Suspension Unicycle pictures

I built this about 10 years ago,… modified Amp F2 mountain bike fork, 26 in wheel and air seat. Works great!

Now I check and expect to see dozens of suspension designs, but Nothing!! I’m sure there’s something out there besides suspension seatposts. Can anyone give me some links??

Web unicycle 003.jpg

Web unicycle 004.jpg

That’s a really nice piece of work, but unfortunately there still has never been a production suspension unicycle. Several people have handmade their own designs, if you use the search functino you will no doubt find some threads with pictures of designs.

With your disign the only thing that is being suspended is the seat, so has no real advantage over a suspention seatpost. Most who ride really knarly terrain preffer a fat 3" tire. Those who do use a suspention seatpost usually just ride XC.

There was a thread recently where a guy made his own design of a full suspention uni (hub, frame).

There was a thread hear a while ago discussing all sorts of design possibilities, all having various drawbacks. The biggest being drive control, strength, excess weight, complexity and therefore cost.

There weren’t any suspension seatposts when I built this. Thinking back, it was 1992 which would make it 15 years old now!! I added the air seat a few years back. I believe this pre-dates the whole MUni trend?? Its only 2 inches travel but that’s more than most seatposts, and it does have a hydraulic shock. I’m just surprised there’s nothing better after 15 years.

There are lots of ideas and conceptual drawings, and even a few attempts to adapt mountain bike forks with all kinds of flexibility issues. I’m just looking for practical examples that have been built and really worked.

I can’t find, but have heard of another Amp fork and a cannondale headshock adaptation. The Amp fork was and probably still is the lightest mountain bike suspension fork. I still have a longer travel Amp F4 BLT with 4 inches of travel, but that may be too much?


I like your suspension

  1. the torque of a quick turn i.e. rotation frin the hips is taken up by some easily made links. 2) the links can be big!! 3) there are no sliding fits which can woller out with use. I hope you don’t mind if I copy it!!! I think you’ve got somthing. I don’t think most the replys you have got are from people who have ridden a suspended uni. I’ve made one but it’s linkages are down by the wheel which makes the cranks farther apart than normal although I’ve never noticed. You are right they (suspended uni s) are great!!!. Don’t listen to the nay sayers unless they have actually made one and even then a grain of salt. I like very much. It looks like it would be easier to make than mine and you can use “normal” forks, seat post, etc. (yes you have to modify) but no specialty welding (aluminum>>> TIG or a tractor feed on you wire feed) like mine and no really special machining like special bearing holders like mine. Like I say I hope you don’t mind me copying. COOOOL!!

This post seems to me the design of a working prototype made.

I think the big area of potential benefit would be downhill Muni, like what KH and the Santa Barbara guys do.

These drawbacks are what I think stoped any real development. and to have the nessesary strength it’d weigh like 25 lbs, even if you figured out the drive problems. The big challenge is the thousands of dollars and time it would take to develop a prototype.

These are the designs w/ what I think have the most potential.

(if the wind up problem can be fixed/made negligible as John Childs said in post 151)

Maybee one of the major uni manufacturers can team up w/ a MTB maker who has the testing equipment, experience and resources to develop one.

I don’t think so. The problem is the seat goes up and down but your feet don’t. So your seat height is all over the place. There is some preload when you sit on the seat as well, so that’s a factor in the overall picture. All you need to do is hit a big bump with your feet in the dead spot (vertical cranks) and you’ll bounce right off the seat. This was my experience the first time I rode the Downieville Downhill, on my suspension post MUni in 1999.

More likely, the best place for suspension is for road and XC riders, where the terrain isn’t so radical, but your time in the saddle is long, and taking any edge off the bumps is a good thing. I think a short-travel suspension would be great on my Coker!

Yes. So far, I don’t think I’ve seen any suspended-pedal designs that everyone agrees would work. Most either only compress in certain directions, or would have problems with windup, oscillation and other issues. Plus the complexity of the designs would make them pretty expensive even at the mass-production level.

Your frame (kayaker43) looks like an awesome design. Very compact! But again it only suspends the seat while the feet still have to move with the contours of the ground. Why go to such complexity when you can use a suspension post? Of course if it’s for the fun of designing that’s a fine purpose in itself. So is your design 10 years old or 15? You gave conflicting ages.

Daniel Hopkins built a Rock Shox unicycle about 10 years ago. With a gel seat it rode like a Rolls Royce. Later on he built one with a Cannondale Head Shock. Unfortunately I haven’t heard from him in years so I think he’s no longer into unicycling.

Back to the suspension post idea, the ones I’ve had success with all have height problems, which makes them troublesome for Cokering. These two posts have mechanisms that run all the way to the bottom, so they can’t be cut down:
Then there’s the Thudbuster which, like my older Uni-Pivot model, isn’t quite so long, but still has a minimum length to allow for the mechanism. We need a shorter one for the roadies!

This is not to rip on your work, which I think is excellent, but from the perspective of a downhill, VERY technical muni rider (that’s about all I do), I will say that I would not buy a suspension frame for my muni, nor would I use it were I given one. As John said, suspension for technical muni simply moves the seat, which gets to be very hard on the rider’s knees, and technical muni is already bad enough in that area. Furthermore, wheel placement and tire location are critical for navigating rock gardens such as those found in Tahoe and Santa Barbara, so any aspect of a frame that reduces the rigidty of the rider-wheel interface is negative.

To top things off, the suspension would be of absolutely no use for large drops, simply because if you are putting weight ont he seat, something has gone seriously, seriously wrong.

