I went too fast on my V5F+

[nomad]

After some extreme pain in my now swollen wrist and spending 6 hours in the hospital waiting room, I think I've now now learnt all the limits of this wheel the hard way.. Luckily no fractures showed on the x-rays! It seems I'll be fully recovered in a few weeks. Two days later now it doesn't hurt that much anymore, I'm already getting back some range of motion in my hand, I can at least grab things and use it carefully, so I think it will be totally fine!!

 

I usually accelerate right up to 23 km/h, this is where the tiltback starts pushing back, so I ease off and keep cruising at 22 km/h. But it was different this time, I did as usual but before the tiltback could push me back it gave up and folded instead. I managed to run two and a half steps but the speed was just too high this time! I have run off successfully before more than once at 23-25 km/h, this was definitely faster. I was wearing snowboard gloves with wrist protection rails built-in because it's very cold! The gloves are warm and comfy but unfortunately they don't protect as good as my standard ennui city braces. (Those last mentioned wrist guards even saved my wrists falling hard at 45 km/h, it's on Youtube "Msuper v3 top speed crash", no hospital visit that time).

I estimate this fall was about 27-28 km/h, I did not have any speed measuring app running to say exactly. Battery level was around 55%. Ambient temperature was around 0°C. While I went into a shop for a minute I left the wheel outside.. So then I step on again and start accelerating, not super hard but still pretty hard as usual. I'm on a car road totally smooth, no cars, I was only going about 50-100 meters to another shop, maybe I should have used the trolley instead.. Anyway I keep gaining speed steadily then I felt a relatively weak tiltback comes on, so I try to ease off the pressure like usual.. But it happened too fast to react, pedals are going down.. It's loosing speed falling behind, torque is drained out, it's definitely folding, it's not technically cutoff I can feel some torque left when I push away to run! I know how it feels, this is the third time on this wheel but I get back to that..

After one or two weeks owning the wheel I installed the app and adjusted the pedals to tilt -3° forward. This seemed to make the tiltback somewhat less aggressive and more comfortable to ride against it. Many have commented they like a -3° setting and I do too as on this wheel 0° does not seem horizontal for some reason. I think the tiltback might start very softly around 20 km/h already, as when using the trolley and when riding slower it does indeed tilt forward with a -3° setting, logically enough.. But at 22 km/h it's horizontal and stable, I guess one is already riding on some tiltback at this speed then.. I've always been cruising at 22 km/h on this wheel literally since day one. A couple of days ago I thought I would try something out.. I adjusted the pedal tilt to -8° which is the max value allowed in the app. Doing this it's possible to cruise constantly at 24-25 km/h with horizontal pedals. Oh yeah! speed as advertised at last.. I ordered a 25 km/h wheel and damn it that is what it will do lol. As it turns out this can be a bad idea!! In fact I think anything above 22 km/h might not be the best idea on any single wheel without any redundancy, but that's another discussion...

I have 3475 km mileage now on this wheel so this was not your typical newbie overlean.. I have clearly overleaned it two times before, first time when trying to show off the amazing accel performance, I had to run off at 15-20 km/h, the wheel folded and bounced straight up in the air behind me.. That happened in my first weeks so that was a true newbie mistake. Second time was a couple of months later it was very slow but still painful, about 5km/h.. I accelerated way too hard out of a hairpin turn (to show off..). I was still turning when it folded so I fell to the side and hit my thighbone pretty hard, it was sore for days, could not sleep on that side... Also hurt my foot a little but nothing serious. Since then I'm more careful with pushing for acceleration out of turns! This time I guess I was showing off again, but not so much really! It's just that the speed was higher...

By the way all these falls and all other crashes I've had all happened on my free time, never when commuting to/from work, which I've been doing for half a year now without any problem! So it's been 100% safe for regular commuting. However I was actually very close to a cutoff once when commuting, because I accelerated very hard from standstill on low battery, I felt the pedals suddendly go soft they dropped down way too fast. I immediately pushed back but it's scary how fast and how far down they tilted, that was the only time ever I managed to save a cutoff and it was around 10 km/h so it probably wouldn't have mattered as a run off could be done.

