Hey everyone! I found out how it would be possible make a shocked wheel unicycle that would never have ANY play when you pedal it! I don’t think I can make cool renders to show it off, but here is a blue print type thingy:
Looks good, but one of the only problems is that the seat moves when the shocks compress.
If I’m reading it correctly, it looks like the seat doesn’t move when the shocks compress. The pedals go down but the seat stays at the same height. Ouch. Having the pedals suspended is great for low seat or seat-out riding, but if the seat doesn’t go down when the pedals do, it won’t be real useful for cruising.
Kewl!! But youd need hinges in da middle or the rim would crack in half.But i wish i knew how to do dat kind of shtuff.
My sense of it is that the suspension will never really work if it’s rigged in the wheel. However if you took the idea of a suspension seat post (which have never really worked that well) and applied it to the frame (meaning the down tubes of the frame could somehow telescope up and down a few inches when shock loaded), you might have something. I suppose the Muni frame would then resemble (somewhat) the front end of a motorcycle with telescopic forks.
JL
Vanished and John Foss: The seat wouldn’t move when the shocks go down, but if the cranks were to be pushed forword it would, so you are both half right.
Musketman: Why? The shocks aren’t connected to the rim, exept for the tiny gear that turns the wheel. I guess a wheel without spokes would die easily if thats what you mean.
VivaLargo: If you think about it, having a suspension seatpost and a suspension frame would both have the same end result, that it would obsorb shock on your butt, but your cranks would still bend or break if you landed on them. I agree that it probably wouldn’t work, but its still fun to think of and design
cool Idea, but it would have quite a bit of play at the cranks, because of the gears, and because it looks like the rod that drives it might want to twist. I think the benefit from having suspension would be greatly outweighed by the play at the cranks, the added weight, weak rim, possible gear slipping, and lack of lateral stability.
a problem i see with a suspension wheel is that when you do a rolling hop, or roll out of a drop, the forces are forward and down. this means that if it flexes downwards and possibly forwards, it will affect how you can roll out of the drop, maybe even causing the pedal to hit the ground. just a thought.
in the mid 90s, Head Shock an extension of cannondale, came out with something called ELO which would lock out the suspension on xc bikes when activated. this would be used for climbing when you didn’t want your pedal forces to be absorbed into the suspension.
If a suspension wheel where created for a unicycle, this would probably be an important addition. you wouldn’t wand the suspension to be active while climbing, your force would push the axle downhill creating a larger o.d. on the wheel when you would want it to be smaller.
You would also want the suspension locked for jumping. shocks are designed to absorb energy not create it (springs) they would take height away from your jumping. if they where damped to be springy, you would get bucked trying to land a large drop.
depending on how supple the suspension is, you might want the suspension to be locked out on smooth sections just to make pedaling more efficient.
Why not just make a wheel with titanium spokes. They are really flexy. It’d also be light and simple.
I still think it’s worth asking the question of why we are so interested in making shocks for uni’s. It’s an interesting mechanical engineering problem, and fun to think about, but none of this is ever going to be practical. The pokes of a wheel weigh around 2lbs, max. It’s impossible to make any of this stuff that light bust still strong.
If you really want good shock absorbtion, you could simply make a really thick tire. I think mechanical apparatuses are inherently too complicated to work in reality.
As for yoggy’s idea for a shocked wheel, it’s nice and interesting, but I still have a bunch of issues with it. I’ve drawn plans for a similar wheel with 6 “spokes”, but I gave up on them when I really looked into it. The pedals will move whenever the shock engages, unless you can design something into the drivetrain to compensate for this. It took years in the MTB industry to solve this problem.
Re: Suspension MUni
Where are the spokes? You don’t need them to drive the wheel, but they
are still required to add strength to the rim. Can there be a “dummy”
hub only for connecting spokes to?
Hey, it would be easy to gear this design up or down. Just choose a
different size pinion. Or am I mistaken?
Klaas Bil - Newsgroup Addict
people who unicycle are shyly exhibitionistic - GILD
The shocks can’t be attached to the hub rigidly…when the shock compresses the angle between the shocks would have to change.
I’ve been coming up with ideas of my own for a design project for one of my Engineering courses and stumbled upon this thread. I have actually come up with a few rough drafts of what most everyone else has thought of too. I’m still fairly certain that it’s not very practical to make suspension inside a wheel, not for this application.
Pete, what program are you using? If that’s been asked, sorry for asking again. Right now I’m learning AutoCad, but only in 2-D, so whatever design I finally come up with will just be orthographic views. The pictures you’ve come up with are very impressive though.
There is an easy way to keep it as a parallelogram without using gearing. Think of two hydraulic cylinders with the top and bottom inputs crossed. There is a problem of different flow rates, but this would be solved by using four cylinders of two sizes.
(excuse the crappy drawing, my solid works is not installed)
Way to go on the parallelogram idea. (maybe a 3 parallelogram design with three shocks?) I love the idea of adding a free hanging spoke tension loop to keep the rim true.
Parallelogram module
If you did the parallelogram modules using hydraulic cylinders then you could create a combined suspension/parallelogram module by placing springs in the cylinders. The suspension would be dampened by how much the fluid flow was regulated. If sufficiently strong springs were placed in the cylinders and the springs were distance limited the wheel would(forgoing a sufficiently heavy rider) on flat ground ride with the hub within a few mm of dead center.
(I’ll make a drawing tomorrow)
Springs don’t create energy, they store it, and without springs there would be no restoring force to make the suspension return along its travel. What you need is a spring damper with a sufficiently large damping coefficient (c) and a small spring stiffness (k) so that the response is heavily overdamped, which would supress bucking after landing a drop. However, this would effectively ‘stiffen’ the suspension so that it would be defelcted less when landing a drop, and the shock absorbancy would be decreased. What you need is two way shocks with seperately adjustable bump (compression) and rebound (exstension) characteristics. This would allow you to run the bump with a lower c than the rebound, so deflection on landing would be large and rapid, but rebound would be slower and more controlled, to avoid bucking. Such things exist in the world of motorsport, but while they outwardly appear almost identical (except for two adjusting knobs instead of one) in terms of internal complexity and price they are some way above single-adjustment shocks.
Your promoting his produt he should be happy for your addvitising:D !
Well i think it a cool idea that u want the shocks in the rim but u want the wheel stiff otherwise ur going to get sea sick from all the up and down motion u will get from it. if ur trying to comfer ur ass more lol get a seat post sock or just suck it up i know from riding a full suspension mountian bike once i hit the trails i felt the bike taking every bump witch was nice but on a uni it could only get worse b4 it gets better… well thats my 2 cents
damnn i’m broke now
use the canondale’s head shock idea i think it would work best
That’s an awesome idea 
! but in real life it wouldn’t work.
when you push 1 of the shocks, the other 2 won’t move.
if the shocks could move at the hub itself it would be possible.
Discus this uni whit a “know-all” and you’ll get something great out of it;)
:o sorry for my bad English:o
How would this work? You would need a light, “flexibal” rim with the ability to return to perfect O. you would also need to have the suspenion to you weight so it wouldnt compress when riding, but from under the pressure from a drop.
Nice designs though. i can only use pro desktop:D