The mechanics of the nosedive

[JacoNZ]

Can anyone explain why the onewheel/plus nosedives from the boards point of view? what limit gets breached that cause it to nosedive? What will it take to build a board that cannot nosedive?

[onewheelwraith]

Trying to accelerate to hard while cruising or going up hill. finer angle adjustments are needed to avoid it basically any action that would pull to many amps through the controller or exceed the max motor power limits also I have noticed stability issues when going over bumps that jostle the board enough to upset the gyro' s makes it get wierd for a second

[thegreck]

@JacoNZ A single-wheel device keeps you balanced by moving the wheel in the direction you're leaning in an attempt to stay beneath you (like balancing a broomstick on the palm of your hand). But in order for the spinning of the wheel to propel the board (and you), your weight has to actually be on the wheel (imagine lifting most of the weight of a car off the ground then hitting the gas).

Simply put: if you lean too far forward, and too much of your your weight falls on the front footpad (i.e.: in thin air) the wheel will spin out, but you continue to move forward causing the board to nosedive on your way to the ground.

[JacoNZ]

@thegreck that is a good explanation, thanks.A better stance might then help prevent nosedive, place the front foot as close as possible to the wheel and the back foot further back.

[sonny123]

@JacoNZ

I think at the end of the day, it's the stance you're most comfortable with.
The rule of thumb is to maintain equal balance on both, as if you're on a scale.
It's all in the body's center of gravity over the wheel.

Those who're comfortable getting past pushback are very experienced in maintaining balance without the help of the gyro.

It comes with time.
That's why it's highly recommended to allow it plenty of time even for those experienced snowboarders/surfers/skateboarders.

Onewheel is its own sport.

[scheinoha]

Sorry, if I could actually remember the nose dive I would tell ya :). Happy as hell one munute and split second later BAM. I don't even remember saying "oh shit". I was already looking around while laying in ground
wondering what the heck happened :(.

[JacoNZ]

@scheinoha I know what you mean. It catch you by surprise just when you get too comfortable :-) And it hurts.

[JacoNZ]

Airplanes have stall warnings, just before the wing stalls, there is a loud beep, it warns you to push the nose down\add more power to prevent a stall.
FM should add a nosedive warning to the OW app.

[davew0815]

I just experienced the 'joy' of the nosedive this morning actually twice in a row. I'm pretty new to onewheel and only had my one wheel plus for 2 weeks and ridden it about a dozen times (never ridden the original). I'm an avid wakeboard/snowboarder for 15+ years and ridden boosted and evolve electric skateboards regularly for 2 years. So, I'm new to one wheel but very used to board sports so I picked it up very quickly (or at least thought I did.) Felt very comfortable riding at speed and never had any issues before today. I did very quickly switch the board from 'cruz' to 'mission' because cruz felt terrible...almost immediately putting me into an awkward tail heavy stance when riding with any speed at all. I haven't experienced this problem in mission. Before today, I have mostly ridden close to home. This morning I did a longer ride through my extended neighborhood which is fairly hilly. I got a nosedive the first time right after turning to go up a fairly steep hill. It was going up the hill and seemed to be losing steam then just suddenly nosedived when I pressed into it to keep my speed up. It surprised me and I fell immediately. Decided to take a different route home and went back down the hill. Not one minute later, I noticed a car coming up behind me and I accelerated in an attempt to get around a parked car and pull over out of their way. Exact same thing happened again! This time I was going a little faster but I was also more prepared for it and almost ran it out when I came off. That was maybe worse though as I pulled my hamstring which is my primary injury from the whole ordeal on top of a couple of minor road rash scratches (had helmet and wrist guard on.)

From what I'm reading here it sounds like this is probably due to user error on my part from leaning into my acceleration too much but what I'm struggling with is it didn't seem like I was doing anything different than what I've done on other rides. The fact that I had it happen twice back-to-back like that made me think the motor might have been overheating or something? It was about halfway through on the battery life and I'd been riding pretty hard on it for about 20 minutes. After the second fall, I finished the short ride back to my house at low speed and haven't been on it since. I'm probably out for awhile (from wake boarding as well) as I seemed to have pulled my hamstring pretty good. Icing it right now. I like the one wheel but very frustrated by the falls and injury. I've been riding the electric skateboards for awhile at much higher speeds and have not had any issues. Any have additional tips on how to avoid nosedives or thoughts as to whether or not it might be a faulty board? Someone on this thread mentioned the board spinning out if there is too much weight forward and that makes sense but it certainly didn't feel like that. Felt like the board just suddenly powered off and instantly stopped.

Assuming it is user error any tips on drills or anything to avoid this? Would like to avoid having this happen again.

[sonny123]

@davew0815

Like you, my main pastime was electric skateboard for the 10 years before Onewheel took over.
Had my first nosedive a week into it going uphill.
Honestly, 2 weeks is still kinda new getting a good feel of it.
Many here refer to the nosedive as initiation.
For me, took a good month of easy riding to regain confidence which helped gaining more experience.
I think most of us make the mistake of going a little too fast too soon.
While there've been cases for faulty boards, it's user error most times.
Hope you heal soon and get back Onewheeling.