Now this was the first time it failed without me doing any extreme manouver. And I actually feel that the wheel (or the app actually) can partly be blamed for this, not only myself. The app should not allow tilting it forward this much by simply dragging a slider. Sure I did push it hard this time but I'm pretty sure it would not have happened with 0° or even my standard -3° tilt setting at all! Trying to go through the tiltback 'curve' at 23-25 km/h (more like a tiltback 'wall' really) feels like the pedals point to the sky and it takes a lot of effort, you basically reach 26-27 km/h tops for only a second or two with extreme tiltback. But with the -8° I reached at least 27-28 km/h smoothly with relatively little effort as there was no strong tiltback.

I think the reason for the weak tiltback must be because there's too little power left over for any stronger tiltback at that speed. And the power boost tiltback needs might have consumed the rest of the power, instead of using the power to only keep up speed and balancing. And maybe the max tiltback angle is not so steep after all when starting from -8°. On top of that, with these motors when speed goes up the torque goes down! But I did push pretty hard so it could also be that the battery peak power was not enough. The point is if you ride at higher speed constantly, when you eventually hit some unpredicted bump, it won't have enough power! I advice the pedal tilt setting should be used with caution, obviously.. You may get away with -8° for a while but it is not very safe I just give this warning! I've had no issues with a -3° setting so now I've set it back to that myself.

[houseofjob]

@nomad hope you heal well, and thanks for the report.

some thoughts:

• personally, I'm way more cautious with battery level in winter temperatures. battery percentages shrink much faster in cold, so I am constantly charging back up to 95-100%, even if I don't need. in general, an EUC at 100% and an EUC at 55% are not the same performing machines, but this is tenfold in winter cold. 
• I also ride my V5 with pedals slightly aligned down, but not -3º, probably more like -1º, like you said, to compensate for the early and long gradual tiltback. but you can't over-do it, regardless of any EUC. I tried to do the same on an IPS Zero 340WH, and at low speed, the EUC cutout. can't explain the exact reason, but it feels like aligning the pedals noticeably down significantly interferes with the gyroscope's job of both balancing and responding to body weight lean.
• FWIW, current Gotway EUCs cannot set their tiltback too high, or they get cutout. We tend to underestimate the power demand of tiltback, I believe. If you run the EUC well past max speed, demands become too much, both speed and tiltback (and just because you adjusted pedal angle and cannot feel tiltback angle doesn't mean it isn't using significant power and tilting back)

 

[Mono]

2 hours ago, nomad said:

I think the reason for the weak tiltback must be because there's too little power left over for any stronger tiltback at that speed. And the power boost tiltback needs might have consumed the rest of the power, instead of using the power to only keep up speed and balancing.

I agree with your reckoning that the probable main cause was the incompatibility between the extreme horizontal pedal adjustment and the standard tiltback, in that the pedal adjustment undid the tiltback effect. Tiltback itself just changes the neutral target angle of the pedals, that is, the angle which induces neither acceleration nor deceleration. Just as the neutral target angle you have changed in the app for low speed, but speed dependent. AFAICS, the change of the neutral angle doesn't require any power in itself, nor is it more energy demanding to ride with a different angle. In other words: the belief that tiltback is power demanding is probably a myth, maybe fuelled by the impression that riding under tiltback is exhausting.

I experienced another glitch in the InMotion app: one can change the tiltback speed while riding. This gives a rather surprising effect when changing the speed below the current speed, which is indeed possible and becomes effective immediately. Well, it should not!

[nomad]

1 hour ago, Mono said:

I agree with your reckoning that the probable main cause was the incompatibility between the extreme horizontal pedal adjustment and the standard tiltback, in that the pedal adjustment undid the tiltback effect. Tiltback itself just changes the neutral target angle of the pedals, that is, the angle which induces neither acceleration nor deceleration. Just as the neutral target angle you have changed in the app for low speed, but speed dependent. AFAICS, the change of the neutral angle doesn't require any power in itself, nor is it more energy demanding to ride with a different angle. In other words: the belief that tiltback is power demanding is probably a myth, maybe fuelled by the impression that riding under tiltback is exhausting.

