UniChris

On the contrary, my conclusions come specifically from having ridden them. They're cool, but have little actual utility outside some interesting niches like a camera platform.

Not really, they're quite heavy to lug around when done riding, and especially on and off trains or worse busses, up stairs, etc. They especially have the problem of having a large mass of hub motor and battery enclosed in a bulky housing dictated by the tire, so they don't carry as well as the same weight in friendlier shape that hangs closer to the body would. And making the wheel smaller, which I also tried, leads to a poor ride quality.

Electric last mile transport is a decent idea, but a minimal little folding-handle scooter is probably the most practical form - once you stop pedaling a bike form factor is indeed unnecessarily large.

In the long run, last mile is also a social and urban planning problem as much as an individual one. Making cities bike friendly is already challenging enough given that only a fraction of the population could see themselves biking. If there's going to be an electric last mile option that most people on the street could see themselves trying, and thus one that could potentially come to be fully integrated into city design, I expect it's going to be the scooters, more than pedal assist bikes.

I didn't say they couldn't be fast, I said you do not want to ride one faster than you can run. Because, as you point out, it doesn't take much to make you fall - and if you do, you want to be moving at a speed at which you can instantly start sprinting, so that you don't actually go down on the pavement.

LanghamP

To be specific, you have ridden a 14, 16, or 18 inch wheel with an integrated trolley handle? Where the handle pops out of the body?

And I'm specifically referring to the seatless unicycles, that only have the folding footpads.

For example, the Inmotion V8 is a 30 pound wheel that folds up into something not much larger than 16 inches and only a four inches thick at its widest point. This is a foldable wheel that can be trolleyed under its own power. It's tiny when folded up!

It's like we're talking about different objects, our experiences are so wildly diverging as to be from different planets.

I use mine several times per week on public transport, and this wheel sits next to me on my lap, or between my legs, or placed upright against the wall of the tram. It's unnoticeable, much smaller than just the front wheel of a bicycle although much thicker.

.

To reiterate, you've ridden these types of wheels? These specific kinds of recent generation wheels?

Iride01 

Why wouldn't you ask them?

rollagain

Sorry I got a little overheated, but I do understand the difference; if you'll look back at my posts in this thread you'll see a mention of 'cross-sectional stiffness' and 'girder.' I thought to mention the lack of elasticity in the low-carbon steel the OP referred to, but didn't know if that would cause confusion.

I still wouldn't use the stuff for anything but maybe a decorative fence. Common square- or rectangular-section box channel would be far better; that stuff is used for a lot of trailer framing. Getting it rolled into a hoop still requires an industrial machine, though. Round-section tubing would be lighter for equivalent strength--excuse me, stiffness.

Aluminum box-channel has been used for some experimental HPVs: Manual for xyz spaceframe vehicles
I'm not sure I'd count on those for longevity.

I still like the idea of plywood best for this project.

Milton Keynes

I really think you either need to find a metal roller or find someone who has one and can bend the tubing for you into a perfect circle. If you try to do it yourself without the proper tools I'm betting you'll end up disappointed since the wheel will be less than perfectly round.

fietsbob

Practicality?, nil, attention getting much more.

nishiki12

Do bike shops have roller benders?

UniChris

We are talking about the same things. I believe we mostly had 14 inch models, (or maybe they were 16). I also tried an 8 inch that I thought might be more practical, but it handled poorly. And right before I left we got in a larger one, though the sheer heft of just wheeling it around the lab (it had a defective motor driver) pointed towards it being the wrong idea.

Now, having just returned from a 20 mile pedal-unicycle ride with a road rash knee (the plan was 49 miles), don't let me discourage you from doing what interests you. But there's a difference between doing something because you want to, and doing it because it's practical.

Dimensions seem a hair small - 4 inches would be a very short axle, and is there no fender on that model?, but even so, 30 pounds is not trivial when you get to stairs.

They're banned on our transit, over the same battery concerns as the "hover boards" (which are after all just two connected electric unicycles). E-bikes seem to be tolerated, but that's probably only because they haven't been thought about specifically.

But it's not just that they're too risky to ride fast, it's that they are too unusual. Last mile transit only really works when society as a whole gets behind it and creates policies and infrastructure to support it. Right now, barely anything electric is allowed in the bike lanes, and absolutely not on the sidewalks.

