How long is it supposed to take to learn?

[Funky]

5 hours ago, mrelwood said:

Which is exactly what you would’ve learned if you’d have learned to ride first by mounting with supports… 

We will never know.  (But you may be right.) I also learned in "woods" only supports there were trees. You know.. No people around and so on to watch me fail.  

One good thing. I was available to dismount after my first ride.

Edited November 3, 2022 by Funky

[Mono]

On 10/19/2022 at 10:50 AM, rcgldr said:

Similar to a bicycle, but due to different physics, lateral stability occurs around 6 to 8 mph on most EUCs due to camber effect response to lean | tilt of the EUC causing the EUC to self-steer enough to correct for small imbalances, good enough to ride in a straight line. The issue is getting up to a stable speed and being able to stop and dismount.

To my experience, very few beginners are able to ride a straight line at 6-8 mph without side support (or any line at any speed). I have seen dozens of newbies trying, on my wheel and online. The few people who could ride my wheel out-of-the-box first-try had ridden a non-electric unicycle before (out of my head I remember three cases, whereas some other unicyclists also could not do it first-try). A few natural talents (mainly skaters and kids) figured it out in under three minutes which is rather exceptional to all I have seen myself. Usually it takes like 15-45 minutes with individual instruction. Without individual instruction it seems not uncommon to take several hours. This is still quite short compared to how long it takes to learn balancing a non-electric unicycle.

[RayRay]

@johninbaltimore stop reading your own thread...

I'm not saying there's bad advice here, but based on your few brief comments you seem to be overthinking it.

STOP THINKING! 

Edited November 3, 2022 by RayRay

[rcgldr]

7 hours ago, Mono said:

To my experience, very few beginners are able to ride a straight line at 6-8 mph without side support (or any line at any speed).

Although it wasn't needed, I first learned to ride at slow speed, which could have waited until I learned to ride at stable speed. After about 15 minutes of doing beginner drills (rock back and forth, short rides next to fence), at a tennis court, I ventured away from the fence and used arm flailing | yaw steering (flail left to steer right and vice versa), which is instinctive for a lot of beginners, able to do laps around the tennis court on my first attempt, but it involved constant balance corrections. My wife took a video the next day:

https://www.youtube.com/watch?v=zPyy84EThmM

I didn't realize I was hunched over so much until I saw the video, which I corrected afterwards. I then moved to a 600+ foot long straight outdoor parking lot, using two trash bin enclosures 550 feet apart (translates into a 45 second ride at 8 mph) for supported mount and launch, where I found my V8F became stable at 6 to 8 mph, and I no longer had to make any balance corrections if riding in a straight line. Speed control by leaning forwards | backwards wasn't an issue. I then learned to tilt steer (inner foot down, outer foot up), small tilts to see how my V8F would respond, then a weaving pattern, then large radius turns. On day 5 I got free mount on my third attempt after compensating for my only time on a grassy field. My wife took a video on day 10, at night, and from the headlight beam, you can see how stable the V8F become at around 8 mph:

https://www.youtube.com/watch?v=keDvRMScO1g

To improve my tilt steering, I did drills where I would lean, then tilt my V8F inwards enough to straighten back up, doing a weave pattern, learning how to coordinate how much to lean my body versus how much to tilt my V8F depending on speed and turning radius. Low speed tight turns were like learning a new skill, mostly due to the low speed.

The girl in Kuji Rolls video goes through a similar sequence. At first, she's not going quite fast enough to be stable, and uses extended arms for balance. At 8:05 and later into the video, she gradually picks up speed, the V8 she's riding becomes stable and she's able to relax her arms and tilt steer for direction control.

https://www.youtube.com/watch?v=t6o8ZMlo5ko&t=425s

The point of my learning experience, is having learned how to balance at low speed, 3 to 5 mph, using constant correction via arm flailing | yaw steering, I was more aware than most beginners of the transition into a stable | self-balancing mode at 6 to 8 mph where I no longer had to make balance corrections while riding in a straight line. This was before I had even attempted tilt steering. I realized that nothing had "clicked", but instead I was just going fast enough for my V8F to become stable. 

Edited November 4, 2022 by rcgldr

[Mono]

@rcgldr I try to get my head around the stable speed thing and wonder whether any of these points about the relation between camber and stable speed is mistaken?

1. Camber can explain increasing stability with increasing speed for unicycles below the stable speed.
2. The camber stable speed should decrease with increasing tire width.
3. Stability assumes that rider and wheel have always exactly the same side tilt angle.
4. Above the camber stable speed (like above 8 mph on the V8F with a 2.125" tire) the camber results in an overcorrection of deviations (and balancing should become more difficult again).

