Suspension MUni

As long as the suspension is directly linked to transmitting power from the pedals to the wheel you will have problems. Stiffening it up so it doesn’t affect pedaling is not the answer I think.

I don’t know if its possible. It would be awesome to have suspension for your feet though. :slight_smile:

I think it’d be interesting to do big drops on a MUni with “suspokesion”, it’d kinda turn into a kangaroo wheel upon impact. Assuming you were aiming for a “correct” rolling landing it’d make it a bit harder to pedal at first (which isn’t necessarily a bad thing) and then moments later when the hub was on its way back up to the center of the wheel it’d (I think) become easier to pedal. It’d take a bit of getting used to but it’d be cool!

I’m thinking a 3 pronged suspension unit (like in the 3d models at the start of this thread) with only 2 of the 3 having hinges between the hub and the rockshox (so 5 hinges in total) would work in terms of a “beautiful suspension action”. I was thinkin some sort of ball in socket joint for a hub would be interesting (if only slightly impossible)…

If anyone’s got any more brilliant ideas or things to add about suspension MUnis, please post them up and I’ll have a go at incorporating them into another 3dmodel, that way we all get to stare in wonder at them without havin to go through the hassle of actually making them. :stuck_out_tongue:

By the way, a few people have been asking about this, the answer is I’ve been using Lightwave3D 7.5c (www.newtek.com) for the models, it really is the complete package in terms of “out of the box” bang for your buck. I highly recommend it to anyone wanting to get into 3d modelling or 3d animation.

cheers
Pete

Here’s a page from the November 2001 issue of “WWI Aero”, showing an old advertisement for an aeroplane wheel with “suspension spokes”. I copied the picture to a fairly large size so as to not lose too much detail. Any ideas here someone could borrow for a suspension Muni??

Doug

Jeez - including the picture would have been useful…sorry!!

D.

Being under an aeroplane, these wheels won’t have to transmit driving forces, and probably no braking forces through the hub either. That makes it easier to have spokesuspension. If you would drive (or brake) the hub, the suspenspokes would probably wind up significantly before much torque were transmitted to the rim.

Klaas Bil

Klaas,

That’s an excellent point about the wheels winding up under a driving/braking torque. It would be interesting to try building such a wheel to see how you could minimize the “wind-up” problem, without sacrificing all of the suspension travel - seems like there could be an acceptable compromise somewhere. A certain degree of “wind-up” under torque, together with the springiness of the suspension would certainly add to the challenge of riding, wouldn’t it!

Doug

Originally posted by dforbes

Yeah, that’s exactly what I was talking about (quote: ‘‘it had curved metal plates disposed as spokes.’’)

It was really similar, but the wheel I had seen was on a very old picture of a Penny-Farthing. So in theory it wouldn’t be a problem to propulse or brake the wheel. I still wonder why they didn’t keep on with the idea… :roll_eyes:

Imagine riding with two loose cranks, too-loose spokes, and your brakes rubbing all the time. That would probably be about as annoying as riding a wheel that wasn’t absolutely stiff in the driving direction. You would waste energy every time you made a change in speed.

Plus that airplane wheel, as pretty as it is, doe not look very light. Obviously if it was a good alternative, it would have found its way onto at least one airplane?

Yeah, any brilliant idea that didn’t catch on, didn’t catch on for a reason. The thing is if you can find that reason and fix it THEN you have something useful. :slight_smile:

Thats AWESOME! it would be so cool if it worked good.

would it not be hard to hop?!

Amazing models! Thanks for sharing.

Andrew

So, I just now noticed that the pedals are on the wrong sides, unless someone took the time to swap the spindles… meh. Im a bit nit picky about that, im going to a corner now.

Why? Could be easier. Why do you think trials riders lower their tire pressure? To get more spring. With suspension in the rim you could keep your tire pressure higher because you’ll get spring from the suspension.

Re: Suspension MUni

On Tue, 18 May 2004 19:38:00 -0500, “aust” wrote:

>would it not be hard to hop?!

Maybe, because of the weight. But the springiness of the wheel would
be beneficial to hopping.

Klaas Bil - Newsgroup Addict

be sure to remove the saddle and simply sit on the seat post. this is far more comfortable - tennisgh22 on the comfort of Savage unis

The Ackerman wheels were actually used in the J.V. Martin K-III “Kitten”, which was powered by a 2-cylinder, 45 hp motor and had an empty weight of only 159 kg (350 lbs). Although those wheels can’t have been as light as conventionally-spoked wheels, perhaps they were lighter than a combination of spoked wheels + shock-absorbers would have been? The wheels were incidentally part of one of the first semi-retractable landing gears ever used (1918).
With today’s materials it might be possible to make an Ackermann-style wheel that wouldn’t be too heavy - but you’d still have the wind-up problem Klaas pointed out in an earlier post.
A “springy” wheel would probably make a lousy suspension Muni - but it would be fun to try to ride, and a rider in motion would certainly look odd, bobbing up and down…maybe the prototype had better be tested somewhere out in the desert away from the prying eyes of press and public.
:slight_smile: Doug

Something for our new comrade Kraze in Iraq?

So, no, not in Iraq.

Klaas Bil

Actually I think it would be real easy and fun to hop. You could bounce all over the place. This would be its strongest point. Riding it would be the sukky part, due to the wind-up.

I can’t think of a way off the top of my head to eliminate the wind-up and still have a way for the wheel to be springy. I’m sure there is an engineering solution out there somewhere though…

That the springy wheel was used on a 350 lb airplane attests to its lightness. In those days of course, most airplanes did not have suspension systems so that was probably a nice feature.

I may have an idea that would work. I’m going to try and model it up in Rhino3D.

This is the idea someone else and I came up with. Basically the same idea as the first, with 6 hingest, 3 on the hub, 3 on the rim. But add a 4th shock which would be one piece with the hub and hinged at the rim. It would not contribute any spring to the compression. It would have no spring, no dampening. This is to prevent uneven compression. I believe this would allow for suspension inside the wheel, but would also keep the hub rotationally rigid to the rim. Let me know what you guys think.


You might have to copy and paste the address.

Another render with the telescoping piece of metal modeled a little differently. You all realize it would be free to slide. It would just be a strong telescoping piece. ALL of the rotational torque would be sent through this piece and NOT through the actual shocks.