I experienced another glitch in the InMotion app: one can change the tiltback speed while riding. This gives a rather surprising effect when changing the speed below the current speed, which is indeed possible and becomes effective immediately. Well, it should not!

If the pedals were mounted up at the wheel axle then tiltback would need less power. But the pedals hang lower down under the axle on support arms. This means it has to lift up the rider somewhat if the pedal arms are not hanging straight down. The longer the pedal arms are the more power is needed to lift the pedals. But also more power is needed from the rider to tilt the pedals so hitting bumps for example will have less tilting effect with a longer pendulum. So a 22" or 18" wheel will 'swing' less than a 14" wheel. Plus a bigger wheel diameter will roll over the same bumps easier, that's why the bigger wheels are so stable offroad.

In order to rotate the pedal arms it has to change the speed of the motor. This definitely induces acceleration or deceleration! There is no way it can apply tiltback without accelerating the wheel. As these two parts are moving in relation to each other. The pedals are not on a separately controlled axle. In the case of tiltback, wheel acceleration is the only way.

You can see what happens when you change the pedal tilt angle with the app. Either the wheel rolls on the ground (this means speed was changed from 0 km/h). Or if the wheel (motor) does not roll on the ground, then the chassis/pedals (stator) rolls instead. There's really nothing else that can happen when the pedals are hard mounted to the stator. You are standing on these pedals mounted to the stator, if you push down and do not want the stator to just roll forward, then the motor better do it instead, or what will happen?

What you are doing when you push the pedals forward is that you are accelerating the stator, the acceleration you apply must then be countered by accelerating the motor in the opposite direction. You can call it that the pedals are held in position by torque. But as you change the angle it has to rotate it back to position = acceleration.

[Mono]

I am not sure I got your point  I agree that if the driver keeps the pedals level under tiltback, the wheel will accelerate.^1 Of course when I am saying tiltback is energy neutral, I assume the driver adjusts to the tiltback (i.e. lifting the forefeet accordingly) such that speed doesn't change. If the driver slows down one could argue tiltback is energy saving. On the other hand, the driver is unlikely to speed up when tiltback sets in, but see ^1. 

17 hours ago, nomad said:

This means it has to lift up the rider somewhat if the pedal arms are not hanging straight down.

Or it means the driver has to lift their forefeet. Given most of the weight is on the heels, this could even mean the rider will be "lifted" down. In any case, it seems that the lifting work will be done by the rider, not by the wheel.

^1 Deceleration is usually initiated by accelerating the wheel (not the rider) such that the wheel moves in front of the CoG of the driver+wheel mass. This is why tiltback is effective for slowing down. This initial acceleration of course costs energy, but the mechanism can be initiated and controlled by the driver irrespectively of tiltback and its energy costs are independent of the neutral target pedal angle, i.e. of the tiltback.

[Gareth Tibit]

Very Vivid description. I have the normal v5f, not the + and I push it to average 27-28km/h all the time with my 55kg light ass. Seems I'm gonna turn it down a notch after this...I do have an mcm4hs 340 I haven't rode and since I got the v5f I abandoned the old wheel. Perhaps the v5f series aren't built for fast rides

[nomad]

18 hours ago, Mono said:

I am not sure I got your point  I agree that if the driver keeps the pedals level under tiltback, the wheel will accelerate.^1 Of course when I am saying tiltback is energy neutral, I assume the driver adjusts to the tiltback (i.e. lifting the forefeet accordingly) such that speed doesn't change. If the driver slows down one could argue tiltback is energy saving. On the other hand, the driver is unlikely to speed up when tiltback sets in, but see ^1. 

Or it means the driver has to lift their forefeet. Given most of the weight is on the heels, this could even mean the rider will be "lifted" down. In any case, it seems that the lifting work will be done by the rider, not by the wheel.