Do you have a good source to read about camber? So far I only found this Motorcycle Dynamics book by V. Cossalter.

BTW, do you have a leading hypothesis for the cause of speed wobbles of EUCs?

[mrelwood]

I wanted to reply as well while we wait for @rcgldr’s response: (The quoting messes up the numbered list, sorry)

44 minutes ago, Mono said:

1. Camber can explain increasing stability with increasing speed for unicycles below the stable speed.
2. The camber stable speed should decrease with increasing tire width.

Yes and yes, just like in a bicycle.

44 minutes ago, Mono said:

1. Stability assumes that rider and wheel have always exactly the same side tilt angle.

That’s one way of thinking about it.

44 minutes ago, Mono said:

1. Above the camber stable speed (like above 8 mph on the V8F with a 2.125" tire) the camber results in an overcorrection of deviations (and balancing should become more difficult again).

Balancing does not become more difficult from the camber effect overcorrection! Quite the opposite. The wheel becomes so stable that in order to turn you have to lean further to the side than the EUC itself tilts. And even that won’t disturb it’s stability.

 

44 minutes ago, Mono said:

BTW, do you have a leading hypothesis for the cause of speed wobbles of EUCs?

I see cause and catalyst/contributor as separate things. Essentially a wobble is just like a tank slapper on a motorcycle, and is caused by the wheel’s strong tendency to make itself run upright at speed. Which is what the camber effect does.

 But what is the difference on EUCs whether it will wobble or not are the rider’s legs. Tense legs make the resonance of the system stronger, while relaxed legs dampen the resonance.

One example is crouching at speed. The first time you do it, you tense your ankles and legs and let your heels lift up. Sure way to wobble. Then you relax your ankles and feet and let your heels stay on the pedals while crouching: no wobbles!

[Mono]

1 hour ago, mrelwood said:

That’s one way of thinking about it.

It was the only I could come up with that seemed to make sense, after thinking about it more closely. If we decouple wheel and rider tilt, we can always find some way of decoupling that makes the ride stable, AKA as tilt steering to stay balanced.

1 hour ago, mrelwood said:

Balancing does not become more difficult from the camber effect overcorrection! Quite the opposite. The wheel becomes so stable that in order to turn you have to lean further to the side than the EUC itself tilts. And even that won’t disturb it’s stability.

Or, as I interpret the situation, one has to keep the wheel (more) upright at higher speed, because otherwise it would turn too much into the curve and the rider would fly off in the opposite direction (kind-of: it would be unstable). The observation that we need to separate wheel tilt from rider tilt to make the ride stable is to me an indication that it is not stable otherwise.

1 hour ago, mrelwood said:

[...] caused by the wheel’s strong tendency to make itself run upright at speed. Which is what the camber effect does.

In my limited understanding, camber creates a lateral force and a twisting moment which both increase with increasing tilt (=camber) angle and are zero for zero tilt. The lateral force acts opposite to the centrifugal force in a curve, the twisting moment turns the wheel into a curve towards where the wheel is tilted to. I believe the latter was referred to as camber effect in this forum. I don't quite see yet why the twisting force could not destabilize the wheel.

The strong tendency of the wheel to run upright at speed could also be the rider keeping it upright by all means because they intuitively know that they would fly off if they didn't. I am not aware of a camber force acting against tilting the wheel or making tilting more difficult (so little do I know, I think the gyroscopic effect does though).

Edited November 5, 2022 by Mono

[rcgldr]

6 hours ago, Mono said:

as I interpret the situation, one has to keep the wheel (more) upright at higher speed, because otherwise it would turn too much into the curve and the rider would fly off in the opposite direction (kind-of: it would be unstable).

On my V8F with it's skinny 2.125 inch tire, I don't get any sense of a difference in stability from 8 to 18 mph. It's probably just correcting sooner (less tilt) and|or faster (response). I've read that a Z10 with its 4 inch wide tire doesn't feel too stable at around 20 mph, but for some riders it's not an issue. I've also read that 18XL (18 by 2.5 inch tire) feels a bit more stable at speed than a 16X (16 by 3 inch tire), depending on the rider. In videos I've seen of S18s (18 by 3 inch tire) they tend to intermittently get mild wiggles for brief periods, recover on their own, and the riders just ignore it. The momentum in a riders legs and gryo-effects at higher speeds should dampen any over-correcting related response and avoid triggering a wobble. Lower tire pressure reduces tilt response and some riders like Duf, who is so bow legged that he can't touch the upper pads, just the pedals, uses lower tire pressure to avoid wobble and doesn't do stuff like drop off curbs to avoid rim damage at lower tire pressue.

