Rider vs EUC weight

[mmk]

I realize there must be great variability here, I also think general guidelines could/might/ought to exist. Search wasn't very helpful.

So is there a golden rule rule, an ideal proportion between rider and euc weight/mass?

Full disclosure of my perspective, I am 180 cm and weigh just under 60 kg. 

[yoos]

No, there is no golden rule  Just recommendations all over the place. Anecdotally, there are some heavy riders 100+kg happily riding 16S (not S16!) etc. If you do indeed have a V11 (as your insignia suggest), you should be safe and comfortable. The less you weigh, the faster you can accelerate and the faster you can go uphill (or you can manage steeper hills - however you like to look at this). 60kg is on the lower end of the weight of the EUC ridership. It should give you an edge in hard-core racing if you decide to pursue this dangerous sport. Sometimes lighter people complain about managing heavy wheels, but there are also plenty lightweight riders riding relatively heavy wheels (e.g. check out EUCgirl on instagram). So unless you have to literally carry your EUC upstairs etc, handling the wheel with ease is mostly a question of experience.

[mmk]

Many thanks Yoos, I tried handling a V13 and concluded the 50 kg euc is simply too much for a 60 kg person, on flat ground, let alone on a ramp to get it into the car.

Forgot to mention I'm pushing 70, so hard core racing is well out of the question, along with hard core anything, pretty much, other than medical bills.

"

27 minutes ago, yoos said:

The less you weigh, the faster you can accelerate and the faster you can go uphill (or you can manage steeper hills -

Neither, nor, I'll settle for the extended range and even then.....

Thanks again

[on one]

2 hours ago, mmk said:

is there a golden rule rule, an ideal proportion between rider and euc weight/mass?

It depends on how you ride, for me, in general, being a heavy rider on the light wheel is optimal, because I don’t depend on the sides of the unicycle to control the unicycle as much as I used to, when I was relying more on leg contact with the unicycle to steer it, then a heavier wheel was better, but now the light unicycle is not twitching for me because I control it with my leg muscles instead of relying on the sides of the EUC , if that makes sense?

[mmk]

Makes sense, thank you.

So IF there were a golden rule it would likely be skewed towards a greater diff between rider and euc weight.

Wonder what a 100 kg rider would say were he to try handling a 90 kg euc, while being happy with a 50 kg one.

Playing loose, I see a pattern emerging.

 

 

[on one]

For me, I prefer the lightest, which is my KingSong 14 D and I weigh 245 pounds and the king song 14 D only weighs 32 pounds and that works great for me. It’s really fun I have a lot of control over that but when I was just starting out and learning, it was miserable to try to ride my KingSong 14 D because it was so twitchy because I was relying on the sides of that little wheel and it was miserable, but now that I learned how to balance without using the sides of the wheel for 14 D is perfect it’s just too low on battery

I was so miserable on the 14 D because my leg muscles were not strong enough to control the wheel without using the sides of the wheel. It was just hurtful and miserable the whole time but now that my leg muscles are a lot stronger than 14 D is a joy the ride.

[mmk]

Wow, your ride is all of 13% of your body weight.

I would need a 17 lb one to match that. Well smaller than Mten Mini @ 27 lb

[on one]

not really, You just need to develop your muscles taming the bucking bronco that is the Ninebot Z10. Then, when you scale down to something akin to King Song 14D you will be floating (in a good way) not floated as in The 100!

[slippyfeet]

I like wheels at/under 40% of my body weight (I weight 63kg, my heaviest wheels are ~25kg). 

[on one]

00 I got a factor this ratio into my formula .. . … rider weight to wheel weight

[kintips]

3 hours ago, slippyfeet said:

I like wheels at/under 40% of my body weight (I weight 63kg, my heaviest wheels are ~25kg). 

