Nearly any unicycle seatpost will give you a range of about 100mm for adjustments. If it’s too short you can raise it, or if it’s too short you can lower it, by adjusting the seat post up and down through the frame and then securing it with an applicable unicycle or bike seatpost clamp.
If you’re too tall, you can always get a longer seatpost. If you’re too short, and you like the size of your unicycle’s wheel, before you go for a smaller wheel size, consider cutting down your seatpost instead so you can ride more comfortably.
However, even with this range, some seatposts are just too tall for some riders to adjust comfortably without making alterations. While you can’t add length to a unicycle seatpost, you can cut one down, and there are two ways you can do it.
Cutting Down a Unicycle Seatpost with a Hacksaw
One way to cut down a unicycle seatpost is with a hacksaw. First, you’ll need to measure how much you need to cut off. Be sure to be as conservative as possible with this estimate because you can always take more off the seatpost but you can’t add more back on.
After you’ve measured the length you want to cut off, make a mark on the seatpost using the teeth of the hacksaw with a quick stroke. You may want to use a guide as a hacksaw will tend to “wander” through metal, making it difficult to make a straight cut through.
After you’ve cut off the excess length from the seatpost, use a round file (a rattail file) to remove the burrs from the inner and outer edges of the seatpost.
Cutting Down a Unicycle Seatpost with a Pipe Cutter
You can also cut down a unicycle seatpost using a pipe cutter instead of a hacksaw. Your first step is still to measure, and the same logic applies – take off only as little as needed. You can always take more off later.
Mark the spot you want to cut. Tighten the blade of the pipe cutter till it meets your mark on the seatpost, then clamp it in place. Next, rotate the seatpost while firmly grasping the pipe cutter to prevent it from spiraling which can cause damage to the seatpost. With every revolution around the seatpost, tighten the blade.
Pipe cutters tend to produce fairly precise, burr-free cuts, but if there are any sharp edges you’d like to remove, use a round file in the manner described above.
Where Can I Get a Unicycle or Bike Seatpost Clamp?
Once the seat post is cut down to length, you’ll still be able to adjust it up and down for height, and to help secure it in place you’ll need a fitting unicycle or bike seatpost clamp. Seatpost clamps help secure your seatpost at the desired height, and there are two main designs, quick-release seatpost clamps and bolted seat clamps.
Unicycle.com has a wide range of unicycle and bike seatpost clamps in several sizes and configurations, compatible with many popular brands and styles of unicycles. Visit their collection via the link above or get in contact with their customer service team at 678-494-4962 for more information.