As for how much to tilt in a turn, again due to my V8F's skinny 2.125 inch wide tire, I'm tilting my V8F only slightly less than I lean at 15 to 18 mph. Less tilt is needed for wider tires. Knobby tires need more tilt than street tires. Wrong Way made a video about this:

https://www.youtube.com/watch?v=NsXW4OKnmWc

When riding my V8F, I can take turns using just the pedals without using the upper pads (Duf style), using both upper pads, or just the outer upper pad (mostly if tilting less). 

As an example of how stable EUCs become at speed, the girl in this video slings off a back pack to put her cell phone into the pack, then slings the back pack back on:

https://www.youtube.com/watch?v=Q5HB40I4C3g&t=440s

 

Edited November 5, 2022 by rcgldr

[Funky]

On 11/3/2022 at 9:24 PM, rcgldr said:

Although it wasn't needed, I first learned to ride at slow speed, which could have waited until I learned to ride at stable speed. After about 15 minutes of doing beginner drills (rock back and forth, short rides next to fence), at a tennis court, I ventured away from the fence and used arm flailing | yaw steering (flail left to steer right and vice versa), which is instinctive for a lot of beginners, able to do laps around the tennis court on my first attempt, but it involved constant balance corrections. My wife took a video the next day:

https://www.youtube.com/watch?v=zPyy84EThmM

I didn't realize I was hunched over so much until I saw the video, which I corrected afterwards. I then moved to a 600+ foot long straight outdoor parking lot, using two trash bin enclosures 550 feet apart (translates into a 45 second ride at 8 mph) for supported mount and launch, where I found my V8F became stable at 6 to 8 mph, and I no longer had to make any balance corrections if riding in a straight line. Speed control by leaning forwards | backwards wasn't an issue. I then learned to tilt steer (inner foot down, outer foot up), small tilts to see how my V8F would respond, then a weaving pattern, then large radius turns. On day 5 I got free mount on my third attempt after compensating for my only time on a grassy field. My wife took a video on day 10, at night, and from the headlight beam, you can see how stable the V8F become at around 8 mph:

https://www.youtube.com/watch?v=keDvRMScO1g

To improve my tilt steering, I did drills where I would lean, then tilt my V8F inwards enough to straighten back up, doing a weave pattern, learning how to coordinate how much to lean my body versus how much to tilt my V8F depending on speed and turning radius. Low speed tight turns were like learning a new skill, mostly due to the low speed.

The girl in Kuji Rolls video goes through a similar sequence. At first, she's not going quite fast enough to be stable, and uses extended arms for balance. At 8:05 and later into the video, she gradually picks up speed, the V8 she's riding becomes stable and she's able to relax her arms and tilt steer for direction control.

https://www.youtube.com/watch?v=t6o8ZMlo5ko&t=425s

The point of my learning experience, is having learned how to balance at low speed, 3 to 5 mph, using constant correction via arm flailing | yaw steering, I was more aware than most beginners of the transition into a stable | self-balancing mode at 6 to 8 mph where I no longer had to make balance corrections while riding in a straight line. This was before I had even attempted tilt steering. I realized that nothing had "clicked", but instead I was just going fast enough for my V8F to become stable. 

The first video. It literally was my (Doh without any gear..), same riding i did my first time, when wheel started to move forwards. I also used my hands to "balance". Like i said before - i "tried" to free mount the wheel till i could. Then i started to ride. For my it somehow worked out. In those 3 days while trying to mount it, i learned to "balance" in place. (I'm still so angry at myself for not leaning forwards enough.) If i did that faster, i would have been riding a lot sooner.

And the second video. Was me 2 weeks later when i bought my personal wheel. (I learned on my dad's wheel. When i learned to mount/ride it "somewhat". I didn't ride his anymore. Whole time spent on that wheel while "learning" was about ~5 hours together.) After getting my own wheel - first day i tried it out in woods, where there were no people around. The second day i was already riding true city. I won't lie, i still dropped my wheel time to time. Like i could not break in time and it hit "bigger" curb - i still was afraid going over curbs. And i simply run off the wheel as it flop on ground.. (I had the wheel packed in white shower mat and duct taped around.. It looked goofy, but protected the wheel for the first week.) Over all while i was still learning, but same time riding true people in city, i dropped it maybe 6? times. Each time was at slow speed while stooping. I put my feet on ground to fast. And it went off on my. Later i started to do the 2-3 hops to stop. If i place my feet on ground to fast, i simply did 2-3 one legged hops forwards.  But over time i stooped to do the hops. As i learned to perfectly stop. And control my wheel one legged. 