I'm with you i weight 59kg (with gear a little more), and wheels that are super heavy are not fun to ride. I mean i can do it but its work. That's why i like my falcon and the s16pro, 16x etc.. i was thinking of MTEN5 at one point because i love my MTEN4. But after the over heating issues, i will wait for a steep discount on it. 

because i'm sure begode will have to sell off the mten5 old stock since the plus is coming out

[rcgldr]

On 8/20/2024 at 3:36 PM, yoos said:

The less you weigh, the faster you can accelerate

The motor torque can only match the rider's torque (else the EUC frame would rotating backwards). If a rider is too light, even with power pads the rider can't generate enough torque to accelerate as fast as a somewhat heavier rider.

[Tomallo]

15 minutes ago, rcgldr said:

The motor torque can only match the rider's torque (else the EUC frame would rotating backwards). If a rider is too light, even with power pads the rider can't generate enough torque to accelerate as fast as a somewhat heavier rider.

But a lighter rider will need less energy and, therefore, less torque to accelerate to the same speed. If we're talking how much power a rider is able to make on a wheel overall, then a heavier person will probably win, that's true. But as for acceleration? I'd argue lighter riders have the edge. It'd be interesting to know and/or see math involved in all this, though. Unfortunately I'm not nearly good enough with physics and math to do that myself.

Edited August 21 by Tomallo

[mmk]

2 hours ago, rcgldr said:

If a rider is too light, even with power pads the rider can't generate enough torque to accelerate as fast as a somewhat heavier rider.

Torque has two components, actual force and lever distance,  so tall and skinny might make for a small advantage in terms of acceleration.  Also a minor advantage might be realized in terms of fewer losses like friction, heat, etc.

Ultimately the greater advantages for lightweights would mostly be visible in terms of range and likely in hill climbing, as stated before. But that's assuming the advantages are not negated by a bigger unit capable of greater output.

And of course, I could be completely wrong....

Edited August 22 by mmk

[kintips]

51 minutes ago, mmk said:

Torque has two components, actual force and lever distance,  so tall and skinny might make for a small advantage in terms of acceleration.  Also a minor advantage might be realized in terms of fewer losses like friction, heat, etc.

Ultimately the greater advantages for lightweights would mostly be visible in terms of range and likely in hill climbing, as stated before. But that's assuming the advantages are not negated by a bigger unit capable of greater output.

And of course, I could be completely wrong....

Youre right i get excellent range on all my wheels. I can get 45km easily on my mten4. Well anyone can ride heavier wheels the question is if you enjoy working at it. 

Also ive had wheels break down on me. I do not want to manually roll a v13 home with no power. I did that with a v12ht. 

[rcgldr]

4 hours ago, Tomallo said:

But a lighter rider will need less energy and, therefore, less torque to accelerate to the same speed.

From my post on the video thread about braking:

Wheel Good Time on an ET Max:

https://www.youtube.com/watch?v=SSJoKWCkxsE&t=273s

ET max weight = 108 lbs, tire diameter 20 inches.

Assume Wheel Good Time weighs 200 lbs with gear. 1 g braking means Wheel Good Time has to exert 257 ft lb of torque onto the ET Max.  Relative to the pedals, Wheel Good Time has to lean back 45° for the 1 g of braking and lean back further still for the 257 ft lb of reverse torque.

Assume EUC Girl weighs 100 lbs with gear, 1 g braking means EUC Girl has to exert 173 ft lb of reverse torque onto the ET Max. 

Torque to rider weight ratio: Wheel Good Time: 257 / 200 = 1.285, EUC Girl: 173/100 = 1.73. I don't know if she could accomplish that even with her Matrix lean:

https://www.youtube.com/shorts/ed5tLTjN-SA

A much heavier Wrong Way with his Matrix lean, probably a lot more torque and faster braking than EUC Girl.

https://www.youtube.com/shorts/r9qrpG38wks

 

Edited August 22 by rcgldr

[seshbones]

I weigh 115 lbs, and learning my Extreme makes me feel like a new rider... When I step on the V5F, there's no weight to it since it's 25 lbs. It feels snappy and responsive, which gives me a lot more confidence. I was able to hit tiltback the week I received it. The Extreme feels like it takes a second to respond (which is really just me having to lean further than I do on my V5F) and it doesn't twist-turn as easy, making it a lot harder to control below gyro-stable speeds.

