My 7-speed freewheel (13-21t) needs replacing as it is very worn, yet it won't come off the wheel (it's stuck, the bike shop could not get it off). Since the rear wheel is old, for tubular tyres, and has a missing spoke, I wouldn't mind replacing it anyway.
I am not sure which parts are compatible with which. The way I understand it is that I need a rear wheel compatible with a 7 speed cassette (I can switch to a cassette, if I get a new wheel?), and a 7 speed cassette. (Does it have to be 7 speed? or can I go 8-9-10 and just not use the outermost gears?) And if the new cassette has a bigger largest chainring, I need to make sure my derailleur can handle it.
My cranks are 2-speed 42-52t but I don't know if that's relevant.
Is my thinking here correct? Or am I overlooking something?