[iiikz]

@davew0815 Keep in mind that the board is not able to "sense" the terrain and know whether you are on level ground - there is only a certain amount of clearance which allows you to push downward on the front of the board, and when going uphill that clearance is reduced.

Pushing hard (as one might do in order to accelerate quickly) dips the front of the board in the time between the board sensing your lean and it's response with acceleration (the play is also probably a strong function of ride mode). Between the nose dip angle under acceleration, reduced clearance from the hill, and any other clearance reducing items like dips/bumps in the road, it can be easy to catch the front edge when learning the board - especially uphill. Depending on what catches and how the motor is engaged, that's all it takes to send you sprawling.

With time you'll get a better feel for how hard you can push in various situations (I'm definitely still learning!). If you're on a smooth surface, you'll probably also find that edge a little more gently, too, and get to feel the nose hit the ground without catching (totally recoverable).

[davew0815]

Thanks for the replies. So, the nosedive is caused by physically hitting the ground and not by the motor stopping? To me, it felt like the motor just cut out and then the board dropped down, but it happened so fast I can't really say.

I will definitely get back to one wheel when heeled up and will take it more easy. I have fun just carving around cones at the top of my driveway at <10mph so no need to push it to the limits just yet.

[shattle]

@davew0815 Since "nosedive" is not a pre-defined term, it's hard to know what people mean when they say it. When my V2 had technical flaws it turned itself off while I was riding it. The nose augered into the pavement (because I was leaning forward) and I augered myself into the pavement a split second later. I called that a "dead board," because I think of a nosedive as occurring when the rider pushes the motor past its physical ability to maintain level relative to speed/incline. A nosedive can occur at 20 mph or 1 mph, all depending on relative to incline and speed.

[captjack]

I've nosed dived twice so far. Both occurred on smooth flat Florida asphalt.

The first time was a result of accelerating from a dead stop too fast.

The second time I was getting cute and pushing through pushback which resulted in my record speed of 21.73.

The board suddenly seemed to just cut off. I was hurled forward and ran it out a few steps before landing on all fours. It was a nasty wreck but fortunately I wear wrist guards, knee/elbow pads, and helmet.

Of all things, I could have injured I only came out with a bruised heal that took the brunt of the impact.

I learned to respect the pushback from that day forward. I now just enjoy carving at around 10-15mph.

I personally don't think the board in its current state should be taken past 20mph.

[IanJohnson]

While running at speed, the wheel needs to suddenly speed up or slow down as needed to maintain the balance. At low speeds, the motor has plenty of torque available to do that. When riding at high speeds beyond pushback, there is less power available to make corrections for extra weight in the front. It might be able to deal with slight imbalances, but sudden, heavier imbalances like hitting a bump might require a bigger jolt in speed than the motor can provide. This is going to happen at lower speeds when going uphill, because the motor is already taxed.

If you are already going fast, and lean in to accelerate it may no longer be able to accelerate fast enough to raise the nose. It keeps speeding up to raise the nose, and you keep leaning in for more speed until the nose finally hits the ground. If you are going fast, you might be able to go faster still, but you have to accelerate gently. Keep in mind that the further you go beyond pushback, the more balancing becomes your responsibility. If there is a bump, or anything that would cause a sudden forward shift in weight you will need to shift your center of gravity because the board might not be able to do it for you.

[Polle]

@davew0815 Are you on the facebook group of onewheel owners? somebody there made a perfect summary of the different aspects of nosediving.

[crawcraw]

Pure bliss. Just had one Sunday. Don't really recommend it tho. 😉

[davew0815]

@Polle Thanks for the pointer to the Facebook page. I had not seen it (not a big Facebook user). I think I found the post you are talking about and it was very helpful. I'm convinced now that my nosedives were user error. I was doing the things you aren't supposed to do including accelerating too quickly, going too fast as a beginner, and too much weight on the front foot. I felt comfortable and stable while riding ~20 mph but wasn't thinking about the physics or what the one wheel was having to do to keep me stable at those speeds and certainly wasn't prepared for the board to nosedive at any moment. The most useful comment to me in the article was the suggestion to accelerate using mild pressure on the front foot with even weight on both feet rather than shifting weight forward. I'm going to consciously switch to that technique and also slow down a bit in general when I get back on it (which shouldn't be too far away...leg already feels quite a bit better today.)

[Rado]

I've found that the placement of your foreword facing foot can make a big difference. I ride with my front foot pretty close to the wheel. It helps with faster acceleration and less nose diving. I can lean in and my center of gravity is over the wheel and not in front of it. On the plus with the concave foot pads it makes you think you should have a wide stance but if you ride fast and accelerate quickly try bringing your front foot more towards the wheel or just experimenting with your stance and foot placement. My stance changes depending on how I'm riding. Sometimes I'll even change my foot placement while riding. I haven't nosedived in a while since using this type of staggered stance. My rear foot is usually in the middle and I don't hang my toes over the edge. I try to ride on the balls of my feet while still being able to maintain my balance.

[davew0815]

@Rado thanks that's a good tip as well. Yes, I've been riding with a wide stance with both feet at the far end of the board. So, something else for me to change. Leg is feeling pretty good today, I may try hoping on the board again as early as tomorrow and experiment with these changes in stance, weight distribution, etc. (at low speed)