Originally Posted by
531phile
I'm just attracted to this setup for the pure novelty of it all. After seeing all these bikes with both disc brake mounts and V-brake mounts, it just made me wonder. If I were to do this, I'll do it on the rear, b/c locking up the front is dangerous. For the rear, I can deal with skids.
Novelty and aesthetics are your call. From a mechanical point of view, rdtomki has it right. It's difficult to balance the brakes so that each pulls to it optimum effect. Basically, you end up with two poorly functioning brakes. It's not a case of 1+1=2 with different brake systems. It's more like 1+1=0.25.
If you want more braking power, rider position has more of an effect on braking than does the type of brake you use. Sitting on the saddle in a 'normal' riding position results in a deceleration of 0.5 g. Moving your body back and down just a few centimeters results in a deceleration of 0.9g to 1.0g. In other words, moving back and down results in more effective braking.