Shortening 16" Unicycle

General
1

I just got a 16" unicycle for my 4 year old son, and he is still about 2" inseam too short to ride it even with the seat all the way down as low as it can go (with the seat post shortened obviously).

I was wondering if anyone has tried clipping the top 2" off of a frame to allow for a shorter unicycle. It is the red 16" trainer from UDC. I would try to saw out or dremel out or ??? a 1.5-2" cut in the back to allow the clamp to clamp.

If I did so, would the unicycle still be strong enough to support me? (170 pounds). I kind of like the seat lower, but I have not learned to idle and don’t know if it would be easy/possible to idle if the seat was as low as he is going to need it!

I kind of figured it would be too big, but thought if it did work out it would be a better unicycle long term. I’ll probably just order a 12" Sun and paint it… but I have this one here now and he is really mad I won’t “let” him ride it!

2

I’ve got a 16" jugglebug that’s too big for my son, and I am considering cutting it down a bit too. I don’t think it will weaken the frame at all to shorten the seat tube. My plan is to drill a hole where I want the slot to end, and to use a dremel to cut the slot to the hole.

3

Before cutting down the frame, check for how much tube you’ll have left after the cut. That is, on the inside. You’re measuring how much grip the seatpost will have in there. For a 4-year old it’ll probably be fine in any case. You could also try using shorter cranks to keep some frame length, but you’ll have to cut it anyway so that’s probably not worth it.

You want to lower the seat below where it can normally go, then try to idle on it? My knees hurt at the very thought! Not recommended. For comparison, I have a 12" unicycle on which I also cut down the frame a long time ago to make it shorter. I know what it’s like. :slight_smile:

4

Chop the top. It is pretty common with people getting a long neck frame and cutting it to the perfect length for them.

Not everyone drills a hole at the end of the slot but it is probably a good idea.

Edit: and listen to John

5

I just did that yesterday with a 20" uni for my 8 year old. He wanted a Muni. I bought a Trainer from UDC and a 20" knobby from a local store. I cut off approx 4" of the seat tube and 4" off the seat post. Drilled a hole where the cut would end and used the dremel to cut a slot. Worked perfectly.

6

I was just looking at that. I have it open in another tab, so here’s the link to your post on the subject, in fact!

It turned out really nice. I don’t think there are any issues cutting down unicycle frames if you are careful and do a neat job of it.

7

Thanks, I used a tubing cutter then a dremel stone wheel to get rid of the burrs.

8

Anyone tried clipping the top 2" off of a 36er frame for a shorter but 75kg adult? I always want to try a 36er but I guess my legs are not long enough (unless using 90mm cranks with a 36er).