I have a Raleigh Scorpio 12-speed bike, which I'm wanting to get back on after about 14 years away from cycling (through laziness I'm ashamed to admit). I don't want to shell out for a new bike until I get fit, and then get something really nice. I had upgraded bits and pieces on the bike so it is now a complete hotchpotch. I changed the standard Shimano SIS rear mech for a Shimano 600 Ultegra unit, put 105 dual-caliper brakes on it, and also swapped the standard wheels (+cash) for a pair of really nice Mavic GP4 on some old but very smooth Shimano 600 hubs.
I want to change back to clincher type rims from the Mavic tubs, but I'm not keen on getting new rims built onto my old hubs as I reckon I could probably just buy new wheels for the same cost. I'm worried because it doesn't appear that you can get decent 6-speed hubs anymore, everyone seems to be doing 8/9/10 speed nowadays. So, my questions are:
- If I buy a new pair of wheels with an 8/9/10 speed cassette, will they fit my existing frame, or do I have to put '6-spd' hubs on it with a 6-speed cassette?
- What's the difference between a freewheel and a cassette?
- Do I have to buy wheels with a Shimano cassette, or could I use wheels with a Campagnolo (for instance) cassette where everything else in the 'drivetrain' is Shimano?
Any help gratefully appreciated!