. yesterday morning. A few links were held slightly bent. Both sprockets are true.

Fitted a DID 525 VMX chain..... problem went away. Old chain was the one BMW fitted after the recall. It had no evidence of any stretch. Yay.....

Maybe the auto-clutch has something to do with this. You mention "neutral torque", so the clutch may not be fully engaged like it would be if you were gassing it.

On the other hand if other people have had this issue without the auto-clutch, then it can't be the sole cause.

No. Auto clutch had no change..... I was slapping all over the last 500 miles. New chain did fix it. Stock chain had 4000 miles on it. It began with the supersprox/Woody's 18 inch tubeless combo. Nothing I did could make it go away. Something with the supersprox, and CZ stock chain..... Gone now anyway.....

I fitted a DID Xring and the slap went away with the original sprockets. Total of 52000 on the chain, one really tight section about 6 inches long, and about a 3 inch section almost dead opposite.

My son had exactly the same thing happen on his ZX6, and I put on a very expensive DID chain with the original rear and new front sprocket and it's perfect again.

The chain had a couple of tight spots dead opposite each other.

I'd love to figure out why this happens. Two completely different maintenance profiles. I lube mine like mad, he hardly ever even looks at his. He got 40000kms out of the chain and I got probably the same before I just accepted the slapping. Both bikes have odd numbers of teeth on the front, and non divisible number of teeth on rear so there shouldn't be repetitive wear patterns that I can figure.

I am perplexed as well. Mine was fine, with no slapping, but as woody's 18 inch came with stock gear supersprox. That is when the slap began. I get a slap or two, but nothing like with the stock. I think that perhaps harmonics........

Does the 18 have a bead lock? Out of balance will make the rear jiggle enough to make chain slap.

I fitted an 18 to one of my DRs and it was fine until I hit exactly the right speed...about 90kph, and it literally made the rear hop off the ground it oscillated so hard. I fitted a bead lock dead opposite the original and never had problems again.

I've had front wheels with bead locks do it, and I just remove the lock.

No bead lock. Excel rim. Rim is true, but tire has a small 8mm side to side play. Does it , or should I say did it in all gears, was more pronounced at low rpm's say from 2000-5000 rpm. neutral torque. ( no acceleration, or deceleration.