Riding with a broken spoke

[Rhodrich]

On my way to work yesterday, I heard a distinct twang from my rear wheel, and on pulling over, found that a spoke had broken in my rear wheel. Not being able to do anything about it there and then, I opened up the qr on the brakes, and carried on to work (and home again).

I thought that I'd be able to fix it yesterday evening, but unfortunately, I couldn't find a correct length spoke in my spares box - they are 306mm, which is about as long as it gets for a 700c wheel.

I've managed to find and order some online, but they're probably not going to get here until the weekend. I've bought a pack of 6, so I'll have some spares in stock in future!

My question is, will it damage my wheel to ride for a couple more days to and from work with the wheel in this state? (Total of about 75 miles). It's a 36 spoke 3 cross pattern, so the deformation from the lack of spoke is not too bad - there's no brake rubbing with the QR open. The wheels are Rigida Score rims laced to Shimano 600 Tricolor hubs with double butted stainless spokes.

Thanks.

[RichMoss]

I would say it will be fine, it would be worth checking spoke tensions to make sure that no individual spokes are carrying an excessive load (pluck and listen to the pitch of the note- higher pitch=higher tensions), and a little tweak with a spoke key if needed.

[Rhodrich]

Thanks. I'll risk it then. Here's hoping no permanent damage will be done......

[531colin]

Spokes fail from fatigue, not from a sudden peak load (unless run over by a bus, etc).
Any spoke that fails eg. as you pull away from the lights was already fatigued.
That being the case, I would slacken the 2 spokes adjacent to the broken one so the wheel is more true, re-set the brake Q/R and ride it until the spokes arrive.

[Brucey]

306mm? On 36h x3 700C...?

I don't believe it!

I have Rigida score 700C listed as 612 ERD which would give 295, 296mm spokes on a rear wheel. If built x4 you can get to 302/304mm.

cheers

[Rhodrich]

You're absolutely right Brucey - I've just checked, and it's x4, not x3. I have the spoke that's broken in front of me here, and there's no doubt it's a 306. Rear wheel, non drive side.

531Colin - that's a good idea with regards to slackening off the surrounding spokes. Thanks.

[Rhodrich]

Then again.... is a spoke measured to the inside, the centre, or the outside of the J bend? It's 306mm measured to the outside, but 304mm measured to the inside.

If I've ordered the wrong length spokes, will the extra 2mm cause problems?

[chocjohn9]

I would say that you will be fine too. I had a spoke break after about 20kms into an audax of 300kms. I carried on and I made it,without any further issues. It was 32 spoke, 3x.
(Apart from a nagging irritation in my head )

[Brucey]

Then again.... is a spoke measured to the inside, the centre, or the outside of the J bend? It's 306mm measured to the outside, but 304mm measured to the inside.

If I've ordered the wrong length spokes, will the extra 2mm cause problems?

I think you have ordered spokes that are too long; measuring to the inside of the bend is the conventional method.

You may need to shorten them to prevent the ends from going through the rim tape, and once you have done that the nipple may not screw all the way down without binding.

cheers

[JohnW]

Spokes fail from fatigue, not from a sudden peak load (unless run over by a bus, etc).
Any spoke that fails eg. as you pull away from the lights was already fatigued.
That being the case, I would slacken the 2 spokes adjacent to the broken one so the wheel is more true, re-set the brake Q/R and ride it until the spokes arrive.

You're a learned man Colin - many, many times more so than I am - but I have had a duff spoke, and it was quite new. Normally I wear rims out and never break a spoke, front or rear, but duff spokes happen.

[531colin]

John, I agree, duff spokes happen. But if you build a wheel with duff spokes, they don't all fail at once, they fail one at a time, through fatigue.... a "death of a thousand cuts". So even if the wheel is built with duff spokes, you are likely to get home using the trick I outlined above....note that I am slackening spokes, not tightening them......and the next spoke that fails can be in a different bit of the wheel.
(I have once had a duff batch that were too weak for me to be able to build a wheel with them.....they showed ductile failure (not fatigue) as I stress-relieved the wheels.)

[Rhodrich]

New (slightly too long) spoke put in over the weekend. The nipple did not bind, but the spoke does sit slightly proud of the nipple. Given the well that the nipple sits in on the rim, this isn't a problem, and it doesn't touch the rim tape.

So all good, except that my cycling with the rim in that state for a few days (with the two surrounding spokes loosened as per 531Colin's advice) appears to have turned the wheel slightly egg shaped. I've had flat spots before, after hitting potholes, but I've never seen areas of the rim that are noticeably higher than the others. The frame is fairly close clearance, and the SKS raceblades now rub on the tyre at that point when the wheel is spun round.

I've tightened the new spoke, and the ones either side, and this has improved things slightly, but not fixed it. I do hope I haven't wrecked the wheel

[JohnW]

In your position now Rhodrich, I'd do two things.

First is that I'd file down the protruding bit of spoke - you'd be amazed at what can put a hole in a tube after a while, when the pressure is in the tube.

Second is that I'd take the wheel to a wheelbuilder for him to solve the out-of-round feature. If it's that bad, then if nothing else you'll feel it when riding at any appreciable speed and the sound of the rubbing will eventually annoy you.

That's just me - that's just what I'd do - this is not an old git telling someone else what to do.

[MikeF]

I'd first check the ovality, if any, of the rim itself. You should be able to do this by spinning the wheel in the bike frame against some sort of marker on the frame or brake etc. If it is oval slightly, unless it's damaged, you should be able to true it, by slightly tightening/loosening a few spokes in the right place. If you're not confident then trip to the LBS. Is the tyre sitting on the rim properly and not causing the ovality?

[531colin]

Having ridden the wheel with 1 spoke broken and its 2 neighbours slackened off, is it a surprise that the wheel is out of round?
As above, take tyre off and check that the RIM is out of round, not just the tyre.
I would expect a "high spot" where you have had 3 spokes next to each other with reduced tension.....to level it out you need to wind the tension back onto those 3 spokes, and this can feel quite brutal....assuming it was a driveside spoke that failed, because the driveside are under greater tension you need to wind on roughly 0ne whole turn on a driveside spoke for half a turn on an NDS spoke.....so thats Two whole turns on your driveside spoke for one half turn on each of two NDS spokes......that might move the rim something like a millimeter, the spoke will stretch a bit too.
Its the number of turns to get an effect on radial trueness that confuses people who are used to seeing an effect on lateral trueness form the odd half turn.