A spoke is broken. What to do?

Published on 12.12.2022 from Anke Telle

Image by Daniel Kirsch on Pixabay

Reading time approx. 10 minutes

It happens. Suddenly you hear a clattering noise while driving. When you check it, you notice that a spoke is broken. What should you do?

Non-technical people see most everyday objects as black boxes. What else should you do if you have no idea about technology? So it should be mentioned here that a bicycle wheel is a fairly complex matter, even if it seems so familiar. 36 wires and a piece of bent aluminum profile support the weight of a person.

But we don't want to know all that today. So what do we do if we're out and about and a spoke breaks? We either remove it from the wheel (if that's possible) or we tie it to the wheel so that it doesn't get tangled and break even more. When we get home, we leave the bike alone for a while.

And what happens next? We should think about the connection between cause and effect. The latter is clear: the spoke is off. What is the cause? It is: the spoke is not loosely tensioned. It is usually quite tight. If it is not tightened enough or too much, it can break.

What is the reason for this? It is a so-called figure of eight. This means that the spokes are not evenly tensioned or the rim is bent because we crashed over a high curb. So it doesn't help much if you just buy one spoke and just put it back in somehow.

So how do you go about it? Either do it yourself or have someone else do it. If you're interested or fairly fearless, do it yourself. But it's not easy and it can go wrong. If you know it's beyond your capabilities, have someone else do it.

Why is it that it cannot be repaired easily? This is why: If the rim is badly bent, a repair will not help. You can straighten a bent rim using the spokes to a certain extent, but the forces in the spokes are very different and so great that the spokes will break again. And as a layperson, you have little idea of this. Often, even an expert cannot do this.

So you want to do it yourself? Here's how: Remove the wheel. Remove the tire, tube and rim tape. Rim tape is the plastic or rubber band that lies on the rim under the tube. This prevents the spoke heads or the so-called nipples (these are the screws that hold the spokes) from damaging the tube.

If it's the rear wheel with a derailleur, you also have to remove the cassette (the rear sprockets), otherwise you won't be able to put a new spoke in there. You'll need a special key for that. And something else about the rear wheel to make it even more difficult: With derailleurs, the spokes on the right and left are different lengths. On the side with the cassette, they're shorter so there's still room for the cassette. On the other side, they're longer. Got it?

You still want to do it yourself? OK, then it goes like this: You need new spokes. The dealer will sell them to you or you can order some. Remove an intact spoke and measure it. Do not measure the entire length - that would be wrong. Put the ruler on the inside of the bend in the spoke and measure backwards to the end. Measuring a broken spoke usually leads to errors. Before ordering, check whether other spokes are damaged or bent. It is better to replace several spokes.

At this point, I'm only addressing the intrepid DIYer. So you have the new spoke? Then you need a spoke wrench (or nipple wrench) to tighten the spoke. You can get one at Bauhaus for €2.95, at Toom for €2.99 and at Hagebaumarkt for €7.49.

This is what a spoke wrench looks like (Image copyright Hagebaumarkt) This is what a spoke wrench looks like (Image rights: Hagebaumarkt)

Insert the spoke the right way round and screw the nipple loosely on. The right way round means that you have to find out by comparing it with the spokes before it whether the spoke needs to be bent outwards or inwards at this point. See.

Various spoke nipples (Image copyright cloverleaf spokes) Various spoke nubs (Image rights: Kleeblatt-Speichen)

Now let's make some music. Seriously. You've probably plucked a guitar string before. It makes a bong or a bing sound, depending on how tight it is. We want to use this effect to check whether the spokes are evenly tensioned.

Too much tension is bad, too little is bad too. The spoke should make a bing sound, a higher pitched tone, not a bong, that is too little. You lay the wheel on your thighs in front of you and start plucking the spokes. Try to give all the spokes the same sound. If the rim is not bent, the wheel will run straight.

The dealer has some tools that you unfortunately don't have. But if you've already got this far, you won't want to give up. So: put the wheel back on the bike. If the wheel runs straight, then great. If not, then carry on as before. Use the rim brake as an adjustment aid. Clamp the brake with a cable tie, for example, so that it just drags slightly on the wheel. If you now turn the wheel, you can gradually turn the spoke nipples until the wheel runs fairly straight. Done.

Cost comparison:

Have it done at a specialist retailer: