Originally Posted by
inspclouseau
Thanks all for the replies. Answers to the above questions:
Not sure why the bike matters but its a Look 795 Blade RS.
I did get it brand new, but the shop I bought from is 2 hours away. I will be bringing to the local shop but would like an idea of what it is first.
I believe it is a long cage derailleur, the thing is huge, the cassette is 11-32, and its a full r8000 Ultegra groupset.
The wheels are Shimano RS 370. My regular wheels with my preferred cassette are at the manufacturer for a repair.
No workstand at home, but I can easily reproduce by picking the bike up, pedal forward a time or two and suddenly stop pedaling. Just tried this and it was on the middle cog.
To be more exact, i think its the backward motion when suddenly stopping to pedal that causes it.
This was part of the cause for the case that I saw. The owner had a very jerky stop to his sprint, and it caused the rear axle to flex slightly(and bind the freehub body). When I tested the bike with a smooth sprint, I didn't have the issue, but when I stopped sprinting the way the owner did, the chain would slap. He tried another wheelset, and the issue was gone.
When you lift the rear wheel, and slowly pedal backwards, does the wheel spin backwards?