Gearing and chain tension advice
Hi new to bike building so some advice for my 1980's project please.
Got 48T / 36T chainrings, freewheel is 12 T - 17T and rear mech is a simplex SX 610 which seems to working ok. Chain tension is correct when on big chainring but way too slack when on small chainring. Is the rear mech not working as it should, have I positioned it incorrectly on the hanger, or is it not compatible with this gearing ? Advice please