I currently have a 13-34 7 speed Shimano Mega 7 Freewheel, and the
smallest cog is a bit worn. I also find the smallest (highest) cog a
bit low, leaving me spinning but not englaging on some downhills. If I
invest in a new 11-34 Shimano Megarange Frerewheel, will I have any
problems with the existing chain / front crankset?
Also, is it possible to change single cog wheels on such a freewheel,
rather than replacing the whole freewheel?