So you’ve just bought a brand new unicycle that you thought would be perfect for you - only, you get up in the saddle, and something’s wrong. You can’t reach the pedal at its lowest point with your leg fully extended - or, just as bad, your knee is just past 90 degrees with the pedal all the way at the bottom of its rotation!
You guess it's time to get a new unicycle or go back to the drawing board - but not so fast, there are things to do to adjust the ergonomics of your one-wheeler, and some precautions you could have taken to have prevented this in the first place.
Let’s rewind a little and start from the beginning.
Step One: Get a Unicycle That Fits You!
While you can adjust a unicycle seatpost, get a new seatpost clamp, and even cut down the seatpost for a better fit, the first and most important thing you need to do is get a unicycle with a wheel that fits your dimensions in the first place.
By dimensions, we specifically mean your inseam measurement, which is the distance of the inside of your leg, to the ground. This measurement can be easily taken at home.
First, with your shoes on, straddle a thick textbook - sort of as if it were a bike or unicycle saddle. Then, using a measuring tape or stick, measure the distance from the ground to the top of the book - you can use this as a rough estimate of your inseam measurement.
It is the most important measurement you can use to find a unicycle that fits you best. You will find recommended inseam measurements listed on each product page - you can find them right in the specifications for each unicycle.
Because of the way unicycles are engineered, with the crank arms connected directly to the hub axle, the larger the wheel (and crank arms) the taller you need to be to ride them.
You can adjust seatpost height and cut down your seatpost, but you can’t get a 3-foot tall child to ride a 36-inch unicycle - nor will a six-foot-tall adult be able to ride a 12-inch unicycle - not comfortably, at least.
If you get a unicycle that fits you, here are two things you can do if you feel that it could afford you a better, more comfortable, more natural fit.
Step Two: Upgrade the Seatpost Clamp
Unicycles come with seatpost clamps attached to the top of the frame. Seatpost clamps are all capable of tightening or loosening around the seatpost tube. These clamps all operate through bolts (either one bolt or two) or quick-release seatpost clamps (also either one or two).
You can adjust the seatpost tube up and down within the frame to a certain degree using the seatpost clamps. Simply loosen the bolt or the quick-release clamp, slide the tube up or down, and retighten the clamp on the seatpost tube at the desired setting.
Your unicycle saddle should be adjusted to a height at which your knee is only very slightly bent (that is, your leg is nearly straight) when you are sitting in the saddle, upright, with the pedal at its lowest point.
Making quick adjustments to saddle height in the field is important for some riders, which is why we sell a wide range of replacement unicycle seatpost clamps. If your unicycle came with a bolted model, you can pick up a tool to make quick adjustments in the field or even replace it with a quick-adjust clamp, which will free you from the need to use a special tool.
Just make sure the clamp you choose is compatible with your unicycle - you can find this information on the unicycle and clamp product pages, and call us for help if you need additional information.
Step Three: Still Too Tall? Cut Down the Seatpost
If you lower your seatpost tube far enough, at a certain point, it will get in the way of the unicycle’s tire - in which case, you cannot make the adjustments by raising or lowering the seatpost through the frame and will have to adjust the seatpost tube itself.
If you are certain that your inseam measurements are accurate and the size of the unicycle itself is not to blame, then you may be able to cut down your seatpost instead. In fact, most unicycle seatposts are specifically designed so that riders can cut them down as needed.
To cut down a unicycle seatpost, you have two basic options. You can cut it with a hacksaw or use a pipe cutter.
If you are using a hacksaw to cut down a unicycle seatpost, first measure how much you want to cut off and be conservative because you can always cut off more but you can’t put more back on.
After you have marked the seatpost at the point you want to cut it down, start cutting and move slowly as hacksaws have a tendency to want to curve in the progress of their cut. When you’re done, use a round or curved file to remove any burrs along the edge of the seatpost.
If you’re using a pipe cutter, measure and mark the point at which you want to shorten the seatpost. Tighten the blade of the pipe cutter around your mark, then clamp it in place and rotate the seatpost. Hold the handle of the cutter steady or else the blade may want to spiral around the seatpost which will damage it. After each rotation, tighten the blade, and when finished, if the cutter has left any burrs, remove them with a file.
Seatposts and Seatpost Clamps Are Here at Unicycle.com
These three tips and techniques should make it possible for you to get a unicycle that fits you and adjust it to your specific dimensions for optimal comfort. We also sell seatposts and seatposts clamps in case you want to switch those out.
If you have any questions about how to choose a unicycle that will fit your inseam measurements, how to replace a seat post clamp or how to cut down a seat tube, please get in touch with us at 678-494-4962 and we’ll be happy to help.