Broken spokes?

If you’ve ridden bicycles long enough, you’ve probably encountered a broken spoke or 2. It happens, but why do spokes break?

In my experience over the past years as a wheel builder and repairer, the main cause of broken spokes is LOW SPOKE TENSION.
Low tension? Really? Yup.

Imagine a paperclip bent open. What happens if you bend and straighten the wire repeatedly? It breaks pretty soon, right? The same is true for spokes, which after all, are made from wire.

This kind of breakage is called “fatigue” and is the most common cause of random, non-crash-related spoke breakage. The problem is, normally, all of the spokes in the affected wheel become fatigued.

That’s the problem – what is the solution?  Proper, even spoke tension. This is critical if you’re looking for a reliable, responsive wheel.

Using butted spokes helps.

A butted or double-butted spoke has a thinner mid-section which is more “elastic” and less likely to fatigue, therefore less likely to break, compared to plain-gauge spokes. Don’t be fooled in thinking a “thicker” plain gauge spoke will result in a stronger wheel – it won’t. What it will do is reduce cost a bit, and add a bit of weight. I guess this is why we often see new mountain bikes costing over R30k being specified with wheels that are built using plain gauge spokes. Check out this forum discussion on the differences for some interesting points of view.

What do you do if you’ve broken a spoke?

Get some good advice from a trustworthy wheel builder. If you ask me, if you’ve broken more than 2 spokes in the same wheel, all of the spokes are fatigued and should be replaced, and the wheel rebuilt by a professional.

Chances are good, especially if you’re using “budget” wheels, that the rim is also buckled, perhaps beyond practical repair. If this is the case, the bike mechanic tasked with replacing the broken spoke will be able to get the rim to run true again, but the spoke tensions required to achieve this will be all over the place – some spokes will have a very high tension while some will be too low. It’s these spokes that have a too-low tension that will break again and again. If this is the case, it’s time to replace your rim.

Rim replacement is a great opportunity to upgrade your bike and get a rim or set of rims which are stronger, lighter and offer true tubeless capability. (More on tubeless here)

Have you broken spokes? Invest in quality spokes and have your wheels rebuilt. This will give you peace of mind and prevent a ride-ending mechanical due to broken spokes.