Originally Posted by
ljsense
op says both the cogs and the chain are new, and the same thing happened on a different cog set that had low mileage
Same cogs, different chain. It's a new wheel. NOS cogs. NEW. Did a couple modest rides with SRAM chain. Skipping on 3rd cog. That chain was a few months old, very modest mileage. Thus, the cogs maybe have 100 miles, but I'd guess less. That SRAM chain, maybe 500-600 miles. Darn near new.
But, I still traded that out for a Brand New fancy schmancy Wipperman chain. Same result.
I'm swapping around the cogs, but can't get out to test right now. (Duty bound.) Derailleur has been no problem on other wheels, mostly 6s or 7s Freewheel equipped.
It's an odd one.