Holy Grail of Suspension unicycles. HA! EUREKA!

EUREKA!!! I finally did it! I think ive created the plans that would accomplish it! I spent nearly 2 hours drawing these up. Their pretty sketchy… But it gets the point across, the 2 pictures are supposed to be connected to eachother where it says, like overlapped. And all berrings in the picture would have berring housings on them, from a unicycle frame or otherwise, so i wouldnt damage the berrings by welding on them, well, here it is!

everything would essentially have a enclosure, like plastic or something, I might vacum press some plastic parts for just the outside, Its what ive created, i plan to start building it soon

no, see, essentially the piston wont be moving too much, maybe like 3 inches

thats still a lot of clearence for a uni…

but still, how many things have you saw there the pedals are still suspensioned?

Add a DAKOROMAN DRIVE SYSTEM and you’ll be on to something.

I was thinking this the same day you posted your idea. Thats weird.

Anyways, ill probably buy a cheap nimbus muni frame and see what I can do.

Anyone know of some good shocks that are small but can be pretty stiff?

well, i think i did an exceptional job, im going to start building it after school this year, and show you all what im capable of. and my gear system isnt to have gear ratios, its just for suspension

why do you need suspension so bad anyway?

Im going to use little pistons off some scooters and snowmobeiles. Im gonna get all my other stuff from bikes, and the tire/hub off my old uni

its the point that it hasnt really been done before, trying to break new ground

Cause its fun, and its something new to try. Its not something bad to go for or think about. Theres no reason to be upity.

I have all the resources to build one, and im willing to build one soon… Im sooo excited:D :smiley: :smiley: :smiley: :smiley: :smiley:

if anyone finds anything wrong with my plans, please tell me, because i want this thing to be flawless

What exactly are these “pistons” you’re showing all over your designs?

It appears you’re using them in places where a spring would be more appropriate.

Keep in mind, also, that most pistons operate via the flow of a gas or fluid. This means they’ll act (or react) much slower than a spring would. Also, in many cases, a spring is much lighter than a piston of comparable size.

Looking at your design, you’ve got pistons damping the action between the wheel and frame, and another piston tensioning the chain. What would happen if the suspension piston acted faster than the tension piston? Your chain would slip or break.

Before you start incorporating such complicated components as pistons in your design, perhaps you should first study them in isolation. What are they used for? How are they used? What limits must one consider when using the piston (such as strength)? How does one select an appropriate piston for a given application?

Springs are much simpler to understand and implement. Perhaps you should consider using springs in your first design, then add pistons once you understand the forces and reactions involved in your suspension system.

Another thought…

It looks like you’ve got four chains in your design. You should be able to get away with three… you’ll def. need one chain for each crank, but why two chains for the wheel?

Motorcycles, bicycles, and some giraffe unis all use one chain to connect the drive shaft to the wheel… why don’t you?

How about using a shaft instead of a chain to power the wheel. Check out Christini AWD, it seems like it would be a good option eliminating the need for the moving chain tensioner (and therefore some slop and many other problems). You would probably need to have the gears cut square instead of on an angle though so it can transfer power in both directions.

It might be easier to build a strong connection between the cranks and frame if you lowered them to just below the wheel axle. Or along side the leg of the frame if you don’t want them that low.

edit, forgot to add the link

Im bored in my drafting class so if you can send me a clear picture with all the dimensions on it I can prolly whip it up for you on Autocad. Check out my avatar it is my torker cx drawing that I did on autocad.

From the top down:

The single bearing holding the top cog shaft is going to be trouble. As you pedal you alternately apply force with your legs. This will strongly tension only one of the chains at a time. This unbalanced force will cause your long cog shaft to rock back and forth across the single bearing attached to the seat post tube. The cogs at this point are right by the bottoms of your thighs. Ouch.

I can’t tell if there are two frame pistons and two tensioning pistons but I think there are. Let’s replace the frame pistons with shock absorbers because that’s what you’re trying to do there. Each will have a spring (or compressed air chamber) and a damping mechanism of some sort to slow down its response and keep it from oscillating. It’s kind of important that you get this time constant right otherwise it will be hard as a brick or mushy as Jello. This really takes a bit of thought to get right. Maybe the shocks from the vehicles you describe will work, or maybe one of the parameters will be off two orders of magnitude.

The chain tensioning pistons (and this is where you are REALLY going to run into trouble) should be replaced with VERY, VERY, VERY strong springs. You want springs here because you need fast response to keep up with the constantly and rapidly changing chain tension. A piston (compressed air chamber) or any kind of added damping will slow this component down too much. The reason this is going to give you trouble is because you’re asking it to travel a large distance very quickly as you vary the chain tension from zero to HUGE.

I don’t see a good anchor for your split crank assembly. It looks as if the cranks are coming off of the thin walled tubing of the frame leg on the outside of that tube only. It’s difficult to see how they are to be attached but if they are only attached to the side of the frame and each crank axle has only one bearing then when you apply torque by pushing the pedal, that bearing is going to want to bind.

Sorry, that’s the way I see it. I hope you keep at it because it’s a cool project and concept. I would strongly recommend that you eliminate any dynamic chain tensioning scheme first.

Yes, i know the flaws like that. Thanks for telling me about the pistons, Its just the fact that i have access to pistons and shocks from snomobeiles, Im just trying to use what i have, I think my design is actually really simple, i mean, its not perfect, but ive got time to work it out i think. And the axel on the seatpost area, thats like a last minute thing i did, when i so it im going to have a braket on it actually. And the system i did it in was fashioning it like a double chain giraffe uni, that was my main inpiration. Its just a little to try and get everything to slide liek that, im going to start building it soon, just have a few parts to get. Thanks for your responses guys:D :smiley: :smiley: Im going to end up making a few more drafts of this, i’ll get some dimensions up and stuff. Its practically a short giraffe unicycle. Some of the things in it are simply genious from my brother and dad, like the berrings are going to be held with berring housings, like the enclosures on frames. It’s still experimental

Edit: Im going to probably make some enclosure for the whole setup also, That sketch is really poorly drawn, its not to scale totaly. Its gonna take some time still to work the kinks out. Im going to try and make everything as small as i can. My 1:1 gear racio is like it is because i dont feel like fiddling with things. I’ll sketch more up, taking 2 hours a drawing, it might take me some more time