The worlds best unicycle seat

Ever :slight_smile:

I’ll write a review tomorrow once I’ve put a few more kms into it.

More pics on the AU Facebook page:

what do you do for foam? and how much?

ooooooh interesting, it is about time we got a choice in curvature without having to over pad the center of the saddle and cause more problems.

I would like something a little narrower as well


70g for that carbon you say (on FB)? Is that right? That’s much less than the normal CF bases which are something like 260g.

You could also trim the plastic rear bumper down to save a good 20g (dead easy with a hacksaw). I’ve had a bumper like this for years now and it does as good a job keeping scrapes off the carbon base.

There is a reason why uni saddles are heavier than bike ones (though they could still be closer) - they require a lot more structural strength for pulling on the handle on the front.



I used an old KH freeride foam (cut in half previously). The hardware (plates) was from a broken KH seat. I need to trim off some foam from the front. The seat base is almost completely flat, but the metal plate at the front and a little too much foam makes it stick up a bit.

Not absolutely sure. I used kitchen scales which aren’t the most accurate. But it is at least half the weight of the gemcrest bases. The gemcrest ones are made for trials and street, which makes them virtually indestructable, but you don’t need that for road.

Put it this way, the combined weight of my mountainbike handlebar (118g), stem (140g), seat (250g) is two thirds the weight of the KH Slim saddle. The handlebars are Titecs, WTB stem and an old Ti/kevlar seat.

The combined weight of my road bike handlebar (230g), stem 105g), seat (195g). I use Deda Newtons, Alpha Q prolite stem, and a San Marco seat. Add in bar tape and it is still comfortably lighter than a unicycle seat.

Since the carbin seat bases are made by hand, what would it take to have a couple different curvatures, say one that’s flat like your, one that is semi flat, and one that has the KH curvature.

I don’t know that I’d want a totally flat seat for muni, but I’d certainly like to tr on that has half as much curvature as the Gemcrest or KH.

Did you lay up the seat your self?

It’s easier to add curvature by carving the foam, than getting rid of curvature by filling in the curve with foam (as done with KH bases).

The bases were made by a friend, I contributed to some of the materials. The mold I think was the most time-consuming task.

Indeed - not at all straightforward to make different moulds.

Like Feisty I’m hoping it’s narrower than a standard base (and that us normal mortals might be able to get hold of one).

It is narrower than an unmodified KH seat, because normally the foam has a lip around it that sits over the base. With this seat, I used foam from an old shaved seat, but the top bit, without the lip, so it’s narrower. I taped some inner tube rubber on the sharp carbon edge so it doesn’t cut into the seat cover.

We’re calling it the “Flatfish NNC”. I’ll write a proper review on Adventure Unicyclist once I put a couple of hundred kms on it.

First proper ride on the seat today, it was amazing. I was expecting to fall off the front as there is no curve to wedge against your crotch, but that was not the case. All I felt was greater freedom of movement, better control, and no wedgie sensation. It supports the ischial tuberosities, which is exactly what you want.

I did my 32km training route today, with just regular shorts (I wanted to try it with no padding), and a standard 24"/125mm unicycle (high revs, low resistance), and I have no crotch soreness whatsoever.

I’m so happy :stuck_out_tongue:


Get in line buster!! :stuck_out_tongue:

Hmmm, I’m usually good with words, but ichthyal tuberosities would be fish and potatoes, right?:slight_smile:

I want one to!!
My vegetables hate the curvature of a normal seat.

I thought it was something you got from frequent ladies of the night :stuck_out_tongue:

I’m not sure I can convince my friend Pete to make huge amounts- they take a lot of time and effort. All I did was contribute some of the materials.

The idea of this seat is basically to test my theory that flat seats are better. Now I’m convinced.

The fact it is made of Carbon Fibre is a bonus, but I wasn’t after a carbon seat (I already have three), I was after a flat seat. If I hadn’t come across this, I was going to cut one out of metal. The seat pattern is more or less a KH Seat that has been flattened, so all you need is a flat one dimensional KH seat pattern that you can machine out from a flat sheet of, say aluminium.

