Originally Posted by
63rickert
Yes axles will break simply from fatigue. More likely the dropouts are not parallel. Or there is a bit of slop in the cone adjustment and then the QR bends the axle a bit when clamped tight .These things will happen and they will happen more to those who are a little sloppy and to those with lower end bikes. If you had a late 70s basic Gitane or Nishiki you were not as fussy about dropout alignment or even aware of it and maybe it was a problem for those bikes, I don't know. My axles never broke before having 5000 or more miles and I was bigger than average. From some points of view 5000 miles is short service life. From other POV, 5000 miles doesn't even happen to any but a small sample of bikes. Right now I am too big and am running an FB QR axle that is 80 years old without problem. And yes I have done over 5000 on that ancient part.
That sounds about right, perhaps conservative. IIRC I'd get around 15,000 miles out of them before breaking, sometimes much more. The era of 6 speed 126 OLD coincided with my teenage years. Back then I rode about that mileage per year. I was always OCD about dropout alignment and stuff like that, and also fairly light on my bike. So, yeah, it wasn't a real problem, just an occasional annoyance. Practically speaking, an axle might break every year or two. Keep in mind that with this kind of mileage, I'd have gone through at 2-3 rims, at least a couple chains, oodles of tires, and probably a couple of freewheels in that time.