It literally was the second day, after i was available to go forwards on my dad's wheel. I simply rode true city. And learned over time. I didn't go to "empty" places. Won't lie - i struggled at times. But because i wasn't riding true empty smooth/flat fields. - I learned "faster". I had to go over curbs, i had to watch out for people and potholes. I had to ride at walking speeds - All that the second day i choose to go into city. Maybe that's why i learned "faster". Because i had challenges.

Or maybe it was the 2 weeks i didn't ride, before getting my own wheel. While sleeping it somehow "helped".  You know.. Sleep learning. 

 

Ohh have you tried simply turning your wheel left~~/~~right at very, very slow speeds? Like if you would use your hands, but instead using only wheel. Your upper body stays in center. Not using hands at all for balancing. (You can hear the rubber even scraping the ground.. Because you are going left~~/~~right motion. That's how slow you go.) I call that the old granny riding speed.  You know.. When you ride to an older people and politely ask them to let you pass. <3 And if they suddenly stop. I'm ready to put my feet down and also stopping.

Edited November 6, 2022 by Funky

[rcgldr]

4 hours ago, Funky said:

I also used my hands to "balance".

Arm flailing | yaw steering is often taught to beginners for pedaled unicycles, probably due to slower speed, and having a seat limits how much a pedaled unicycle can be tilted. For EUC, it seems most of the how to ride videos emphasize getting enough speed to be stable, and although you see beginners using extended arms for balance, it's usually not mentioned in those how to ride videos.

4 hours ago, Funky said:

And the second video.

The first part of that video where I'm going straight is pretty much what I discovered on my 3rd day when I switched to the long straight, other than I was using support to mount and launch. I waited until day 5 to free mount. My turning via tilt steering was improving each day though.

 

4 hours ago, Funky said:

have you tried simply turning your wheel left~~/~~right at very, very slow speeds?

That still requires momentum. The same torque use to twist the wheel in one direction will twist the rider's upper body in the other direction if the rider doesn't build up momentum first. One way to set this up while riding straight is to tilt the wheel inwards while twisting upper body inwards, then using upper body momentum to twist the wheel inwards. I've seen a video of a very tight u-turn done using this method, with the rider also leaning backward as well as twisting upper body to setup the u-turn before doing the u-turn.

 

4 hours ago, Funky said:

stopping

That wasn't an issue for me. As seen in the first video, I was grabbing my V8F rather than hopping with one leg, but by day 3 I was stopping and stepping off without having to grab the wheel most of the time, and almost all the time by day 10 as seen in the second video. I sometimes practice stopping and stepping off with the other foot, but it doesn't feel as comfortable. 

 

[Mono]

@rcgldr I thought you meant by "stable" that no steering input is needed for balancing (like what I understand here). Did I misunderstand this?

16 hours ago, rcgldr said:

Lower tire pressure reduces tilt response

This is funny given that there is also zero tilt response when the contact patch is a single point and lowering the pressure increases the patch size. I am a little curious how the response vs patch size curve looks like.

16 hours ago, rcgldr said:

When riding my V8F, I can take turns using just the pedals without using the upper pads (Duf style), using both upper pads, or just the outer upper pad (mostly if tilting less). 

Just the inner pad works too, I just learned on one leg to turn in the direction of the leg I stand on. To my surprise, there tends to be comparatively little pressure on the pad when only standing on the inner leg. I suspect that pretty much everything I can do standing on both feet not touching the pads I can also do on one leg (up to different limitations by muscle strength and forces on the structure), at least in principle. I'd be interested if you can see a candidate counter example.

BTW, I suspect you overlooked my questions above (because you didn't answer any of them)? I admit they are a little off topic.

Edited November 6, 2022 by Mono

[Funky]

2 hours ago, rcgldr said:

Arm flailing | yaw steering is often taught to beginners for pedaled unicycles, probably due to slower speed, and having a seat limits how much a pedaled unicycle can be tilted. For EUC, it seems most of the how to ride videos emphasize getting enough speed to be stable, and although you see beginners using extended arms for balance, it's usually not mentioned in those how to ride videos.

Yeah it is only natural to use hands to help keeping balance.

2 hours ago, rcgldr said:

The first part of that video where I'm going straight is pretty much what I discovered on my 3rd day when I switched to the long straight, other than I was using support to mount and launch. I waited until day 5 to free mount. My turning via tilt steering was improving each day though.

I really didn't have any problems riding.. The first time wheel started to move forwards. I was already riding the same way you did in the video. And because i had already learned to free mount the euc before riding. Afterwards it just got easier each ride.

