[bhandziuk]

Locking your front wheel is usually 1) very difficult 2) non-recoverable unless you're good on a bike. If you lock you're front wheel going any speed over walking pace you'll probably go down. If you lock it up in the wet you're almost guaranteed to go down fast.

If you're riding uphill rear wheel drive on a bike is great because that's where you're weight is. The front wheel doens't have much. Put power into the front wheel and it might spin.

Put power through the front wheel while going downhill...well there was not need to because you don't need to have a power boost because you're going downhill.

I'm unconvinced except maybe deep snow with big fatty tires.