• Rear mech would probably work fine with 7 speed jockey wheels.

  • Prolly won't clear it at the points where it meets the chain guard or whatever is the name for the metal plate holding the jockey wheels to the rest. Would need new screws etc.
    I would recommend to go to local bike shop and buy used 6/7/8 speed derailleur for coffee money. They will have cheap chains too.

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