2 hours ago, rcgldr said:

That still requires momentum. The same torque use to twist the wheel in one direction will twist the rider's upper body in the other direction if the rider doesn't build up momentum first. One way to set this up while riding straight is to tilt the wheel inwards while twisting upper body inwards, then using upper body momentum to twist the wheel inwards. I've seen a video of a very tight u-turn done using this method, with the rider also leaning backward as well as twisting upper body to setup the u-turn before doing the u-turn.

I don't really know what i do - to "do" what i'm doing. I simply do what feels natural. I don't think about how i'm doing it.  

For u-turns where you got about your shoulder width space to turn around - i simply use my feet. I place my non dominant feet on ground and keep riding with euc. I like doing those U-turn the best. Because i keep riding forwards it turns me around. 180 degree almost completely in spot. (1 feet on ground 1 feet on euc.)

But if i got about arms length of space to turn around i lean my wheel so much sideways, that pedals touch the ground sometimes. When i'm riding my dad's euc, he has the pedals a lot lower to the ground. I can't turn on his wheel that well - because i'm scraping pedals like crazy. I once even landed on pedal so hard that i turned around on pedal itself.  Wheel even speed up as it lost contact with the ground. That was fun. It's always awkward going back on "smaller" euc. It needs less input of the user.. Less power and so on.

2 hours ago, rcgldr said:

That wasn't an issue for me. As seen in the first video, I was grabbing my V8F rather than hopping with one leg, but by day 3 I was stopping and stepping off without having to grab the wheel most of the time, and almost all the time by day 10 as seen in the second video. I sometimes practice stopping and stepping off with the other foot, but it doesn't feel as comfortable. 

Yeah i was already trying to do that the first day i started to ride. Sure time to time i still used my hands to catch the euc. Because i knew it will fall otherwise.. But more or less i tried to use only my leg to hold the euc. Hands of the device much as possible. That's why i dropped it so many times - if you think about it now.  

 

It's worth learning to mount/dismount with your other feet also. - That way you can "walk" on the euc while riding. By "walk" i mean you can lift/move your feet around while riding. It helps also if you mount the euc by not looking at it and you need to "fix" your feet position. Stepping off i can do with any feet without any issue. Mounting is much harder with my other leg.

Also one leg riding is still pretty hard on my non dominant leg. Because of that - i still can't completely/freely move my dominant feet around on pedals while riding.

Edited November 6, 2022 by Funky

[Paul A]

Practice EUC with brush mounted

Jason W.

147 subscribers

Oct 31, 2022

 

 

 

[rcgldr]

On 11/5/2022 at 5:38 AM, Mono said:

1. Camber can explain increasing stability with increasing speed for unicycles below the stable speed.
2. The camber stable speed should decrease with increasing tire width.
3. Stability assumes that rider and wheel have always exactly the same side tilt angle.
4. Above the camber stable speed (like above 8 mph on the V8F with a 2.125" tire) the camber results in an overcorrection of deviations (and balancing should become more difficult again).

Do you have a good source to read about camber? So far I only found this Motorcycle Dynamics book by V. Cossalter.

BTW, do you have a leading hypothesis for the cause of speed wobbles of EUCs?

1 - camber effect is a response to tilt. A tilted tire is somewhat like a section of a cone and will tend to turn in a circle.

2 - true if the other factors are similar (a wider knobby tire may not respond as well as a skinnier street tire).

3 - Once in stable mode and riding in a straight line, the lean and tilt angles will be small. If lean and tile angle are the same, then at sufficient speed, an EUC will become stable, but for lean and tilt angle to be exactly the same, the rider's legs would need to be relatively rigid. Most riders legs are bent at the knees, but otherwise somewhat relaxed to allow some tilt movement of the EUC that is more or less than the rider's lean angle. Even with relaxed legs, an imbalance will exert a torque onto the pedals in the direction of imbalance, causing the EUC to turn in the direction of imbalance and tend to turn so that contact patch remains under the center of mass. At a stable speed, any imbalance is caught quickly enough there's no sense of constant correction. Looking at my second video, the headlight beam is has almost no wiggling once I'm at stable speed on my V8F.

4 - Assuming the riders legs are reasonably relaxed, then the torque on the pedals is countered by the torque related to lateral (turning) acceleration, and the end result is stability occurs over a range of speeds. As posted before 8 mph and 18 mph feel the same on my V8F if riding in a straight line, while actual turning requires less tilt at higher speed. At higher speed, there is less tilt angle and|or shorter duration in stable mode, and the riders legs, and if sufficient speed, gryo effects dampen out over-correction.

Camber - camber thrust is different than camber effect. Camber thrust is related to the amount of inwards contact patch flexing due to lateral loads while turning. Camber effect is a single tire that turns when tilted. Motorcycles don't experience camber effect because camber effect at the front tire would require the rear tire to slide outwards, and vice versa.

