Larger wheels?

[InfiniteWheelie]

Edit; scroll down to see my later post about knee height, where I’ve reached a general conclusion about the topic.

Do you think we'll see larger wheels in the future, something like a 26-28 inch wheel?

Having a larger wheel has two big benefits in my mind. It basically acts like having suspension and adds safety. Also seated riding would improve greatly since the seat is just below your butt already. You wouldn't have to bend your legs much and you'd be sitting higher up.

The only downside would be weight and maneuverability at lower speeds. But I see a wheel like this being marketed as a high end street wheel. Something with a big battery, high speed and stability. Something like a real motorcycle replacement. Do you think we'll see something like this in the future?

Edited December 10, 2023 by InfiniteWheelie

[Tawpie]

I do. In addition to the benefits you mention it would give you more room to lower the center of gravity by mounting the batteries and pedal hangers lower... additional stability.

Edited September 22, 2021 by Tawpie

[Will R]

Yes definitely! Especially as manufacturers increase battery voltage and motor wattage. An experimental 26" kingsong was already created years ago by an Australian guy with much more basic technology than what's available these days. I'm sure if you paired an Abrams guts with a bespoke 26" rim like this you could eek out 70mph just from the diameter increase (not that I'd be in a rush to try it).

 

 

[Menace]

I'm going to go against the crowd and say no. Not in the form factor we know. The problem, like hsiang said in one of his videos, is that you have to muscle the wheel around to control it. You are pushing against your own center of gravity. At a certain point your weight becomes too small relative to that of the wheel and you can not move it around anymore. Imagine a 100kg rider trying to lean a 500kg electric unicycle (yes its huge, for illustration purposes) or get it to accelerate. As a 120lb rider, I already need power pads to get the full potential out of the 60 lb Rs. The giant tire will sacrifice almost all of the good things in the EUC (acceleration, hill climbing, responsiveness, agility, portability) for stability, which can be had with suspension instead. The Monster Pro is already slow to accelerate and pushing the boundaries as far as how big an EUC can be (from what I hear).

[Kekafuch]

1 hour ago, Menace said:

I'm going to go against the crowd and say no. Not in the form factor we know. The problem, like hsiang said in one of his videos, is that you have to muscle the wheel around to control it. You are pushing against your own center of gravity. At a certain point your weight becomes too small relative to that of the wheel and you can not move it around anymore. Imagine a 100kg rider trying to lean a 500kg electric unicycle (yes its huge, for illustration purposes) or get it to accelerate. As a 120lb rider, I already need power pads to get the full potential out of the 60 lb Rs. The giant tire will sacrifice almost all of the good things in the EUC (acceleration, hill climbing, responsiveness, agility, portability) for stability, which can be had with suspension instead. The Monster Pro is already slow to accelerate and pushing the boundaries as far as how big an EUC can be (from what I hear).

With that mindset , we would still be riding hover boards 

[Tawpie]

@Menace does have a point, but I think it'll require a slightly different riding style to maneuver. I see videos of kids riding wheels that they outweigh by 5 lbs—granted it's not at "speed" so it may not count. I am also a bantam flyweight (soaking wet, in full gear) and find that I turn my MTen in an entirely different way than my 16X... not sure why or exactly how it's different, but it is. True, at 20 mph the 16X doesn't want to turn with a thought, and it requires a bit of coaxing with the knees but with the proper tire profile I'm pretty sure I can lean a larger wheel into a turn, at speed. It'll take practice, but I do believe it's learnable. Countersteering will probably be involved. The challenge for the manufacturer of such a large wheel will be market opportunity—because it'll be a pavement eater they'll be giving up a segment of the market that isn't looking for 45 mph for hours on end and it's difficult to survive if you're too far from the cash money center of the market.

There's a Canadian project on Kickstarter (Orion) that promises a massive tire—cost to backers is something like 4100 USD and that'll be 1200 USD below the eventual MSRP. I think they have 1 person signed up for a wheel and another person who's a supporter. Pickins are pretty slim at that price point, but at least 1 person is willing!

Edited September 22, 2021 by Tawpie

[InfiniteWheelie]

19 hours ago, Menace said:

... The giant tire will sacrifice almost all of the good things in the EUC (acceleration, hill climbing, responsiveness, agility, portability) for stability, which can be had with suspension instead...

Acceleration and hill climbing are only affected if you are using the same motor. You can wind a motor any way you want to trade off speed and acceleration. But the other things are cons for sure.

@Tawpie That Canadian wheel, that's what i'm talking about! Check out the first video on the kickstarter page, that thing is huge! I wonder how many inches it is.

Edited September 22, 2021 by InfiniteWheelie

[mhpr262]

I can see such wheels specifically built for seated riding - with a geared drive system that consists of a big, fast spinning outrunner motor mounted in front and a low geared belt drive that connects it to the wheel

[mike_bike_kite]

On 9/22/2021 at 2:07 AM, InfiniteWheelie said:

Having a larger wheel has two big benefits in my mind. It basically acts like having suspension and adds safety. Also seated riding would improve greatly since the seat is just below your butt already. You wouldn't have to bend your legs much and you'd be sitting higher up.