The lip around the edges is probably not necessary (you can always use more foam if you want a thicker seat), but adds stiffness. Either weld it on, and/or use a reinforcement plate for stiffness. The most important bit to reinforce is the front end with the handle. You could even cut it out of plastic or wood, as long as you strengthen the front end.

The KH reinforcement plate (even though it’s curved) might work by drilling extra holes and cutting off the bent bit (because by flattening the seat, the distance between the seat plate and handle is less). I’m thinking of installing it when I use a KH T-bar, just for added strength.

It’s the bony bits of the pelvis that you sit on. But given the fact that I paid $60,000 to go through medical school, I refuse to call it the ‘sit bones’ like everyone else seems to.

It’s the bony bits of the pelvis that you sit on. But given the fact that I paid $60,000 to go through medical school, I refuse to call it the ‘sit bones’ like everyone else seems to.

Lend me the mould? Or even sell me a plug and I’ll make my own mould? My composite construction skills/facilities certainly aren’t comparable to what Pete has, but however much effort he puts in, we’re not talking about something all that complicated or difficult to make if you’re not so worried about the optimum strength to weight ratio, surely? Certainly more chance of me making a composite one given the mould than making one any other way!

I’d think about making a mould myself, but as you mention that’s the really hard bit. I suppose the question about that if it’s really just a flattened KH base is how hard is it to flatten an original KH base to use as a plug. I believe you have a “scrap” plastic KH base, Feisty, any thoughts on flattening it (by heating etc.) - or any chance of sending it to me to have a try at flattening and building my own if I decide I’ve got the time/skills required?

It is pretty heavy- I imagine it will be easier to make your own.

I donated an old KH seatbase, and I think Peter cut slots down the middle, then heated it up and bent it flat. The mold is modeled on this.

In terms of strength, it is a 10 layer base. You could strengthen it more by laying more layers of carbon fibre. Or perhaps put more layers in the front of the seat (the high stress points), and fewer layers at the back to save weight.

The other thing we talked about was putting screw in nuts (*like the new model KH seats) layered underneath the carbon, which let you screw an allen bolt into the base, instead of having bolts coming out the other way.

If I do have a go, it will probably be a sandwich of some sort - have got some structural foam here (well actually it’s foamboard with the card covering removed, but that’s actually much the same thing!) I’ve used to make stuff with before. Means I can cut down on the number of layers needed, given stiffness is roughly proportional to the square of the separation of your outer layers - 2 layers top and bottom, hence a total of 4 might be enough. It is surely strength we’re more bothered about than stiffness here though - a bit of vertical flex in the base probably isn’t a bad thing - hence I might also build using kevlar, which is stronger but less stiff than carbon. The main advantage of kevlar though is that I still have a decent stock I acquired from an ex-gf 20 odd years ago (her dad tested projectile protection, hence some of my stock has holes in!) making the project rather cheaper.

Of course the other advantage of making a sandwich might be that I can avoid using a mould altogether - cut the foam to shape and lay the fabric up straight on that. Which also means I can make it as narrow as I like. We’re not really bothered about perfection of the surface here after all. It also fits in quite well with the idea of using the nuts you suggest - I think the seat base ones are the same thread as used on clipless pedal cleats, in which case it’s easy enough to make some of those using shoe plates, which I have plenty of lying around. Though the difficult thing if going that way is making a good lip - I think you’re wrong about the necessity of that, has to make a huge difference to the stiffness, and hence strength of the base.

Shall have a ponder about how difficult this will be - and to think I haven’t even yet even tried pulling a seat apart to remodel the foam - though I do have enough composite experience not to be frightened by a project like this.

…actually that does bring me back to another thought, that whilst I’m stuck with the curve if I use a standard base, a lot of the issues I think I have with standard saddles could be solved just by remodelling the foam I think.

Can someone detail what is involved with buidling a CF base by hand, where to buy materials, and approximate cost, etc? It doesn’t sound difficult on the surface but I’ve never done it so expect there is a lot I’m not thinking of.