Wobbles - normally triggered by some disturbance, or a tire than is not rolling exactly straight or has uneven distribution of weight. I only get mild wobbles when braking hard. Lower tire pressure causes the contact patch to become flatter and flex more, so there is less camber effect response to tilt.

Counter-steering that some (most?) riders are unaware of. In order to lean to the side, a person has to initially exert more downwards pressure on the outer foot. On the ground, this directly causes a person to lean, while on an EUC, that pressure causes the EUC to tilt outwards and turn outwards from under the rider, leaning the rider inwards. There's no need to focus on pedal pressure, just leaning. Similarly, if a rider is trying to remain vertical at less than stable speed, if the rider starts to lean, the pedal pressure the rider applies when trying to return to vertical works because it causes the EUC to turn back under the rider.

Edited November 7, 2022 by rcgldr

[Mono]

2 hours ago, rcgldr said:

Camber - camber thrust is different than camber effect. Camber thrust is related to the amount of inwards contact patch flexing due to lateral loads while turning. Camber effect is a single tire that turns when tilted. Motorcycles don't experience camber effect because camber effect at the front tire would require the rear tire to slide outwards, and vice versa.

Wikipedia writes: The net camber thrust is usually in front of the center of the wheel and so generates a camber torque, twisting torque, or twisting moment. The orientation of this torque is such that it tends to steer a tire towards the direction that it is leaned. An alternate explanation for this torque is that the two sides of the contact patch are at different radii from the axle and so would travel forward at different rates unless constrained by friction with the pavement.

I fear we are discussing here at the cutting edge of human knowledge or even beyond. I guess that's a good time to let it go 

[rcgldr]

3 hours ago, Mono said:

Wikipedia writes: The net camber thrust is usually in front of the center of the wheel and so generates a camber torque, twisting torque, or twisting moment. The orientation of this torque is such that it tends to steer a tire towards the direction that it is leaned. An alternate explanation for this torque is that the two sides of the contact patch are at different radii from the axle and so would travel forward at different rates unless constrained by friction with the pavement.

To clarify my prior comment, an EUC turns in direct response to camber effect (or yaw | twisting). A motorcycle turns because the front tire is steered inwards of the direction of the rear tire. Camber effect is one of the components that generates an inwards steering torque onto the front tire. Camber effect at the rear tire has almost no effect, since the inwards torque would be applied to the entire motorcycle, resulting in a very small inwards torque exerted on the front tire.

A small component of inward steering torque on the front tire is due to camber effect. Another small component is a camber thrust in front of the middle of the contact patch. The main component of the inwards torque is due to trail, the contact patch is behind the imaginary extended pivot axis of the front forks, causing the pavement to push up at the contact patch behind the pivot axis (unless the amount of trail is very small). Braking at the front tire while leaned exerts a backwards force onto the contact patch, which is offset to the inside of the tire, and depending on the tire, this result in more inwards torque than the other components. The combined effect of these inwards steering torques is to cause the front tire to over-correct, steering inwards enough to straighten up the bike, so a rider has to exert an outward torque onto the handle bars to oppose this over-correcting response. Again an example of counter-steering, if vertical, steer outwards to lean inwards, if leaned, steer more inwards to lean less, steer less inwards to lean more. I ride a 2001 Suzuki Hayabusa motorcycle, and have to apply a continuous counter-steering outwards torque on the handlebars in order to hold a lean angle in addition to the normal counter-steering inputs needed to change lean angle. At higher speeds, gyro effect dampen the self-correction response, and at very high speeds (100+ mph), the stability effect transitions into holding the current lean angle as opposed to tending to return to vertical.

EUCs also need to be counter-steered to change lean angle, although in most cases, the foot pressure that a rider would use to lean while standing on the ground will cause an EUC to counter-steer outwards from under the rider and lean the rider inwards. Most of the time, a rider can just focus on leaning rather than focus on pedal pressure inputs, for turning, accelerating, and braking.

Stability - in the case of a motorcycle, a gusting crosswind applies a lateral force onto the bike, and due to trail, this causes the front tire to steer downwind, steering the tires downwind of the rider, causing the bike to lean into the wind automatically. There's a limit to this and if the gust is very strong, the rider will have to exert additional downwind torque on the handlebars to further lean into the wind. An EUC doesn't have this trail effect, but if the rider just attempts to lean into the crosswind, the rider does this by applying more downwards pressure on the downwind pedal, causing the EUC to steer outwards from under the rider, leaning the rider into the crosswind. So unlike a motorcycle, an EUC doesn't have the automatic crosswind stability of a motorcycle.

