Singlespeed & Fixed Gear - Total Hub Failure

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View Full Version : Total Hub Failure


Ya Tu Sabes
02-08-05, 08:53 AM
Has this ever happened to any of you? I had been riding my ss last week when the snow wasn't so well plowed, and one day, just as I was getting home, the back wheel started to feel pretty wobbly. I didn't really worry about it right then, and just took the thing down to the basement to work on later, figuring it needed to be trued. So last night I went down and grabbed the spoke wrench, only to discover that a section of the flange of the hub where the spokes connect had just broken clean off. Ouch! How does stuff like this happen, and how did I not notice it immediately?


pgringo69
02-08-05, 09:01 AM
what make/model hub was it? what lace pattern? how many spoke holes?

ofofhy
02-08-05, 09:11 AM
Could have been a manufacturing flaw.


Ya Tu Sabes
02-08-05, 09:12 AM
what make/model hub was it? what lace pattern? how many spoke holes?

Mmmm. A good question to which I don't know the answer because I had it for a long time, having used it some time ago then put it aside for a while, then recently built up a new ss. I am at work now, but will investigate this evening (although I'm pretty sure it's a 32-hole hub laced 3-cross).

bostontrevor
02-08-05, 09:22 AM
Did you leave it in the old wheel or rebuild it as a new one? If you relaced it to a new rim but changed up the spoke pattern, the old spoke indentations create stress risers that can cause hub failure.

Ya Tu Sabes
02-08-05, 10:34 AM
Did you leave it in the old wheel or rebuild it as a new one? If you relaced it to a new rim but changed up the spoke pattern, the old spoke indentations create stress risers that can cause hub failure.


No, no, I've never done anything to this wheel except a minor redish, which is something I've done lots of times without these results. Of course, I didn't get the wheel new, so I can't say what horrors it may have been exposed to before finding its way to my loving hands.

powers2b
02-08-05, 10:39 AM
Fatigue failure.
It happens.
Can be accelerated by loose spokes.
Make sure wheels are properly tensionsed after re-dishing.
Enjoy

bostontrevor
02-08-05, 10:49 AM
Actually, correct me if I'm wrong, but spoke tension can't be proper after a redish, right? I mean a dished wheel is built with different length spokes DS and NDS so that they can be brought up to uniform tension, right? So redishing means that the tension is already going to be wacky, no?

supcom
02-08-05, 10:54 AM
Unless you have a symmetric hub (flip/flop), the drive side spokes will be higher tension than the non-drive side spokes.

bostontrevor
02-08-05, 11:08 AM
I'll be damned. I just checked Barnett's and you're right. I've only ever built flip-flops, so I just ass-u-me'd that the tension would be similar DS and NDS. I'm quite wrong. My bad.

Ya Tu Sabes
02-08-05, 11:55 AM
Yeah - this wheel at one point had more speeds, so the redishing naturally played with it a little bit. I've found that redished wheels tend to need truing more often. But I've never had one just totally crap out. Oh well. At least I got it for free, and it didn't happen while I was going very fast between two buses or something, and I have another bike so I can still get from here to there.

bostontrevor
02-08-05, 12:18 PM
Employing my newfound (some might say, embarassingly fundamental) knowledge, I would think you might have better results with trueness if you stress relieved the NDS spokes once you bring them up to tension.

But I've been wrong before. Like just a few posts back, in case you'd forgotten.

Martin O
02-08-05, 12:35 PM
For some years ago we had the same problem in south Sweden. Lot of front wheels the hub flange broke. It was a maillard/sachs hub. Later we recognise it was a geographic local problem. They had made changes in the road salt composition to save the trees :mad:

Ya Tu Sabes
02-08-05, 01:47 PM
For some years ago we had the same problem in south Sweden. Lot of front wheels the hub flange broke. It was a maillard/sachs hub. Later we recognise it was a geographic local problem. They had made changes in the road salt composition to save the trees :mad:

Stupid trees.

Although this did occur shortly after a week of heavy, snowy riding during which the bike was undoubtedly exposed to massive amounts of salt and other anti-snow-and-ice chemicals. But could that stuff be so noxious as to cause such thorough corrosion so quickly?

wasted weasel
02-08-05, 03:57 PM
Stupid trees.

Although this did occur shortly after a week of heavy, snowy riding during which the bike was undoubtedly exposed to massive amounts of salt and other anti-snow-and-ice chemicals. But could that stuff be so noxious as to cause such thorough corrosion so quickly?
I hope not, my bike has been sitting for several weeks now with a dried on crusted layer of road salt/grime....
I would say metal fatigue... old wheel, uncertain past... also if it turns out to be say a 36 hold hub... more holes = less strength. Every bit of impact force is transfered directly through the spokes....it's pretty amazing the abuse wheels can take when you think about it.....