Cassettes - worth paying extra?
The constant grinding sound coming from my drivetrain tells me it's probably time for a new chain/cassette. I currently ride a 12-27T block, which I think is only available in Ultegra, but the price is horrific! 105/Tiagra seems to be about half the price (although only available up to 25T) - I'm just wondering what the difference is across the different levels? Presumably there's some weight differences, but am I likely to see a big difference in terms of longevity (which might make any cost savings somewhat of a false economy) or smoothness of gear changes (like there is with front sprockets)?