Seems like a bad idea to me. Disc brakes put a lot stress on your front fork and disk forks are built to take it. Plus I think I'd rather have a good set of v-brakes than a no-name set of mechanical disk calipers. Plus the cheapo no-name hubs that the kit comes with. There are other kits out there that will allow you to run any disc caliper you want on the rear of your bike but it really isn't worth the investment IMO. My old spare bike is rocking a disk brake up front and v-brake in the rear for that reason.