Unicycle steel frame

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Hello all !

I choose to build a unicycle frame as a first project, I figured it would be easier and more forgiving (also I love unicycles).

I’m gonna build it around a 24” wheel that comes from another uni. I took inspiration from the said uni and frames I saw on the internet (special mention to Flansberrium and his fantastic work).

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I already started working on it, fork blades are 25x1,4mm straight gage tubes. I’ll ovalise them to weld the dropouts.

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PXL_20251017_0912184973472×4624 3.76 MB

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PXL_20251017_0912485623472×4624 3.83 MB

This week I machined the dropouts at work

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PXL_20260130_1336038413472×4624 2.35 MB

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PXL_20260206_1323201583472×4624 4.34 MB

PXL_20260206_160047077
PXL_20260206_1600470773472×4624 3.79 MB

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PXL_20260206_1940167723472×4624 2.74 MB

Added a big chamfer to clear the crank arms

I thought it was mild steel but after machining it I can say it’s not so mild

Next step will be machining the top plates, ovalize the end of the blades and get to welding.

I already tried to ovalize some scrap tubing with a vise but the result isn’t so pretty. I’ll try again with a 3d printed die

PXL_20251030_153420055
PXL_20251030_1534200553472×4624 1.38 MB

Until next time !

Paul

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Here’s my Unicycle. Made it a few years ago although rarely try to ride it. Andy

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P20901742976×3968 1.84 MB

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That’s a really nice uni ! Does this geometry add something to the ride or is it only cosmetic ?

And where did you get your dropouts ?

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Drop outs were bought along with hub from Affordable Unicycle for Commuting, Best Long Distance Unicycle . Design was a copy of hatchet styles and my own experience as a 50 year LBS veteran, like the two post binders. This is now a silver and black as a practice paint project as i move to auto grade paints and from Rustoleum cans. This is but another example of the odd stuff I have made over the years. The guy who first taught me frame making also made unicycles for the neighborhood kids (till one broke his arm on a giraffe), his personal uni used a 700C sew up that JUST barely cleared the crown’s underside. Andy.

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Sick! I like the dual crown design for a unicycle. Gives it some good DH bike vibes.

I’ve also been interested in building a 27.5" unicycle for myself for a while and since I know Jacob from Flansberrium from my unicycling background I asked about his dropouts. He was willing to sell to me. Maybe he is open for your project as well? :slight_smile:

Looking forward to see more of your project.

Have you done any FEA on tubing diameter etc? Curious for my own build how thin it’s possible to go.

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Thanks for the info, it didn’t occur to me that you could just buy them !

I love seeing odd stuff made by other people, it’s always inspiring

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That’s a good idea but I live in europe and shipping costs are quite expensive

I haven’t done any, it is surelly overbuilt but for a first frame I wanted to be safe. I asked Jakob and he told me he’s using tubes from .8 to 1,2mm thick depending on the use case. I’ll go with 5mm top plates, it should be sturdy enough for some light trial/small trips around town :slightly_smiling_face:

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Good point. And you have already machined a set, so sticking with those is probably your best option :slight_smile:

I’m also in Europe so I can let you know if I do buy a pair at some point.

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