I could really see accommodation happening for electric scooters - almost anyone who can walk unassisted can ride one. But it's not going to happen for electric wheels with their tiny market appeal. Maybe the way scooters will be accommodated and their batteries certified to be allowed on transit again will be something you can piggyback off, or maybe it won't.

The electric wheels are never going to be more than an oddity, in fact you see fewer of them now than a couple of years ago.

But if you enjoy yours, then enjoy it.

LanghamP

You aren't competent to offer advice on electric unicycles because you haven't ridden one, or ridden one so little that you haven't an inkling as to its size and brand, or haven't attempted to ride one in practice (ie on the street), or you wheeled around a broken wheel and judged all wheels with that single sample point.

It's absurd, unscientific, ghastly, and ridiculous.

It would be like me going to kick tires at a used car lot, seeing a Trabant fired up, and then offering advice as to why these autos aren't practical.

Take a modern 14, 16, or 18 inch wheel out for a spin, including on public transportation (only downtown Berlin and downtown London specifically forbid EUCs, and only for riding not transporting), and then come back to post here when your experience with wheels is more than zero.

​​​​​​

fietsbob

No,

You need a fabricating machine shop , maybe one of those guys
that make those full custom chopper motorcycles,
.. as seen on TV.

UniChris

You have no idea what you are talking about. We sold them. I rode them, taught people to ride them, evaluated competing models, intentionally overleaned them into overcurrent shutdown to find the limits of the system, disassembled them and rebuilt them in other forms, fixed them...

You just can't accept that fact that someone who took a cold, hard, look at the idea came to the supported conclusion that your toy has too many issues to be practical transport for most people.

And that's even after you yourself agreed with some of the key facts behind this - ie, they are dangerous at speed, and they weigh in the neighborhood of 30 pounds.

In narrow circumstances of good safe paths, a permissive legal and social environment, no stairs to carry it up, and a moderately daring rider - sure, it can work. But a scooter would be safer and easier, and a bike or walking would give you exercise. So mostly you're left with the sci-fi cool factor.

Enjoy riding yours.

LanghamP

What organization did you work for, and what brands did you evaluate, and who did you train using what methods?

I'm highly skeptical of what you say, it all doesn't add.

Hell, I'll call you. That'll settle this quickly.

UniChris

Go ahead can call me a liar if that's the only way you can reconcile the fact that other experienced people disagree with you and settle your thoughts enough to enjoy riding your purchase.

Meanwhile reasonable people can weigh the arguments - all of which are amply supported by many other people in many other places - for themselves.

nishiki12

Christ, can we get back to the point at hand? Monowheels?

rollagain

Not sure how bad this topic is drifting, but I thought of another tangent today. It may be the first original idea I've ever had, but more likely not--not original, that is. Split this off into another thread if you want.

Here goes. Start with a penny-farthing. Replace the front wheel with a man-driven monowheel such as the OP wants to build. Construct a steering fork to join the monowheel to the penny frame. Equip the penny rider's position with an additional pedal drive for the monowheel (that's the really tricky part).

Three-way hybrid penny-tandem-monowheel. Stoker below, captain up top.
Keep in mind that the steering fork needn't look like a bicycle steering fork; it can attach to the mono frame rather unobtrusively. Mono can be detached and ridden solo, or the combination can be ridden solo as a penny.

I'd love it if somebody here would sketch this up; I don't have the resources.

UniChris

Sounds very fun as a parade float odd bike.

If you were going to actually do it, I think it would be important to get the weight of the external rider very much further behind the wheel than on an actual penny.

The main penny risk is going over the bars, since the distance of the saddle behind the contact point is so short that you're just short of riding a unicycle to begin with, only if you do overbalance the handle bars block running out the fall on your feet in the way you most of the time can from an actual unicycle.

The reason a penny rider has to sit there is to reach cranks attached to the axle, but with a rider inside the wheel you won't have an axle to begin with - instead you'll have some sort of roller drive mechanism at the rim not unlike the inside rider uses, so you might as well sit safely behind the contact point.

Or add a third rider over the "farthing" as an additional counter-balance (just make sure they don't get off without telling you!)