On 8/20/2024 at 5:08 PM, on one said:

I was so miserable on the 14 D because my leg muscles were not strong enough to control the wheel without using the sides of the wheel. It was just hurtful and miserable the whole time but now that my leg muscles are a lot stronger than 14 D is a joy the ride.

I suppose the responsiveness of the lighter wheel required you to develop those muscles, I wonder where your sweet spot lies with ease of learning? Has there been a wheel that you stepped on and it just felt right? 

[rcgldr]

On 8/20/2024 at 5:08 PM, on one said:

I was so miserable on the 14 D because my leg muscles were not strong enough to control the wheel without using the sides of the wheel. It was just hurtful and miserable the whole time but now that my leg muscles are a lot stronger than 14 D is a joy the ride.

I don't understand this. Normally the issue is that there is a lot of pressure with the inner legs and upper pads when mounting on a short EUC, especially for a heavier rider. Once both feet are on, then little or no pressure is needed to ride. Some beginners tend to squeeze the upper pads too much at first. In anticipation of bruising, I bought cloth shin guards and turned them inwards to avoid | reduce the bruising. I used them for the first 10 sessions on my V8F, mostly for free mounting. Leg muscle strength wasn't an issue for me, but even with the shin guards, I was getting some bruising.

Some EUCs are so short that they can't be mounted in a normal way: the rider has to put one foot on lightly, then jump on with the other foot. 

1 hour ago, seshbones said:

I suppose the responsiveness of the lighter wheel required you to develop those muscles, I wonder where your sweet spot lies with ease of learning? Has there been a wheel that you stepped on and it just felt right? 

My guess is the issue was mounting or squeezing too hard on the upper pads.

Edited August 22 by rcgldr

[on one]

@rcgldr I learned how to ride on my KS14D. So, naturally I used the ankle pads a lot to manage the vehicle. But then after I learned the Z10 and got back on the 14D I found that I didn't need the pads at all, I just balance myself on the tire without really needing other contact points on the wheel itself, other than my big ass pedals.

[rcgldr]

On 8/22/2024 at 7:19 AM, on one said:

@rcgldr I learned how to ride on my KS14D. So, naturally I used the ankle pads a lot to manage the vehicle. But then after I learned the Z10 and got back on the 14D I found that I didn't need the pads at all, I just balance myself on the tire without really needing other contact points on the wheel itself, other than my big ass pedals.

I assumed you were probably squeezing upper pads a bit too much, but I don't get how stronger leg muscles helped in riding pedals only. My learning experience was a bit different. I started off at slow speed, 3 to 5 mph, twisting my V8F to steer (flail arms left to twist V8F right and vice versa), which did require some pressure on the upper pads, but found my V8F became stable at about 8 mph, and I could essentially stand still while riding in a straight line on smooth pavement, relaxed my arms and legs, using less leg muscles (not more). This is when I started to learn how to steer by tilting the EUC. At first both legs touching upper pads, later neither leg touching upper pads (pedals only), and then only outer leg touching outer pad (only useful if going fast enough to lean more than EUC is tilted). I ride pedals only (don't touch upper pads) when going straight.

Edited August 23 by rcgldr

[Tomallo]

11 hours ago, rcgldr said:

From my post on the video thread about braking:

Wheel Good Time on an ET Max:

https://www.youtube.com/watch?v=SSJoKWCkxsE&t=273s

ET max weight = 108 lbs, tire diameter 20 inches.

Assume Wheel Good Time weighs 200 lbs with gear. 1 g braking means Wheel Good Time has to exert 257 ft lb of torque onto the ET Max.  Relative to the pedals, Wheel Good Time has to lean back 45° for the 1 g of braking and lean back further still for the 257 ft lb of reverse torque.

Assume EUC Girl weighs 100 lbs with gear, 1 g braking means EUC Girl has to exert 173 ft lb of reverse torque onto the ET Max. 