 

Edited November 7, 2022 by rcgldr

[mrelwood]

 

On 11/5/2022 at 4:08 PM, Mono said:

Or, as I interpret the situation, one has to keep the wheel (more) upright at higher speed, because otherwise it would turn too much into the curve and the rider would fly off in the opposite direction (kind-of: it would be unstable).

The self-correcting nature of a tubular tire makes it stay upright by itself, there’s no need for the rider to do anything to keep it upright. And the tilt angle and turn radius are (somewhat) linearly linked. So the rider can’t decide how much to tilt the wheel in a specific turn, one has to tilt as much as the curve dictates. And a wheel with a 3” tire is stable enough at speed that you can even do all kinds of ill advised movements on it, yet it is so stable that you’ll stay on without a problem, and the wheel’s trajectory ID barely affected at all.

 When the rider leans further to the side than the wheel, the rider is doing so in an attempt to tilt the wheel to the side. But the wheel is so stable that the rider has to go this far to get it to tilt. Zero attempt to “keep” the wheel upright required.

 

 Gyroscopic forces become apparent at a later stage, not usually under 30mph. And it will oppose any change in the tilt angle, getting back to vertical as well.

 Everyone who has ridden an EUC with a 3” tire past 10mph knows that the tilting behavior and the tendency to stay vertical at speed are automatic and quickly become natural and predictable. One doesn’t have to think about the tilt or the turn radius at all.

 In fact, theorizing over this before it becomes natural is a hindrance to learning! If you start to think about it at all, your focus is in the wrong place and your learning will be hindered.

 

On 11/5/2022 at 4:08 PM, Mono said:

The strong tendency of the wheel to run upright at speed could also be the rider keeping it upright by all means

Plenty of riders doing that on a daily basis, no need for guesswork. 

[Mono]

3 hours ago, mrelwood said:

When the rider leans further to the side than the wheel, the rider is doing so in an attempt to tilt the wheel to the side. But the wheel is so stable that the rider has to go this far to get it to tilt

I don't believe that for a second. Camber forces do not change the ease with which the rider can change the wheel tilt. Gyroscopic forces do, but we seem to agree that they do not determine the tilt angle of the wheel when riding curves.

We agree that wheel tilt determines the radius of the curve. However in my world, wheel tilt is a rider input (the rider can decide the radius of the curve), not a forced output of the system (where the radius is a given and then forces the wheel into a certain tilt).

Now, riders lean the more to the side the faster they go because for a given curve radius the centrifugal forces increase with speed, whereas the tilt angle of the wheel has to stay constant for a given radius.

Edited November 7, 2022 by Mono

[mrelwood]

5 hours ago, Mono said:

I don't believe that for a second. Camber forces do not change the ease with which the rider can change the wheel tilt.

Doesn’t leaning further away from the wheel center count as being less easy, as it requires more effort?

5 hours ago, Mono said:

We agree that wheel tilt determines the radius of the curve. However in my world, wheel tilt is a rider input (the rider can decide the radius of the curve), not a forced output of the system (where the radius is a given and then forces the wheel into a certain tilt).

Of course, that’s obvious.

5 hours ago, Mono said:

Now, riders lean the more to the side the faster they go because for a given curve radius the centrifugal forces increase with speed, whereas the tilt angle of the wheel has to stay constant for a given radius.

I think we are saying the same thing, only that we look it from a different perspective. I say the wheel is harder to tilt at speed, you say the rider must lean further to tilt. To me they are the same thing.

Btw, I noticed you only mention 2.125” or narrower EUCs in your profile. Have you had the chance to ride a 3” EUC for a notable amount of distance?

Edited November 7, 2022 by mrelwood

[Mono]

3 hours ago, mrelwood said:

I think we are saying the same thing, only that we look it from a different perspective. I say the wheel is harder to tilt at speed, you say the rider must lean further to tilt. To me they are the same thing.

Not quite, because I say the rider must lean further in order to cancel the centrifugal force acting on their body (and on the wheel), not in order to tilt the wheel. Having said that, the centrifugal force on the wheel should indeed create a roll torque which the rider indeed has to push against to prevent the wheel from getting upright. That is because in a continuous turn where the rider leans more than the wheel, the wheel alone is not in a neutral tilt position with respect to the centrifugal force because rider+wheel are.

 

3 hours ago, mrelwood said:

Btw, I noticed you only mention 2.125” or narrower EUCs in your profile. Have you had the chance to ride a 3” EUC for a notable amount of distance?

I only had some short encounters with 3" tires but I have been riding on a 2.5" wide tire for more than a thousand km.

