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esaj

Wheel suspension?

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Seeing vee73's motocross-track video, and how hard the wheel jumps up and down all the time, it got me thinking if it would actually be possible to build some sort of suspension into the wheel. After doodling a bit, I went into TinkerCAD (A free simple 3d-modelling tool that runs on your browser) and created a crude basic shape of what I was thinking (not really in scale). It's a kind of a "two-sided swing fork" (if that's even the correct term in english). Now, I don't know if this would ever actually work in real life (it could become too heavy, move the center of gravity too much upwards, simply break under stress etc.), I'm not a mechanical engineer. Or not much of a drawer, or modeler, for that matter, so I'm not even sure if you understand what the image is supposed to be  :D

 

suspension.jpg

 

As the motor is inside the hub, the wiring would also need to be able to withstand constant moving, the uppermost axle should never hit the tire (I put it too low in the 3d-image, it's not supposed to be touching the tire)... Lots of mechanical problems ;)

 

Edit: thinking it further, maybe the "swing arms" aren't even needed..?

 

suspension2.jpg

 

 You guys got any ideas?

Edited by esaj
Added image

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I think your second idea is better, more like motorcycle front forks, keep it simple and light weight, weight is always going to be the problem.

I have discussed the idea with vee73  recently of just putting some compressible hard rubber into the pedal hinges to give a very rudimentary suspension.

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One more idea, even simpler... ;)

 

suspension3.jpg

 

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Going for a monoshock fork is one of the suggestions I've made in the past but you would still need some form of guide rails to prevent twisting and swivelling.

Weight is also still going to be a factor.

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Going for a monoshock fork is one of the suggestions I've made in the past but you would still need some form of guide rails to prevent twisting and swivelling.

Weight is also still going to be a factor.

Yeah, the weight would definitely be a problem, and the placement of battery and mainboard + wiring. Individually suspended pedals would probably also be problematic, as it would make steering and general riding very hard, so they need to move in unison. Monoshock might work, if the shock absorber is very short (there are mountain bike shock absorbers that are 140mm = 14cm eye-to-eye or even below, 123mm?), the attachment on both ends would need to be probably through-bolted (and welded?) in relation to the horizontal rods/bars, that might be enough to prevent twisting..?

 

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I believe that the suspension pedals to drive the same thing and it is easier and lighter to implement.

Certainly in the future when people will start to run Extreme, comes even what kind of spring-loaded versions.

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You cannot just add springs between the wheel and the case without needing a shock absorber as well.

Don't forget, the reason why suspension works in cars is that the car itself is much much heavier than the wheel.
In an EU, the ratio between the wheel and the rest + rider is much smaller.

Instead, I would like to have some spring loaded pedals that have the ability to travel up and down a small distance.
I don't think it would need to be that much, about 2 cm at most. It would only be needed to catch those movements that will make your feet loose contact with the pedals for a short moment.

I am not sure about you guys, but every time I make a jump off of something, my feet tend to loose contact for a fraction of a second.

When going over things, I simply bent my kees a bit more and my legs act as the shock absorbers.

 

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Try to change the angle of the pedals.
I've got it helped.
I squeeze the device tightly between my legs where there is a lot of bouncing of the road.
But a little flexibility pedal helps a lot.

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There was a picture of a euc with individual suspension to each pedal built into the frame leg.

It was there that I suggested the pedals needed to be linked with an extra internal fork a bit like a mono-shock set up.

My son says he would like to have better contact/attachment to the wheel. I suggested cycling shoes with the pedal type attachment that you could clip your foot into, but personally I think that could be a little suicidal, even if you only clip one foot in.

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There was a picture of a euc with individual suspension to each pedal built into the frame leg.

It was there that I suggested the pedals needed to be linked with an extra internal fork a bit like a mono-shock set up.

Yeah, I'd go with some form of linking between the pedals, I think individual suspension would probably make the wheel harder to control and wobbly, as the suspension would affect also when shifting weight to other pedal for leans and such. Stiffer, short shock absorber (not just a spring, as spring would keep oscillating after movement) MIGHT do it if linked above the wheel fork, but as you suggested before, it might also need some separate guide rails to prevent twisting or swiveling around.

