Hi guys, I would like to tell you something I've learned from an old farmer, and that is "don't NEVER put all yer eggs in one basket!". Up till now I've not heard of an accident, but figure this, you break that lever, or injure that hand and you now have exactly NO brakes.
I don't like the geometry of Mountain Bikes, in part because I have no interest in looking straight down at the front tire, when I should be driving 3-4 carlenghts (actually bike lenghts) in front of me.
When I did build a couple of mountain bikes I used the rotary clutch handle locking the clutch on left, front brake right lever, rear brake left lever. I still have some of those rotating clutch handles in stock! Then I changed the bars for "touring" or "cruiser" type, and the saddle to "Touring" now the MTB is pretty close to a hybrid type bike.
I will never build a bike, relying on only one lever to stop it. I have actually at times, considered putting a caliper, or other rim pull brake, on coaster bikes just as an extra saftey measure.
Mike