Originally Posted by
wunderkind
A good set of V-brakes is more than adequate.
If you ride through rain and mud. Then yes, disc brakes have an advantage. Actually I don't even know you need rear disc for a commuter. The front brakes handles most of the stopping. With a commuter that has rear discs, the rear rack choices are reduced significantly. Not to mention added weight.
There are zero rear-rack issues with chain-stay mounted disc calipers. The reason to run a disc on the back is the pile up of silt and such on the v-brake area, not to mention the rear-wheel is always the one with the braking surface wearing out first. That happens specifically because dirt piles up more readily on the rear v-brakes
The added weight is nothing, unless one is considering a pro-level race bike in comparison.