But suspension also acts as suspension and it seems to work fairly well on current wheels. You'd need a more powerful engine and that would mean a heavier engine, there's also the flywheel effect which would make turning difficult. The safety aspect of a big wheel is offset by the problem of not being able to brake or turn quickly. You'll just end up paying more for a wheel that's less manoeuvrable than current wheel and is harder to accelerate and brake. You could add a seat post to seats to make them taller or some other rising mechanism and that might get round the seat height problem but then how many people actually want to ride sitting? I suspect most folk do it because they want to show that they've learnt how to rather than because they actually want to ride seated. There used to be the KS18S (not the S18) and that had a high seat but it wasn't a top seller. You'd also loose out on the ease of taking wheels into shops and buildings without security throwing you out. I don't see larger wheels as a step forwards.

[Nostris]

I can’t see it really. The bigger wheel = more comfort argument is fine up until a certain point, then it starts to loose comfort and, more importantly, convenience because of its physical size. They went through this thought process when the bicycle first came out. The Penny Farthing with its massive wheel was to give more comfort on the unsurfaced roads and cobbled streets of the day, eventually it was found to be unpractical and inconvenient because of its size, so the smaller more compact bike became the norm. 

[InfiniteWheelie]

Another example of a large wheel...

 

[Guest]

There are already large wheels with a place to sit. It is useless to build larger diameter, it changes the product which would become another product coming out of the wheel. For the state of mind mentioned above this is unrelated to hoverboards, it is another vehicle that has a different audience. Two different vehicles require specific skills and performance, and give two sensations that can be expressed side by side.

[InfiniteWheelie]

After looking into tires more, we can basically determine a maximum size based on available tires. A big, heavy, fast wheel requires motorcycle tires. In my opinion the best default tire type is something like what the Sherman comes with. A good all around tire that does well on dry roads, wet roads, some off road etc. In the motorcycle world these are called dual sport tires, which are somewhere between the highly slick street tires, and the gaping knobs found on dirt bike tires. Dual sport tires come in many tread patterns, some more road oriented and some more off-road oriented, but they all land somewhere in between.

Knowing we need dual sport motorcycle tires, what's the biggest available size? The biggest common rim size (meaning good tire availability) is 21" which would give a tire size of around 27". So this is basically the practical limit in terms of size. The next sizes down are 19" (25 tire"), and 18" (24" tire) which is the size used on the Monster Pro.

I would be interesting to see if the last two remaining rim sizes (19" and 21") are ever utilized in the future. I have no idea how they would work out in reality but it's possible they could make amazing high speed wheels. 

Edited September 5, 2023 by InfiniteWheelie

[InfiniteWheelie]

Some benefits I imagine from a larger 19" or 21" (rim) wheel, with more power to match...

- Higher range & longer battery lifespan

- Higher top speed

- Better acceleration/braking

- Less chance of cutouts

- More stability at speed and over bumps (possibly negating the need for suspension)

- Ability to go up and down curbs/stairs without effort (including while dismounted).

- Greatly improved seated riding

The only cons I can think of (other than maybe worse low speed handling) are things not actually related to riding. Thinks like cost, carrying weight, storage, more conspicuous etc. It seems like it's almost entirely positives in terms of riding. I'd love to try out a Monster Pro sometime as that's the biggest wheel out there currently. I considered buying one but the quality and torque just isn't there from what I've seen.

Edited September 5, 2023 by InfiniteWheelie

[InfiniteWheelie]

It’s been a while, and I wanted to update this thread with what I’ve learned. Tire availability isn’t actually the limiting factor for tire diameter, it’s really the height of your knees. The is mainly because above the knees, the legs rapidly narrow. Your feet get forced towards the edge of the pedals just to fit the wheel between your legs.

So what is the maximum tire diameter? It’s basically pedal height (fully compressed) + knee height. Without boring you with the numbers, it works out to roughly 22-24”. Now let me explain this further by talking about rim size.

We basically end up with a maximum rim size of 17-18”, depending on the overall design of the e-wheel. The Monster Pro gets away with an 18” rim because of its side mounted controller and contoured top. The Abrams uses a 17” rim, but it’s an ergonomic nightmare for anyone under 6 foot tall. This is because the Abrams has a very tall top-mounted controller box and no contouring. If it had a much shorter controller box and contouring, it would be fine.

Generally speaking, the largest and most optimal wheel size (which allows good ergonomics and design), is a 17” rim, equaling roughly 22.5” in tire diameter. This is coincidentally the standard rim size for street motorcycles, giving the best tire selection by far. Note that suspension has no affect on this (regardless of travel), though there are other reasons to consider smaller diameter rims/tires for off-road e-wheels.

Edited December 13, 2023 by InfiniteWheelie