Originally Posted by supcom
This is not a good idea. The reason for two brakes is redundancy. If you have only a front brake, and the cable breaks or slips through the pinch bolt, you are in trouble.
V-brakes or disk brakes makes no difference. For safety reasons, you need two independent brake systems.
+1. If you want better braking, then replace the front v with a disc, and keep the back. Redundancy is good.
In addition, with only a front brake, it's possible to skid the front tire if you're heavily loaded, or on sketchy surfaces, which is a bad thing.