^1 Deceleration is usually initiated by accelerating the wheel (not the rider) such that the wheel moves in front of the CoG of the driver+wheel mass. This is why tiltback is effective for slowing down. This initial acceleration of course costs energy, but the mechanism can be initiated and controlled by the driver irrespectively of tiltback and its energy costs are independent of the neutral target pedal angle, i.e. of the tiltback.

I mean if you lift a weight what takes more energy, letting your arm hang straight down, or holding your arm at an angle? I think the detail you're missing (I assure you're not alone) is just that the pedals are not mounted directly at the wheel axle - the pedal _arms_ are mounted to the axle.

It doesn't matter if you stand on your toes or on your heels, it makes no difference for how much power is needed to 'lift' your weight. Because the hinges that make it possible to fold up the pedals, all your weight is always on those hinges! To rotate the shell, those hinges must go higher from the ground (lifted).

For example on a hoverboard if you hit a bump, the initial effect will be that it _rolls_ forward, because you're standing on top of the wheel axle. Pretty unstable! However on an EUC it's the opposite. The initial effect of the shock is actually that pedals _swing_ forward (shell rolls backward). Superior construction!

[Mono]

Sorry, I still don't see the relevance of tilt angle of the pedals for the energy balance of the vehicle. The pedals can be anywhere, below the axis, above the axis, it just doesn't matter. And whatever the inclination angle of the wheel shell is, it doesn't matter as well. Only, the ground contact point is always kept under the CoG of wheel+body, and to support the body at least some part of the pedals must be under the CoG of the body. That only means, the pedals cannot be entirely sideways, some part of them must more or less overlap vertically with the axle to support the weight. If there is no body on the wheel, the relation between CoG and contact point already determines fully the inclination angle of the wheel and there is no free parameter left. If there is a body, the additional free parameter is the angle between body and wheel. 

Here is a simple experiment: I turn the wheel off = zero power. I grab something fixed and stable with both hands. Now, I can mount and keep the wheel under me with essentially no effort just careful, subtle balancing (careful: it's not super easy and the wheel might just roll away under you and hit and break something in the first attempt). Now I can change the tilt angle of the pedals and this changes nothing but the angle, no additional effort, just need to keep careful balance.

Here are two related questions:

• if we change the horizontal pedal alignment in the app, does that have an effect on the energy consumption of the wheel?
• do you think that tiltback is more than just (re-)setting the horizontal pedal alignment to a different value?

[Mono]

3 hours ago, nomad said:

It doesn't matter if you stand on your toes or on your heels, it makes no difference for how much power is needed to 'lift' your weight. Because the hinges that make it possible to fold up the pedals, all your weight is always on those hinges! To rotate the shell, those hinges must go higher from the ground (lifted).

Where a specific point of the system moves to is not that important. If the hinges were constructed differently (say they are an elongated axis), some part of them would move down, some part would move up. Your point is that weight must be lifted. For this, the CoG of the rider must go up.^1 While their CoG is in principle entirely in the control of the driver, let's assume the driver doesn't change the posture at all (apart from the feet angle, which is forced). Then, the CoG will even move down, not up, at least on my wheels: 

If I tilt the pedal back on my wheels, the backend of the pedal moves down, not up. The backend of the pedal is what the heel of the rider is placed on. If the rider doesn't change their posture, under tiltback their heel and hence their CoG goes down, not up. The effect is small so that it is hardly noticeable though and I don't see that it is relevant. Meanwhile the driver has the choice to either lift the forefeet or fall behind the wheel on the ground.

^1 As a side note, the CoG of the wheel itself also goes down when tilting the shell from an upright position, because the CoG is above the axle.

[nomad]

You're right there is a difference between where the weight is placed on the pedals of course. But keep in mind the front of the pedals also have a significantly more vertical trajectory, the back of the pedals move more horizontally than down during tiltback! More vertical movement needs more power. I took the pedal hinges as an example, as they show that the pedals are not only rotated by themselves but also elevated at an angle as a whole unit.

Yes my point was that 'lifting' is involved when tiltback is increasing the angle. Because you are not controlling tiltback, tilback controls you! That means it's impossible to fully predict the movement. In essence the extra resistance for the motor will be mainly to push up the front of the pedals. In order to get tiltback, there must be acceleration before leading to triggering it. So you are already applying pressure in front before it activates.. Your weight will be even more shifted toward the front of the pedals when it kicks up the angle.

