I purchased a 1970 Raleigh 10spd at a LBS in April. They changed the cassette to a 6 making it a 12spd.
On the last ride the chain started jamming between the derailleur and the large chain ring when shifting from the small chain-ring to large chain-ring. This morning I attempted (without good results) to adjust thing. This is a non-clicking old fashion shifting system. It had been working o.k.
Any thoughts on the problem?
Yeah, I would check two things right away, first of all is the derailleur square to the chainring, I've seen where the derailleur got whacked at some point and it was fine, but changing the freewheel or cassette to one with a different dimension, could cause it from being slightly off to far enough to give issues. Another thing is, the height of the derailleur, from the outside plate of the derailleur to the largest chain ring at the top should be no more then 2-3mm and this gap should be for most of the length, if it's more then this the chain might be jamming in between.