Square Taper Cranks and Alternatives

Square Taper Cranks and Alternatives

04/27/21

The crankset utilized by your preferred unicycle might very well not be something you think about very often. Unless you tinker with your build and really get into the gear and accessories you build, your unicycle’s crankset just might be something you take for granted.

Well, if you ever need to perform your own maintenance, repairs, or replacement in order to restore working functionality, it won’t be something you take for granted any longer. Just like the saddle and the rim of your ride, you rely on your crankset every time you go for a spin. It’s a vital piece of equipment that ties everything together.

Cranksets, like the rest of the components of a unicycle, are not all created equal. There are a few different classes of cranksets, with which you should be familiar in the event you ever do have to perform some maintenance on your one-wheeler.

Square Taper Cranks

Square taper cranks are also known as cotterless cranks and are very common, especially on affordable unicycles. They’re also pretty easy to identify and can be easy to work with as well.

These types of cranks can be known by the cross-section of the hub axle, which is, unsurprisingly, a square. This corresponds to a similar cross-sectionally square portion of the crank that fits into it. The cranks themselves are forced into the axle which creates a friction fit; the crank arms must then be secured with a nut or bolt.

To remove square taper or cotterless cranks you will need a crank extractor. First, you must remove the dust cap or cover over the axle and unscrew the crank bolt that secures the crankset. Then, retract the central shaft of the crank extractor and screw it into the crank before pulling it out. Unscrew the extractor from the crankset to release it and repeat the process on the other side. To install them, reverse the process.

Square taper cranks are common in unicycles because they are easy and cost-effective to produce. They also provide a good interface between the hub axle and the crankset, as well as they are secured properly.

Because of the way the friction fit in the hub axle secures the crankset, you must take care never to ride a unicycle with even slightly loose cranksets. If you do, you could deform the corners of the interface and prevent the cranksets from ever fitting securely again.

To learn more about how to remove and install cranksets, please consult our FAQs on our Unicycle Maintenance page.

Splined Cranks

Cotterless cranks might be common, but they are not the only type of crankset used in the construction of modern unicycles. Splined cranks are also fairly common and have some advantages over square taper, A.K.A cotterless cranks.

Splined cranks have “teeth” that increase the surface area of the fit between the crankset and the hub axles, and appear somewhat like a star in cross-section. Because of this, they’re stronger than square taper cranks, but they also require a bit more care.

For one thing, the bolts on splined cranks need to be tightened periodically; for another, many splined crankset configurations are unique and not cross-compatible. This can complicate removal and replacement, but if you have questions about your crankset you can always reach out to us.

ISIS Cranks

ISIS (International Spline Interface Standard) cranks are a type of splined crankset and are considered the strongest available interface between cranks and the hub axle. ISIS cranks, like square taper cranks, have tapered axles, so their removal is similar. However, if you’re going to remove and replace your ISIS cranks, you need to use a crank extractor with an ISIS head, or else you will damage the threads.

The Tools and Resources You Need

Whether your favorite unicycle has a square taper spindle and takes cotterless cranks or takes an ISIS crankset, you need the right tools for the job in order to facilitate crank removal and installation.

Here at Unicycle.com, we carry crank pullers, crank removal tools, and other multitools (like torque wrenches, screwdrivers, and allen keys) along with bolts and other hardware that you might need to repair, replace or adjust your cranksets. We even sell the cranks themselves, as well as pedals, so if you’re looking to customize your crank length to your personal dimensions, we have everything you could need to complete the job.

Get in Touch with Us

If you have any questions about the type of crankset a given unicycle takes, about compatibility, or even about removing or replacing a crankset, consult our resource center where you find frequently asked questions. There’s a good chance someone else has asked it before and we have an answer for it already on our site.

If not, get in touch with us directly and we’d be more than glad to assist you. You can reach us at 678-494-4962. Let us know what you’re looking for and we’ll help you get to the bottom of it!