Right decided to go with dedicated trainer tyre. Just one question i'm looking at eventually getting a spare 700c wheel to save having to keep swapping tyres around. I can find a reasonable rear wheel compatible with a 9 speed shimano cassette. What i'm looking for is the rear cassette at a reasonable price. I have a Shimano HG-50, 9-speed, 11-30 cassette currently fitted on my main wheels. I'm a novice when it comes to replacing / changing cassette but was wondering if i could use any shimano 9 speed cassette without the need of adjusting derailor etc (so literally just swap out one rim for the the other) or will i need the same type cassette on the spare wheel?