That's why your neutral angle probably doesn't matter so much when it starts rotating up under your feet. Basically tiltback will do an action and the automatic reaction from you is applying more pressure in front asking for even more acceleration than before. If successful the wheel speeds up while you lean back, so you can be slowed down safely without overleaning. I can't see this work without using extra power.

[Mono]

24 minutes ago, nomad said:

Basically tiltback will do an action and the automatic reaction from you is applying more pressure in front asking for even more acceleration than before. If successful the wheel speeds up while you lean back, so you can be slowed down safely without overleaning. I can't see this work without using extra power.

I would say the automatic reaction to tiltback is to release pressure on the forefoot, i.e. moving the forefoot up, but that is probably just a different view point. Otherwise we are in full agreement. In order to slow down, the wheel must get in front of the driver which needs some additional energy for speeding up (not a lot energy though as it doesn't need to push the driver, only the wheel). This slowing down process is what tiltback incentivises the driver to let happen. However to say tiltback needs energy instead of saying initiating a slow down needs energy seems to be a little misleading then.

[Marty Backe]

Thanks for your detailed description. It was a very interesting read. Glad you will recover 

This reaffirms my riding style - keep away from max speed. I have tilt-back turned off on all of my Gotway wheels, but I always stay 15-20% below max speed and reduce my maximum speed when battery levels starts getting in the 30% range.

[nomad]

13 hours ago, Mono said:

I would say the automatic reaction to tiltback is to release pressure on the forefoot, i.e. moving the forefoot up, but that is probably just a different view point. Otherwise we are in full agreement. In order to slow down, the wheel must get in front of the driver which needs some additional energy for speeding up (not a lot energy though as it doesn't need to push the driver, only the wheel). This slowing down process is what tiltback incentivises the driver to let happen. However to say tiltback needs energy instead of saying initiating a slow down needs energy seems to be a little misleading then.

I'm no EUC engineer but I think what happens, and what is probably the safest method, is that it just changes the neutral angle of the gyro, so there's not any preset tilting movement. It should react proportionally to how hard you attack it. Unless you react at the speed of light or can predict the exact future movement, the tiltback will try to push the pedals up. As the back of the pedals don't go down so much and actually moves more horizontally, there's definitely a significant lifting movement at the front.

It starts accelerating as the neutral tilt angle is suddenly switched to a different angle. It will keep accelerating until the new set angle is reached. But as you are standing on the pedals there is resistance. Because you resist the backward roll of the stator/shell/pedals, it results in increased speed to the ground. This goes on until either the new angle is reached or a higher rotation speed is reached. If pedals are pushed back fast that actually helps the motor accelerate a bit. If speed increases the angle can be offset even steeper up the tiltback curve, you'll be chasing a moving target at this point.

When rotating the shell the pedals do not only rotate, but they also move forward, it swings your feet forward and shifts the center of gravity. You always reach tiltback activation speed because you accelerate into it. This means you never go into tiltback with a neutral stance on the pedals, you must have a forward pressure, unless you're going downhill and gravity does it for you...

[Mono]

 @nomad that seem all quite accurate, but it does not suggest that there is additional energy consumption, additional to what would be needed to slow down the wheel anyways.

Re CoG: it turns out that the overall CoG of the wheel and (independently) the CoG of the driver (without a change of posture) both go down when the pedals tilt back. I don't see how it matters though as the driver is in full control to move the CoG down or up. I do think indeed it is a very useful reflex to bend knees in critical situations, thereby for a moment releasing weight off the wheel and (as a necessary consequence) moving the CoG down. It gives the wheel a small but possibly decisive moment to recover from an overload. It also doesn't matter whether the driver does knee bents while driving. Unless the knee bents lead to speed changes, the overall energy balance of the wheel remains the same, AFAICS. Not the energy balance of the driver though 

I assume we both agree that the wheel has only very limited ways to do something? It can only either apply more torque or less torque (between frame/shell and the moving part of the wheel) and thereby changing its rotation speed as a consequence, right?

