John- I have seen the results of brakes loosening up and coming off a bike. All kinds of drama can occur as you might think. The front failures have usually allowed the front caliper to be pulled out of the fork (or break off if the center bolt breaks), reach the end of the cable and dangle about (while clipping the wheel's spokes, often with bad effect). In back the effects are less control loss inducing as the caliper is either forced into the frame (with the usual mounting position) and/or the caliper won't dangle as far down and into the spokes, with the cable being shorter.
I've seen the caliper center bolt nuts loosen up on both sides of the system, center bolts break completely, caliper arms break, cable fittings loosen and fall off the arms, cables break or slip (perhaps the most common with pads coming off), pads loosening up and falling off, canti pivot studs breaking off and the common coaster brake reaction arm strap (or nut and bolt) coming loose from the chain stay. All these make me convinced that a second brake system is a VERY good idea. As well as routine servicing (but then I'm biased towards keeping one's bike in good shape).
> VERY INTERESTING! How things we do by instinct everyday without a thought
> do demand a second look, Thanks everyone for all your input. NOW which way
> mounted is the safest IF the bloody nut falls off or the spindle snaps?
> This is something NO one has mentioned!
> Cheers John Crump OldgoingnutsBrit, Parker. Co USA
>
> _______________________________________________
Andrew R Stewart
Rochester, NY