Originally Posted by
fusilierdan
I'm thinking of replacing the drivetrain on my giant tcr c2 2007.
It has 39/53 crank and a 12-27 cassette. I'm looking to improve my climbing gears.
The options are to put on a 12-30 cassette. To do so will require a new derailleur(shimano 6700 med cage) The chain and cassette will need to be replaced soon anyway. Or replace the chainrings to a 36/52. I'm not sure if that's possible.
The shop said option 1 would be about us$250. Would I gain enough for the expense? They seamed reluctant to explore the second option.
I could buy a new bike but that may not go over well with the CFO
If you are not racing, or competing, I'd suggest a 30-46 compact. 46 is good enough for most flats. It might be too slow if you want to speed up down hill, or ride in a slipstream of a truck going over 50 km/h, but apart from that, it's fast enough. The chain will run pretty straight in mostly used combos.
30 small ring allows a very good climbing gear, as well as mounting a tightly spaced cassette on the rear, without loosing climbing ability.