That means that the notion of "the tiltback will try to push the pedals up" is somewhat misleading. It is the driver pushing the pedals up in order to slow down the wheel as a reaction to the wheel increasing its speed under the current pedal angle, under which speed was constant before.

Now simply from an energy balance perspective, I don't see a way how the horizontal pedal adjustment angle can change the energy balance. The additional energy must be converted either in kinetic energy or in heat and its not clear to me how this is happening.

Maybe it would help if I understood where this idea that tiltback consumes energy originated from, as I assume the weight lifting point is an explanation given only after the hypothesis was already formed.

[Slaughthammer]

2 hours ago, Mono said:

Maybe it would help if I understood where this idea that tiltback consumes energy originated from, as I assume the weight lifting point is an explanation given only after the hypothesis was already formed.

maybe this video might clear things up a bit:

IMHO, if you have such a small torque reserve, that you need to fear a cutout because the wheel tries to enforce a tiltback, you shouldn't be riding that fast in the first place, e.g. your tiltback speed is set to high.

[Mono]

7 minutes ago, Slaughthammer said:

maybe this video might clear things up a bit

Nice crash recording! I don't see though how it can answer the question how tilt back works, or that tilt back could be a reason for a reduced torque reserve.

[nomad]

Let's say a test was done with a person having 0.5 seconds [reaction time] to pedal force feedback. Steady acceleration from standstill right up to preferred speed (unknown by rider but measured exactly 27 km/h in every test). No tiltback felt during acceleration, because of constant pressure and steadily reduced torque over the speed range of the motor. At exactly 27 km/h (still unknown by the rider) the following happens:

Case 1.
No tiltback:

At 27 km/h.. preferred speed is reached. Immediately [ease off pressure] from front of pedals, wheel continues to cruise along at 28 km/h...

Case 2.
No tiltback:

At 27 km/h.. immediately [apply harder pressure] to front of pedals to accelerate up to 30 km/h. One second later the wheel has folded.

Case 3.
Tiltback normal curve activated at 21 km/h, agressive curve at 23 km/h, extreme at 25 km/h, final extra forceful curve activated at 27 km/h:

At 27 km/h.. unpredictably but only momentarily feel [pressure] coming up from the pedals (as if you would [apply harder pressure] to front of pedals). One second later the wheel has folded.

If a test turned out something like this I don't think I'd question the results, I guess it would just seem plausible to me.

[charlesrg]

I just had a similar issue on my InMotion v8 and I had never adjusted the tilt, I just increased the max speed tom 19mph and today the thing just cuttoff completely. Feel very similar to what the OP described. Sudden loss of torque and you fall forward. However my reflexes instead of trying to run my legs braced the wheel and I felt with the v8 almost between my legs.

I'm looking for a way to retrieve logs and find why it did that.

[contactsports]

Hi all, I purchased a v5f+ a few months ago after seeing one for the first time.  I've put about 250 miles or 400km on it to date.  A few days ago I was out for one of my rides, cruising around listening to music.  I drive pretty aggressive, having fun, mostly riding the edge of cutoff or cutoff.  I was close to wrapping up, did a 180 and an aggressive acceleration; I think the thing folded, and I hit the deck.  Had no chance to run off at that point; hands took most of the impact, but so did my chin, 15 stitches and a slightly displaced left front tooth.  Never experienced this before.  Took it out the next day and continue to ride it, obviously a little more cautious, but curious if this was solely my issue, a bug or combination.  It still had 3 or 4 bars of power, so I don't think it was power related. I don't recall the exact horizontal adjustment, but it went to -0.9 when I did a reset.  I've seen -3.0 recommendations, but I'm not sure if any setting would have helped.  I'm thinking I was just too aggressive on the lean and when the tiltback kicked in, I wasn't able to pull back fast enough, but I'm pretty sure I've done this many times before.

