Broken Spoke
 

Today I was riding in the hills, and was gently going up-hill in 3rd gear or so and PING! one of my rear spokes broke off at the hub end.... is this normal? I had done about 50km of riding by this point and had gone over some rough patches that might have bent the rear rim, although the bend in it could be from after i broke a spoke....any ideas? i have 32 spoke wheels with Alex 22A rims.

Brendon
:beer:

yes, broken spokes happen. If your wheel is new, there is a chance that you may have done some damage and the broken spoke is a symptom of more to come.

If you have the skill, replace the spoke, true the wheel, and check to see if your rim is still round without any lumps.

Also, check the rim to make sure you didn't cause any flare-outs or other obvious damage.

make a mental note as to which side it was on (mine are always on the non-drivetrain side) it can help the LBS with a diagnosis or rebuild. i had a wheel that always popped during the same kind of ride you described. my LBS backed off the tension and did a retension and i haven't had a pop on that open pro for over 10,000 miles now.

what amazes me is that the last few broken spokes on my mtb haven't been when I was tearing down a rough downhill section etc. but on sedate rides on the road with the kids. I think it doesn't like going slow ;)

This summer I had the same problem that NZcyclist and skdsl are describing. My spokes were breaking at the hub flange nearly every ride even when I wasn't in a rough section of the trail. My wheel wouldn't go too out of true each time, so I could ride it back to the trailhead carefully. What ended up being the problem was that the factory wheels that came on the bike were of a low quality and weren't built correctly to begin with. The spokes were loose enough at the flange to allow a small amount of movement to occur at that spot. The spokes were also no-name to begin with. Eventually, the spokes started to snap along the hub from the repetive stresses on those spokes from riding the wheel with the problem, and I realized what the problem was. I bought a new handbuilt wheel from my LBS with quality components and haven't had a problem since. The problem only occurred on the non-drive side spokes of the rear wheel. It's at least worth checking the wheel to make sure it is spoked and tensioned properly.
-Moab

FWIW, slackening of non-drive side spokes is fairly easily dealt with by lacing that side closer to perpendicular than the drive side. Many rear wheels have 4x/3x or even 3x/radial spoking.

Nice to know I'm not the only one witht his problem. During my recent rear tire problems I discovered I'd been riding around with three spokes that had snapped off at the flange end. I guess three years of riding finally took it's toll...

I'll have to hit the local bike shop and see if they have replacements. Unfortunately it's one of those annoying places that closes at 6PM. :mad:

In my experience flange breaks have been due to poor quality spokes and/or improper building/truing. If I you start to see breaks around the threads expect more because fatigue is probably the culprit. Unless of course individual spokes have been tightened excessively to bring the wheel into true. I've seen some newbies try to true their wheels by tightening only. Too much tension in the wheel will cause spokes to break until the bulk of the stress is relived.

RunYun

If you've been riding around with 3 broken spokes, chances are that wheel is junk. If 2 of the spokes are close together, then the good spokes near them have probably overstressed the rim there, at the nipple holes. Also, having loose spoke ends could be pucturing your tube, too. FWIW, not climbing hills in a sufficiently low gear could also over-stress your spokes, causing them to fail prematurely.
Since you ride a low-end bike, anyway, chances are that your wheel a) was never properly tensioned, b) is not made of very durable materials, and c) isn't worth repairing, anyway. Toss it and buy a new wheel.

I was having this problem on the drive side and took the bike to my LBS. They just replaced the broken spokes and trued the wheel. Two weeks later I broke another one. Took it to a different shop. The mechanic there was a roadie/racer. Told me that there was not enough tension on the spokes. This allowed too much flex, thus increasing metal fatigue. He tensioned the spokes properly. This was less than a week ago, so I don't have long term results yet - but I rode it 51 miles on Sunday. No problems. It also feels like I get a "just noticable difference" when I accelerate from a dead stop - perhaps because it doesn't take that split second longer to take up the slack in the spokes. Good luck.

I suppose I probably should replace my whole wheel. I'm noticing a slide wobble while I ride...

As for the spokes, I just remembered I still have my old rear rim tucked away, the one that came with the bike. That thing was a real piece of junk. Had to replace it after about a year when it seazied up with a bent axelbar! The replacement was from a guy at work who had trashed a much better bike.

Hopefully the replacement spokes will hold while I start saving to buy a new wheel.

I see that some bike shops are still willing to take on jobs that they know nothing about. I suppose it is a result of machine built wheels selling in much greater proportion but their practices are still inexcusable.

For those of who with shops which clearly cannot be relied upon, I will suggest that you build the wheels yourself. A book I strongly recommend for anyone wishing to build functional, reliable wheels and/or understand their workings and failures is The Bicycle Wheel by Jobst Brandt. Of course you will seldom find this book at a LBS, especially one who builds poor wheels.

His thesis is that a vast majority of spoke breakage is due to lack of 'stress relieving'. See:

http://yarchive.net/bike/stress_relieve.html

When you have sucessfully built your first set of wheels, consider lending the book to the poor shop technician, who no doubt has never heard of it.

I havent riden my mountain bike in a few months, after buying a road bike and trainer, Im gung-ho for the spring. Today I bought new tires for the mountain bike. went to swap them, noticed I have a broken spoke nipple. wheel perfectly true. Had the wheels built a couple years ago by an excelent wheel builder. Im 240lb ride an FSR with hayes discs. The wheels are Mavic 517, wasnt expecting them to last, but they have taken tons of abuse. Im thinking maybe the spoke broke while the wheel was off in the back of my bronco. Checked the others, all fine (tight).

Just out of curiosity-was the nipple brass, or aluminium? Was it on the wheel with the disc?
Disc brakes increase lateral stresses on nipples. If you are building a wheel to use with discs, you should consider using stouter nipples than you would otherwise normally consider.

Even on my DH wheels, I use aluminum nipples. I'd rather have the nipple snap, than the spoke pull through my $80 rim!

L8R