Torque to rider weight ratio: Wheel Good Time: 257 / 200 = 1.285, EUC Girl: 173/100 = 1.73. I don't know if she could accomplish that even with her Matrix lean:

https://www.youtube.com/shorts/ed5tLTjN-SA

A much heavier Wrong Way with his Matrix lean, probably a lot more torque and faster braking than EUC Girl.

https://www.youtube.com/shorts/r9qrpG38wks

 

Interesting, seems right. I wonder what else is at play here; for example, how much of a difference would the ability to shift your weight quicker make? Like a heavy person with tons of explosive strength versus a small person that's very nimble, or if there's an optimal weight of euc for a given bodyweight.

Edited August 22 by Tomallo

[mmk]

1 minute ago, Tomallo said:

, or if there's an optimal weight of euc for a given bodyweight.

Exactly my initial (incorrect) assumption, but I still think a rating of "ideal" suitability should be possible, at least in terms of ranges since specific figures would be too rigid.

Exceptions and extremes will always be around, but they're still only that.

[xiiijojjo]

I still believe 2.75:1 body weight to wheel weight is the Ideal ratio to be strived for for the level of control and planted feeling it provides.

At least that's what I seem to enjoy most.

[yoos]

17 hours ago, rcgldr said:

The motor torque can only match the rider's torque (else the EUC frame would rotating backwards). If a rider is too light, even with power pads the rider can't generate enough torque to accelerate as fast as a somewhat heavier rider.

You are right, provided neither rider in your comparison reaches the wheels torque limit.

However, most experienced riders are potentially able to overlean their wheel (i.e. outtorque the wheel). And if both riders are able to reach the wheel's limit, then the lighter rider will benefit from higher acceleration on the same wheel (provided he is able to match the max torque of the wheel with his technique).

Maybe I am a bit behind current events, but I had the impression that a reasonabe-sized rider (e.g. 50+kg) can still overlean pretty much any wheel of the market? It's just that it requires you to be brave enough to lean selflessly and you would probably need powerpads.

[xiiijojjo]

4 minutes ago, yoos said:

However, most experienced riders are potentially able to overlean their wheel (i.e. outtorque the wheel). And if both riders are able to reach the wheel's limit, then the lighter rider will benefit from higher acceleration on the same wheel (provided he is able to match the max torque of the wheel with his technique).

In a hypothetical scenario where two riders of equal height, wheel and body leaning angle/method:
No matter if you are attempting to over-lean and cutout a wheel or if you're just putting these two riders head to head to see who can accelerate faster. If all other things are equal the heavier rider will ALWAYS accelerate faster/win/cutout faster than the lighter rider, even on a hypothetical wheel with no limits.

Over-leaning leading to cut-out is exponentially easier the closer you are to 0% PWM, or the closer you are to 100% PWM.

This means anyone can cut out a wheel if they go fast enough, regardless of body weight (you could potentially be limited by height on the fastest current wheels, as very short people would have a lower center of gravity, and less weight as a consequence, as well.)

On the flipside it's getting more and more difficult and unlikely to over-lean the increasingly higher voltage systems. In the immediate future manufacturers may have to switch the focus to developing a new type of thread for EUC tires to prevent them from skidding out upon over-leaning from 0% PWM. 

Getting 200 and 300V systems could be good for increasing safety in regards to keeping your PWM % low, even with high speeds and low battery. But they don't address the issue of having a single point of contact with the road. I think using knobby tires is already helping prevent a lot of the skidding when aggressively over-leaning from 0% PWM, but at some point (if not already) they have to come up with better tire threads designed for single point contact and explosive acceleration.

If they don't make this tire thread there will always be an upper limit for how much you can Michael Jackson-lean, currently because of the possibility of over-lean leading to cut-out, but in the future when we're past that the upper limit will be a formula including multiple variables: 

1. rider weight 
2. rider height
3. wheel weight 
4. wheel tire thread
5. wheel system (motor, controller, battery cell type, BMS)
6. material and temperature of the road (traction)

Depending on these factors and not much else but wind speed and potentially 1 or 2 more things you'd be able to create a formula to calculate the upper limit of lean for someone with your own personal variables, discovering the upper limits of lean for every PWM % from 0-100. At least with currently used tire thread types in EUC.

 

I don't know... Maybe I'm just going down a rabbit hole that leads nowhere.