You'd also have to consider mounting dynamics - I'm not sure the internal rider's splayed legs could safely stabilize things for the penny rider at stop (though it might be a dangerous temptation to try), so the external rider may still need to do the traditional scooter-coast start/stop from the mounting peg on their way up to and down from the saddle.

Thinking about it more, there is an issue of the external rider's pedaling mechanism slewing side-to-side in turns if it's not near the steering pivot, and moving the steering pivot substantially behind the contact point raises questions of trail that seem like they would need careful analysis. Alternate possibilities might be something like having the external rider pedal a chain driving the farthing, or even making the frame fixed and going with a steerable tail-wheel. This part would definitely take thought, and very careful testing before riding it above a moderate walk.

I keep thinking it would be fun to have a convertible unicycle/mini-penny frame for a 36 inch wheel. Seems like it could be just a matter of coming up with something that could function as both a seat tube and a head tube, and then having the trailing frame fit over that.

rollagain

What if the external rider's seat and pedal drive were fixed to the steering tube. He could be maybe semi-recumbent with his CoG back a little. Crank ahead of the steering tube, under-seat steering attached to the main frame. They'd need a couple assistants to hold the whole thing still for the external rider to get on and off, and who knows what the steering dynamics would be (likely a nightmare) but his drive would be simpler.

Probably not such a great idea, but it's fun to throw what-ifs around.

UniChris

I thought about that, but would actually have to see a body superimposed on a wheel to figure out if it would work - my gut feelings was it would be awkward, but could be wrong. Also, the extremely experienced unicyclist who built recumbent unicycle reports that the reclining position really complicates balance - technically in a penny you aren't trying to do that, but I suspect it would still be quite unnerving.

Another possibility might be some sort of spherical-bearing splined thing, to allow a sprocket on the steering axis at the top of the wheel to be driven by a chain from behind it. Not having ever actually had the privilege of climbing onto a penny farthing, I don't know what sort of range of angular rotation you actually need for steering, but obviously it can't be too extreme.

Where I to suddenly find myself in possession of a backyard fabrication shop, I'd probably go for the Seuss-esque parade triple: rider inside, rider atop, and someone bringing up the rear on the farthing. Possibly with three the captain could just steer and not contribute - so basically a monowheel with a small fork to pass the rim on top, joined by a long swooping penny frame to to a kiddie tandem with a layback seat to fit an adult, and passive seat with steering bars up top for the captain.

And each needs a big honking horn, if not an actual brass instrument.

UniChris

To emphasize the collective response to the original, now pointlessly duplicated question, no there is not really any alternative to hoop rolling.

There there wouldn't have been one historically, either. The way you manufacture a uniform steel strip is by rolling to begin with; rolling into a hoop rather than flat is just a carefully calibrated defect - if anything, it's rolling a flat strip that took time to perfect.

For a bike:


For a monowheel (rim rolling is the first few seconds after intro):

rollagain

UniChris, you gave me a double-take with "recumbent unicycle"--I had to look that up. I wouldn't say they were recumbent, really, just crank-forward ... still. Thanks for sending me on a little exploration journey; I found John Foss's page and some youtube vids. Fun stuff, and things I don't believe I'd ever have thought of. The only pondering I'd ever done about unis was why no one had ever put handlebars on them--yep, they have. That always seemed like an intuitive improvement, but then, you can't juggle.

I tried a uni once, a long time ago; my former brother-in-law had one and I tried it. I think I managed to stay on it for a few seconds and then I quit.

Yeah, that second drive arrangement is pretty problematic and I suspect a working solution might be really energy-inefficient, like for instance, cable drive.

UniChris

I assume you saw Corbin's? It has a bench seat rather than a saddle, though now that I look again there's no back on the seat. `bent riders usually push against the seat back, right? With probably a fairly low gear ratio it's not like you really mash the pedals on this, and not having the back may have been a consideration for mounting it if he ever tried it other than riding a way from support. I get the sense that it and the tandem uni aren't really ridden but brought out for laughs at post-ride parties, but I've never met him.

Introducing, the world's first human-electric bicycle... you pedal the dynamo, and the motor makes you go! It works for trains and ships and cars, why not bikes (j/k).

rollagain

@nishiki12 Not sure how dead this topic is, but if you're still interested, I found this elegantly simple but not very durable variation: