Thanks for the input. Was wanting to change my cassette and cranks and the new set up would put me at 31t total capacity and the 5600 are only rated at 29. Do you think that I could get away with running a 31t set up on a 29t. The 5700 are rated up to 33t total capacity so I may have to switch.
Yes, you should get a new RD with 33T or higher wrap capacity. Other less-than-ideal options to make your current RD work include:
- Size the chain using the big/big + 1" method. You won't be able to use the inner chainring and smallest cogs or else the RD won't be able to take up the chain slack and the RD will fold into itself.
- Size the chain to work with the small/small combo. You will NOT be able to use the outer chainring and the largest cogs; attempting to do so could snap the too-short chain or cause other damage.
If it were a triple chainring setup, I'd be tempted to try the first option since there's little reason to use the inner chainring and the smaller cogs.
On a double setup, I'd do it right with the correct RD. I'd want to be able to use the inner chainring with the smallest cogs and though using the outer chainring with the largest cogs is not recommended, I'd want to be able to accidentally use it without causing damage.
Originally Posted by slopvehicle
Not wearing a helmet makes me more aware of my surroundings. I find myself anticipating the hardness of concrete 50 or 100 feet in front of me, it's almost a zen-like connection between my face and the pavement.
The setup I'm running is 7800 shifters, 5700 compact crank 50/34, 5700 Front & Rear Mechs & SRAM Apex 12-32 cassette; this is a new build, and have only done 2 test rides totaling about 40km, but shifting at the rear has been perfect so far, looking at putting in another few hundred km over the next few weeks, so that will bring out any issues
from looking at what you are doing, it's similar, the shifters don't really matter for the cassette ratio, as long as it is the right speed.