 

My son says he would like to have better contact/attachment to the wheel. I suggested cycling shoes with the pedal type attachment that you could clip your foot into, but personally I think that could be a little suicidal, even if you only clip one foot in.

I use locking pedals when going bicycling for longer routes (20-75km), and I wouldn't ever use such on a wheel. Even when you're used to them, unlocking them in a hurry is not easy. I've set the locks pretty tight, so they won't come off ever pulling upwards, so I can pedal with forward-down-backward-up -movement, using my leg muscles all the way the entire circle. To release the lock, you need to bend your ankle outwards (or inwards) about 10-20 degrees. With less tight locking, you can get your foot free by pulling upwards, but on an unicycle that might not be good either (if you trust the lock to hold your feet on the pedal, but suddenly when dropping over a curb or such, the lock opens, or might open on a hard jump).

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I did tell him I didn't think it was a "sane" idea and that if he must have better connection old fashioned toe clips would probably be better if left untightened and fairly loose.

In fact I seem to remember seeing some mountain bike toe clips that were made of stiff plastic and strapless. They might possibly work.

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I did tell him I didn't think it was a "sane" idea and that if he must have better connection old fashioned toe clips would probably be better if left untightened and fairly loose.

In fact I seem to remember seeing some mountain bike toe clips that were made of stiff plastic and strapless. They might possibly work.

​How about using straps instead of clips? Something like slipping your feet into slippers or sandals? In an event of an accident your feet have a better chance of sliding out. If clipped in then you risk the chance of serious injury. A 20-30Ib wheel twisting out of control with a foot attached makes me cringe. 

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I think I mentioned suspension in one of my posts ( I'm a genius!). I agree with pedal suspensions. Could be real simple. 

Edited by Planetpapi

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Ah, suspension on the pedals instead of the wheel. Excellent idea! Does it have dampeners too?

That Rockwheel looks awesome! Give us more info please :)

Edited by Lorents

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Well done arbee, you found the picture.

That was the one I suggested might be better if the two sides were connected so that they both rise and fall together.

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Off-road driving pedal is being lifted up that the suspension is lowered pedals hit the rocks and others.
I would estimate that at least 3cm.

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New Rockwheel. Tell me more ..

​This photo was posted by Rockwheel founder on Facebook December last year.  Maybe just a prototype.  Never heard about it again after that unfortunately.

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hmm love to se a fully adjustable mono shock with adjustable high an low speed damping like track shocks on motorbikes only problem is wont be cheap

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The suspension must work in parallel on both sides. One side only will result in stability issues while riding the EU. I personaly like to ride a hardtail. Direct, sporty and controlled.
It would be interesting to see how much difference would be with suspension/ hardtail on power consumption peaks to prevent torque balancing issues.

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What about these tires from Schwalbe? These tires are supposed to have that suspension feel. I never used them nor know anyone who has them. Anyone here try them? Seems like a good compromise between comfort, sportiness, and durability. 

http://www.schwalbetires.com/bike_tires/road_tires/big_appleapple

Air suspension built-in. The Big Apple started off the Balloonbike trend ten years ago: Comfortable cycling without using complicated technology! Air cushion tires are used as natural suspension. Inflated to 2 bar a balloonbike rolls really easily and with a full suspension effect.
Enjoy unique Balloonbike comfort. Because life is hard enough.

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The suspension must work in parallel on both sides. One side only will result in stability issues while riding the EU. I personaly like to ride a hardtail. Direct, sporty and controlled.
It would be interesting to see how much difference would be with suspension/ hardtail on power consumption peaks to prevent torque balancing issues.

​This. The nature of how we ride these self-balancing vehicles just makes any type of force dampening system non-feasible. Its the same issue of trying to ride an EUC on cushy carpet. We need a relatively hard surface/system that gives us almost instantaneous feedback so we can easily stay balanced on our self-balancing wheels. That doesn't mean one could add a damping system and just learn to get used to the more difficult ride, but in the end I don't think its worth the trade off. Probably why Rockwheel hasn't pursued anything else since that picture from last year. 

With all that said, I'll be glad if someone comes up with something. I saw this "Shockwheel" a while back and was thinking about it on an EUC. Think it might suffer the same negative balancing effects as a regular shock system.

 

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