ASK MBA: HOW DO I REPLACE A BROKEN SPOKE?

A common mechanical problem that's easy to fix

Measuring your spoke to the millimeter is important; this one is 266mm long.

Re-spoked

Q: Hey-o! So, I broke a spoke on my Hightower—just the i9 hub with aluminum rims. Do you know what kind of spokes they are? Can I just buy it online and replace it myself?
Brad Torbec
Sacramento, California

A: That’s a great question, because Industry Nine is known for the alloy spokes they customize for customers on their website, but it sounds like you’re talking about an OEM wheel with normal steel spokes. If that’s the case, they’re quite easy to replace, though it takes a little patience. You have a few options.

One way is to find the spoke that broke and figure out which side of the hub it attached to. This goes for any broken spoke on any wheel you need to replace. The next step is to take another spoke out of that same side and measure it. Spokes are measured to the millimeter, so you must be as accurate as you can be. The way to measure this is, if it’s a J-bend spoke like most are, start at the inside of the “J” and measure to the tip. Most 29er spokes will be in the 250mm–290mm range.

Another way is to use an online spoke calculator by simply plugging in your model rim, hub, spoke count and lacing pattern. The calculator will give you the correct-length spokes. Or, you can simply call the bike’s manufacturer and ask a customer service representative if they know your wheel’s spoke length. Some bike brands will have this information available but not all.

 

 

Once you’ve found the spoke length you need, it’s time to find a replacement. Your local bike shop is likely to have it in their stock of spokes, or you could go and order a bunch of them online. Usually, you can’t get less than 10 in a grouping, so it’s generally less wasteful and more cost-effective to buy only one or two at the shop. It also helps to bring the spoke you measured with you for a reference or gauge. While you’re at the shop, ask if they can dip the threads in a little spoke prep and make sure you’ve got a nipple with it. It’s possible that I9 used alloy nipples, but brass nipples are also good and may last longer.

Reinstalling the new spoke once you’ve got it is the hardest part of the whole process, but it’s not impossible with a little patience. This will require you to remove the rim tape at least in the area of the spoke hole you need. This process is much easier with an additional spoke to thread onto the top end of the nipple to hold it in place while you thread the replaced spoke on. It’s good to mark the replaced spoke with a tab of tape to indicate which one was replaced so you know what area of the wheel needs the most attention.

 

From there, it’s just a matter of bringing the spoke up to tension; this needs to be done with the other spoke you took out to measure also. If all goes well when you bring the spoke up to tension, the wheel will go straight automatically as it aligns with the other tensioned spokes, but sometimes this isn’t the case.

It’s helpful to own a truing stand, but our at-home truing remedy is attaching a zip-tie to the chainstay and working with the bike upside down so the end of the zip-tie acts as a gauge that points out irregularities in the rim’s trueness. At this point, it’s a matter of going back and forth tightening or loosening as needed until the rim no longer rubs on the zip-tie irregularly. When that’s done, all you have left to do is re-tape your rim and mount your tire.

 

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