So, you’ve noticed that one of your bike spokes is looser than the others, and now you’re wondering—how do you even fix that? Well, you’re going to need a spoke wrench, and there really aren’t any alternatives. (Luckily, they’re very affordable.) It’s the kind of unremarkable, yet incredibly handy bike tool that you might not think about owning until the occasion arises.
But you should know that spoke wrenches come in many different sizes, though some are far more common than others. Read on to learn more about how to use a spoke wrench and which size spoke wrench you’ll need.
What is a spoke wrench used for?
A bicycle spoke wrench is used to adjust wheel spokes in order to “true” a wheel—that is, put it back into alignment. It’s also used when installing a new spoke. Each spoke is secured to the wheel rim by a spoke nipple, which can be turned to either tighten or loosen the spoke’s tension. Ideally, you want every spoke tensioned equally and in a way that keeps the wheel trued and not warped. (Note: If you’re tightening one spoke, check the opposing spoke directly across from it. You might need to loosen it a half-turn so as to not over-tension the rim.)
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What size spoke wrench do I need?
Spoke wrenches are sized in millimeters (mm), though you may come across sizing by gauge. Most spoke nipples are external and easily accessible, but some manufacturers do make internal nipples that can only be accessed by removing the tire and any rim tape.
The most common spoke nipple sizes are 3.23mm, 3.30mm, and 3.45mm. However, you might encounter other spoke nipple sizes ranging anywhere from 3.2mm to 9mm.
Many spoke nipples are also square-shaped, including the most common sizes listed above. Some manufacturers use star-shaped or hex-shaped spoke nipples instead.
Though not as common, some wheels come with spoke nipples in two different sizes; one size is used on the rim, while a different size is used on the other end of the spoke at the hub. Park Tool makes a series of double-ended spoke wrenches for those particular wheels.
Unless you know the exact size spoke wrench you need, or unless the spoke nipples are star- or hex-shaped, you can get a three-way spoke wrench that fits the three most common sizes (3.23mm, 3.30mm, and 3.45mm) like the Park Tool SW-7.2 triple spoke wrench. Some multitools, like the crankbrothers M19 multitool, also come with spoke wrenches built-in, so check yours to see if that’s the case.
If you’re still unsure of which size wrench you need, you can try measuring the spoke nipple with an accurate tool like a caliper, or you can contact (or look up info provided by) the wheel’s manufacturer.
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Which way do I turn a spoke wrench?
Tightening an external spoke nipple, again the most common type, depends on your perspective. The old “righty-tighty, lefty-loosey” trick won’t apply here when looking down at the rim and spoke nipple (like in the images below). To tighten the spoke, turn the spoke wrench counterclockwise. To loosen it, turn it clockwise. (The “righty-tighty” trick does apply if you’re positioned outside of the wheel with the spoke end pointing directly towards you.)
Meanwhile, internal spoke nipples follow the standard rule of clockwise to tighten and counterclockwise to loosen (righty-tighty, lefty-loosey), when looking down at the spoke nipple.
Are there any alternatives to a spoke wrench?
Though you might be tempted to use a different tool like an adjustable wrench or needle-nose pliers (or some kind of homemade rig) in a pinch, you’re more likely to round off and damage the spoke nipple than fix your original problem. Spoke wrenches are very affordable, often selling for $10 or less, and are designed to do the job well—there’s no good reason not to use one.
What else will I need besides a spoke wrench?
If your wheels have bladed spokes, which are identifiable by their flat instead of rounded shape, you’ll need an additional tool like Park Tool’s bladed spoke holder to hold them in place while you adjust their tension. Otherwise, the right spoke wrench on its own can get the job done.
But there are some optional tools that you might find helpful, like a wheel truing stand or a spoke tension meter. Check out our guide on how to true a bike wheel to learn more.
When she’s not out riding her mountain bike, Jessica is an editor for Popular Mechanics. She was previously an editor for Bicycling magazine.
