Eatadonut

I wrecked my truck coming home two nights ago, with my bike in the back. Somehow, a spoke was severed about 2 inches up from the elbow on my rear wheel. The wheel still spins true, so can I just replace the spoke and check the tension, or does this require a rebuild? I'm willing to do it if I have to, but it's an hour I'd rather spend riding.

TallRider

Given the circumstances of the break, I'd recommend you just rebuild with a new spoke.

If a spoke fails from fatigue, through normal stress cycles, then one spoke breaking may well be an indication that other spokes are close to breaking. It's usually a good rule of thumb to rebuild the wheel if you have two spokes that break from fatigue.

However, if a spoke breaks for some other reason, and the rim ain't damaged, it makes sense to replace the broken, as you have no reason to think that any of the other spokes are weakened.

Hoang

I would just change the broken spoke. I don't see why the whole wheel would need to be re-built.

TallRider

If you'd have read my post directly above yours (and posted quite long enough before yours that you'd have had to see it when you clicked on the thread) you'd have seen why oftentimes (though probably not in this case) a broken spoke means that the whole wheel should be rebuilt.

Rev.Chuck

Like Tim I reccomend rebuild on the second spoke(fatigue) failure. And that does not even apply to your situation, sounds like something must have struck the spoke just right, in the accident, to get a failure. One thing tho. Spoke failure anywhere except the threads or J-hook is pretty odd. I have seen a couple of wheels on newer bikes have failures similar to yours, where the spoke broke on its length. We would replace the broken one only to have another failure in a few days. Turns out there was a batch of bad stainless spokes that were flawed and would just,...break. So, stick a spoke in it and if you have a failure again, rebuild or replace the wheel. If it is a newer bike and you have another failure, take it back to the shop you got it from and have them check with the maker for reports of spontaenous failure.

DannoXYZ 

A break that far away from the ends is usually a forced-break beyond the ultimate-strength of the spoke. Something hit it, or someone stepped on it most likely. Line up the broken ends, do they match up perfectly with the spoke having parallel sides still? Or is the spoke stretched a little thin at the break point?

Could also have been a nick from the chain that caused a crack that spread.... Quick, call the CSI forensics team!

Oh, and check the spoke-tension on the other spokes, if they're loose, then fatigue-failure is definitely a possibility, and you'd need to rebuild the whole wheel anyway.

Eatadonut

I just figured out how it broke. I had it bungeed down in the back, and had one of the cords hooked to a spoke on the back wheel, I'm sure that's the one that broke.

These spokes have been on there for nigh on 3 years, so I'm sure they're not defective. The rest of the spokes are still tight, though of course I've screwed up the truing.

Bobby Lex

Bad move.

If this is your usual technique for securing your bike in the back of your truck you could be randomly damaging spokes, which could fail at any time.

Time to figure out a different way to tie down your bike.

Bob

lrzipris

Hey, Tim, why so defensive? Sounds to me as if Hoang offered the same advice [I]in this particular case[I] that you did.

TallRider

Good question. It wasn't defensiveness, just annoyance. Basically, lots of people use message boards to kill time, throwing off flippant, poorly-thought-out and/or redundant responses. This is fine in many cases, but at a place like the mechanic's forum, where the purposes are to
a) answer people's questions, and resolve tricky issues
b) build searchable cumulative knowledge
such practices drag the forum down.

Anyway, Hoang's response, to the extent that it was any good, was redundant, which is fine if he's concurring and adding weight to the conclusion that someone had already posted. But Hoang's post gave no indication of engaging my post.
This alone wouldn't have been enough to annoy me, but his post in and of itself was also inaccurate and/or misleading, and of course, flippant. He implied that there's little reason that you'd rebuild a wheel after a broken spoke. When, in the post directly above, I had laid out typical reasons for spoke failure, and noted that if a spoke fails for typical reasons, there's good reason to expect other spokes are close to their fatigue limit as well, etc.
Basically, Hoang gave a poorly-thought-out response that was useless to the extent that it was worthwhile, was misleading on important information, and didn't engage a discussion that was already present.
(That said, I have nothing against him personally. He may be a great guy.)

TallRider

+1.
Very good point.

Eatadonut

It's not, actually. I have super-crappy bungee cords, and one of them snapped while I was trying to get it to grab the pedal spindle (which I'm pretty sure is a safe place to put a little pressure), so I fixed it the best I could.

I'd rather have a broken spoken than a shattered frame when the bike goes flying, so I'm gonna go ahead and guess I made the right move at the time.

TallRider

Well, apparently it's a better choice than what you could have done at the time, but it still a bad way to do it. I assume you've got newer cords now, and can grab the pedal spindle again?

Bobby Lex

I'll take your word for it that your only option at the time was to secure the bungie cord to a spoke. For future reference, though, there are several conventional systems for securing bikes in the back of pickup trucks that don't involve bungie cords at all.

Here's one for example:

https://www.performancebike.com/shop/...cfm?SKU=15284#


Bob

Eatadonut

That rack is $60.00, I hadn't made the choice to go out and buy $5 worth of bungee cords, do you really think that's on my to-do list? I'll probably eventually make a rack out of a 2x4 and some quick releases, but none of that will be done if my truck isn't fixed, or if it's totaled.

urbanknight

I didn't see this addressed. If he just replaces the one spoke, should he loosen and retension the entire wheel, or is it safe to just put that one spoke in, tension it, and check for trueness? If it were me, I'd loosen all of the spokes a tad and retrue the entire wheel, but that might be overdoing it. What do you think?

becnal

When you guys say rebuild the wheel, does mean replacing every single spoke?

robthebiker

no!!!!!, just replace the spoke....take the wheel ooff your bike and take it to your local bicycle repair shop and ask them what size spokes you will need...you can buy spokes seperately.
robthebiker