I would check that the rims are in good condition. Maybe ten years ago my Araya rear rim (Miyata original '84) failed catastrophically... While braking down a fast hill the break pad stuck in a crack and ripped away maybe a foot of rim into a spiral of metal! This happened instantaneously, without warning, locking the back wheel up and sending me into a long dovetailed slide, but I didn't crash. Had this been the front wheel it would have been very very nasty... still makes me a bit nervous thinking about it.
Just a thought, those rims are 26 years old and maybe getting thin and have hairline cracks...
After this I got my first Mavic rim