On a separate note, is there any security built into the app to prevent settings modifications without authorization?  It seems anyone with the app can modify your settings, assuming they are in bluetooth range.  What would happen if your cruising at 16mph and someone slides the speed bar to 1mph?

Thanks.

[Marty Backe]

17 hours ago, contactsports said:

Hi all, I purchased a v5f+ a few months ago after seeing one for the first time.  I've put about 250 miles or 400km on it to date.  A few days ago I was out for one of my rides, cruising around listening to music.  I drive pretty aggressive, having fun, mostly riding the edge of cutoff or cutoff.  I was close to wrapping up, did a 180 and an aggressive acceleration; I think the thing folded, and I hit the deck.  Had no chance to run off at that point; hands took most of the impact, but so did my chin, 15 stitches and a slightly displaced left front tooth.  Never experienced this before.  Took it out the next day and continue to ride it, obviously a little more cautious, but curious if this was solely my issue, a bug or combination.  It still had 3 or 4 bars of power, so I don't think it was power related. I don't recall the exact horizontal adjustment, but it went to -0.9 when I did a reset.  I've seen -3.0 recommendations, but I'm not sure if any setting would have helped.  I'm thinking I was just too aggressive on the lean and when the tiltback kicked in, I wasn't able to pull back fast enough, but I'm pretty sure I've done this many times before.

On a separate note, is there any security built into the app to prevent settings modifications without authorization?  It seems anyone with the app can modify your settings, assuming they are in bluetooth range.  What would happen if your cruising at 16mph and someone slides the speed bar to 1mph?

Thanks.

Ouch! You learned the importance of safety gear the really hard way. Sorry to hear of your injuries 

Personally, I don't even perform aggressive accelerations on my most powerful wheels. The longer you ride the more you realize the tremendous load that is put on a wheel when you step on the gas hard. IMO you increase the risk of a cutout and I just don't want to hit the ground any more. So I play the odds and am instead a mellow accelerator unless absolutely necessary (avoiding a car, etc.).

I suspect this cautious attitude forms as you ride more and have more falls along the way. When you are starting, like yourself, you haven't attended the school of hard knocks long enough.

The v5f+ is not a wheel that I would ever perform hard accelerations. From your description, you simply demanded more from the wheel than it's capable of delivering. I suspect that there's nothing wrong with it.

Regarding remote connection to the wheel as you ride, that's a concern that shouldn't be. The odds of you coming across someone who would want to do harm to you, that would have the app and know how to use it, and be able to connect rapidly, etc. is zero. On my Gotway wheels, the wheel has to be non-moving for any mode changes to take affect. I don't know about the v5f+. You could do a simple (safe) test. Ride at 5-mph and then change to 3-mph and see what happens. But really, don't worry about this until your neighborhood contains thousands of EUC riders.

[Smoother]

Plus 1 for what @Marty Backe said.  Once you have discovered all the ways an EUC can throw you on your face, you will calm down.  Or...hopefully before that.  Read our mistakes and learn from them as if they were your own.

18 hours ago, contactsports said:

I drive pretty aggressive, having fun, mostly riding the edge of cutoff or cutoff.  I was close to wrapping up, did a 180 and an aggressive acceleration;

You might as well have said " I push too hard all the time and finally it came back to bite me". Kudos for sharing, now read back what you wrote and see how it really just say "crash, crash, crash". And Yeah a V5f+ is no wheel for aggressive riding.  But please don't read that as " get a more powerful wheel and everything will be ok".  If you rag a powerful wheel, stitches and a loose tooth will be "the good old days"

Oh yeah, @contactsports welcome to the club.  Was your "handle" a premonition? 

One more thing:  "It still had 3 or 4 bars of power".  Is that out of 10?  If so that's the danger zone.  Read up about voltage sag, to understand why.  A lithium battery is not like a gasoline fuel tank, you can't put the pedal to the metal until the last drop.  What's left in your batteery is a power reserve that can be temporarily sucked dry (voltage sag) and dump you on your face.  Get back up and the batteery still reads what it read before the fall, but it doesn't show the voltage sag that shut down power to the wheel for a fraction of a second or so.