All that negative crap said, I agree with John that for XC muni and cokering, such a frame could be of great utility. I don’t ride coker muni, but I can see how such suspension would make fast, mildly bumpy singletrack such as some of Santa Cruz infinitely more fun. Then again, I think many offroad coker riders would put a wide flange spacing ISIS hub as a higher priority. Still, improvements are improvements.

Suspension MUni

I am very rarely on the seat when landing from a jump or drop. I consider anything under about 3" to 4" just a bump. My ankles, knees and waist do all the bending and act as my suspension. I would be terrified of loosing foot/pedal contact with a suspension seat. Loss of Foot/Pedal contact is usually the number one reason for UPDs when MUniing. There was once a computer generated picture of a MUni with Suspension Spokes! now that is be a GREAT idea! I am wondering if anyone could actually make it work. A flexible rim would be needed though.


Suspension MUni

I am very rarely on the seat when landing from a jump or drop. I consider anything under about 3" to 4" just a bump. My ankles, knees and waist do all the bending and act as my suspension. I would be terrified of loosing foot/pedal contact with a suspension seat. Loss of Foot/Pedal contact is usually the number one reason for UPDs when MUniing. There was once a computer generated picture of a MUni with Suspension Spokes! now that is be a GREAT idea! I am wondering if anyone could actually make it work. A flexible rim would be needed though.


wait… i think im getting something… its a link, a web link, its called…

Gah no it slipped away!

That is a very interesting suspension design for a unicycle. Probably one of the most functional and practical designs for unicycling. The linkage from the AMP forks is pretty stiff and strong. The linkages could be larger and stronger if necessary.

The major problem with reliability for the telescopic suspension seatposts is that they are not designed to take the rotational and lifting forces that unicycling puts on them. They wear out very quickly.

The Thudbuster suspension seatpost designs work better, but the linkages and pivots are still not strong enough for muni use. Eventually the linkage breaks.

Too bad that AMP Research is no longer making bicycles and suspension forks.

Your suspension unicycle looks like a very good adaptation of the AMP suspension fork design. Nice.

But suspension like that isn’t really something that is that important for muni. Other advancements in the strength of the unicycles has been much more important. It is much more important to address the strength issue of the equipment problem first. Now we have strong splined cranks and hubs. We have better frame designs and better seats. Things are good. We can probably afford to daydream about suspension designs now.

As for the usefulness of suspension like that. It is only going to be most practical and useful for XC style riding where speed is the goal on trails that favor speed (smoother XC style trails). A suspension like that will allow you to stay seated more which means you can ride faster. You can spin faster while seated than you can while hovering over the seat or standing on the pedals. If you can spin faster you go faster. That means more speed. Would be useful on XC racing 29ers and for Cokers where the rider is tall enough.

Sorry, I forgot to emphasize FULL suspention. All of the links I posted are FULLY suspended and not just the seat.

As to your comments and others, w/ a suspention seatpost I fully agree.

If someone had say, $50,000, the time, equipment, and expertise to design, manufacture, and test the muni I think all the problems could be worked out.

Wow,… it seemed like no one was interested and I check back a day later and see all this!

Just to clarify things. This was a production mountain bike fork made by Amp research. I didn’t design the fork itself,… I basicly made everything you see painted blue, and added bearing clamps to the bottom of the fork legs. It is extremely rigid with no slop and a nice suspension feel. It weighs 11 lbs. as you see it with mtb wheel and no fancy parts. I spared no expense on the custom air seat cover made from an old sock.

I just checked and my last mountain bike trophy says 1992 and I built this the last year I was racing,… so it really is 15 yrs old. I did a web search back then and there was zero information to work with. I had no ideas what type of riding it could be used for because this was before the whole MUni craze started. I suppose it would be best for XC use because it sure is a nice ride across a bumpy lawn or trail. Off road unicycling was just being talked about then and a radical design was to just use a fatter tire.

I suppose a seatpost shock would do the same thing, but I doubt if it could be as light, tight and durable. I bought this fork from a 230 lb guy who could stand his MTB up on the front wheel and bounce up and down in a parking lot. That means over 250 lbs of bike and rider were hammering that poor fork which was at about a 30 degree angle to the ground,… massive bending loads there. I was even more impressed because it was the lightest susp fork made and probably still is.

Even now it seems like a practical and elegent suspension for a unicycle that would sell well if produced today. I always meant to send a picture to Amp, but never did. I wonder if they were bought up by someone else? I also have a later version of this fork with 4 inches of travel and dual shocks

I’m not claiming to be the first or to invent anything,… I just built this because I had an old fork, it was easy to do and looked like fun…

John - the 3" Thudbuster needs 144 mm of clearance to the “rails”
Now they also make a 1.3" which needs 98 mm of clearance to the “rails”


I’m glad your Amp fork has lasted well and stayed in good shape. I went through several of those forks back in the mid-90s, each of which suffered from terrible slop in the pivots. I had better luck with Girvin forks, which were also pivot-based (rather than slider forks), and dreamed of building a muni frame from one of those. Unfortunately, I had neither skills nor equipment for modifying one!

I think the problem with all unicycle suspension designs so far though is that they are either seatpost only like yours, so no real use for offroad riding, or complex designs that are way less elegant and efficient than a fat tyre, and probably add more weight. Using a fat tyre is a great solution, a 3" tyre vs. a 2" tyre is a whole inch of really high performance very responsive suspension.


There’s no law saying you can’t have frame suspension and a fat tire? They both help:)