Originally Posted by
daka
I'm going to suggest you include the freewheel and chain in your investigation. The tooth shape on the freewheel and formation of the side plates of the chain links can make a noticeable difference in how well the sprocket picks up the shift.
Good idea!
If the chain is not stretched, I usually will not replace. That said these are older chains and freewheels lacking ramps, pins and all that newer tech. A good test will be to swap out to new chain and test and then swap out to newer freewheel and test. Thanks.