Edited November 7, 2022 by Mono

[rcgldr]

21 hours ago, mrelwood said:

The self-correcting nature of a tubular tire makes it stay upright by itself, there’s no need for the rider to do anything to keep it upright. And the tilt angle and turn radius are (somewhat) linearly linked. So the rider can’t decide how much to tilt the wheel in a specific turn, one has to tilt as much as the curve dictates.

When the rider leans further to the side than the wheel, the rider is doing so in an attempt to tilt the wheel to the side. But the wheel is so stable that the rider has to go this far to get it to tilt. Zero attempt to “keep” the wheel upright required.

 

11 hours ago, Mono said:

Not quite, because I say the rider must lean further in order to cancel the centrifugal force acting on their body (and on the wheel), not in order to tilt the wheel. Having said that, the centrifugal force on the wheel should indeed create a roll torque which the rider indeed has to push against to prevent the wheel from getting upright.

A rider tilts a wheel by applying an inwards torque on the wheel, more downwards pressure on the inside pedal and|or more pressure on the outer upper pad. There's a Newton third law pair of torques: rider exerts inwards torque onto wheel, wheel exerts outwards torque onto the rider. So the rider needs to be leaning inwards in order to exert an inwards torque onto the wheel (otherwise the rider would end up leaning outwards). Just like a motorcycle, a rider needs to lean inwards to compensate for centrifugal reaction force, then turn, counter-steering. The rider initially exerts an outwards torque onto the wheel, the wheel exerts an inwards torque on the rider, and the outwards torque on the wheel causes it to steer outwards from under the rider, causing the rider to lean inwards. A rider can mostly just focus on leaning, because it's very similar to leaning on the ground, to lean inwards a person exerts more downwards force on the outer foot. On an EUC, a rider has to coordinate how much to lean and how much to tilt the EUC. With a wider tire, at higher speeds, the rider tilts the EUC less than the rider leans, as seen in this clip from Wrong Way's tires and turning video, where the middle screen shows a Z10 with its 4 inch wide tire tilted the least, and the knobby tire on the right tilted the most:

https://www.youtube.com/watch?v=NsXW4OKnmWc&t=314s

To clarify my prior point about self-stability which occurs at sufficient speed when riding in a straight line, there's no need for tilt and imbalance lean angle be the same. Assuming initially equal pressure on pedals and upper pads, any imbalance will end up creating a torque on the wheel in the direction of imbalance, causing the wheel to steer into the direction of imbalance to regain balance. My wife took a video of me on my V8F riding on a cambered street (sloped inwards towards the middle for drainage), which affects the relative tilt angle, yet it feels just as stable as if riding on a level surface.

https://www.youtube.com/watch?v=yjD9sWQHoSA&t=7s

In this tram tracking clip from Wrong Way's tires and turning video:  he shows a Z10 with it's 4 inch wide tire on a very cambered surface, and it's difficult, but with a 2.5 inch wide tire or a knobby tire, the riding is mostly normal. Even with the Z10, the wheel is making corrections much faster than Wrong Way could react, so there's still some self-stability, although he's extending his arms for additional balance.

https://www.youtube.com/watch?v=NsXW4OKnmWc&t=470s

Even with tram tracking while riding in a straight line, there's some some of the self-correcting response at play. The immediate response to a transition onto a cambered surface creates a relative tilt angle that momentarily steers the wheel up-slope from under the rider (momentarily leaning or offsetting the rider down-slope), but that results in an down-slope torque on the wheel and brief correcting response, resulting in the path straightening out and the wheel angled slightly down slope, depending on tire parameters, and the wheel ends up going in a straight line if the tram tracking is reasonably mild.

Edited November 8, 2022 by rcgldr

[Mono]

It dawns me that I'd like to see this self-stabilizing behavior with someone on who has never learned to ride an EUC or unicycle 

[plentora]

3 hours ago, Mono said:

It dawns me that I'd like to see this self-stabilizing behavior with someone on who has never learned to ride an EUC or unicycle 

Self-stabilizing needs speed which means without EUC skills you cannot establish it. Speed increases stability for sure.

Beginners "problems" (which are actually natural to humans):

- Riding too stiff / being too tense (perfectly normal at first) -> amplifies oscillations

- Riding too slowly -> very minimal self-stabilizing effect and you need to constanly balance

 

Carving / slaloming is harder the faster you ride. I believe this is because the wheel "fights" against turning.

[rcgldr]

4 hours ago, Mono said:

It dawns me that I'd like to see this self-stabilizing behavior with someone on who has never learned to ride an EUC or unicycle 

How about a dog? The EUC corrects to regain balance as the dog moves, then it straightens up once the dog stops moving:

 

[plentora]

Self stabilizing example:

 

at 14:41