[Marty Backe]

2 minutes ago, Smoother said:

Plus 1 for what @Marty Backe said.  Once you have discovered all the ways an EUC can throw you on your face, you will calm down.  Or...hopefully before that.  Read our mistakes and learn from them as if they were your own.

You might as well have said " I push too hard all the time and finally it came back to bite me". Kudos for sharing, now read back what you wrote and see how it really just say "crash, crash, crash". And Yeah a V5f+ is no wheel for aggressive riding.  But please don't read that as " get a more powerful wheel and everything will be ok".  If you rag a powerful wheel, stitches and a loose tooth will be "the good old days"

Oh yeah, @contactsports welcome to the club.  Was your "handle" a premonition? 

[contactsports]

28 minutes ago, Marty Backe said:

Ouch! You learned the importance of safety gear the really hard way. Sorry to hear of your injuries 

Personally, I don't even perform aggressive accelerations on my most powerful wheels. The longer you ride the more you realize the tremendous load that is put on a wheel when you step on the gas hard. IMO you increase the risk of a cutout and I just don't want to hit the ground any more. So I play the odds and am instead a mellow accelerator unless absolutely necessary (avoiding a car, etc.).

I suspect this cautious attitude forms as you ride more and have more falls along the way. When you are starting, like yourself, you haven't attended the school of hard knocks long enough.

The v5f+ is not a wheel that I would ever perform hard accelerations. From your description, you simply demanded more from the wheel than it's capable of delivering. I suspect that there's nothing wrong with it.

Regarding remote connection to the wheel as you ride, that's a concern that shouldn't be. The odds of you coming across someone who would want to do harm to you, that would have the app and know how to use it, and be able to connect rapidly, etc. is zero. On my Gotway wheels, the wheel has to be non-moving for any mode changes to take affect. I don't know about the v5f+. You could do a simple (safe) test. Ride at 5-mph and then change to 3-mph and see what happens. But really, don't worry about this until your neighborhood contains thousands of EUC riders.

Appreciate the feedback.

I don't plan to change my riding style much, except for less aggressive accelerations based on feedback and recent experience.  To each their own, but I probably wouldn't be riding this much if it was straight, narrow and lower speeds.  I don't use this for commuting, rather cruising around and having fun.

Would a hard acceleration like that cause a massive drain condition, and it would just kick out, meaning no tiltback.  Is that what people refer to as "folding"?  250m/450km may not seem like a lot, but I've driven this thing pretty aggressively and never had this happen.  Is the battery wearing down slightly vs when it was brand new and it can't handle this short term drain from a burst acceleration?  I'm not saying my riding style wasn't the main factor, just trying to figure out what would cause this.  It felt like the thing just stopped.

[contactsports]

27 minutes ago, Smoother said:

One more thing:  "It still had 3 or 4 bars of power".  Is that out of 10?  If so that's the danger zone.  Read up about voltage sag, to understand why.  A lithium battery is not like a gasoline fuel tank, you can't put the pedal to the metal until the last drop.  What's left in your batteery is a power reserve that can be temporarily sucked dry (voltage sag) and dump you on your face.  Get back up and the batteery still reads what it read before the fall, but it doesn't show the voltage sag that shut down power to the wheel for a fraction of a second or so.

 

The V5F+, at least mine, has 5 bars.  Mine is pretty much always fully charged before I go out, and I don't ride that long.  I would say it was around 65-75% charged at the time.

[Smoother]

12 minutes ago, contactsports said:

Would a hard acceleration like that cause a massive drain condition, and it would just kick out, meaning no tiltback.  Is that what people refer to as "folding"?  250m/450km may not seem like a lot, but I've driven this thing pretty aggressively and never had this happen

Yes.  Especially if below 60% charge.

 

12 minutes ago, contactsports said:

Is the battery wearing down slightly vs when it was brand new and it can't handle this short term drain from a burst acceleration?

No.  Unless you've been abusing the battery (overcharge, under charge)

 

12 minutes ago, contactsports said:

I'm not saying my riding style wasn't the main factor, just trying to figure out what would cause this.  It felt like the thing just stopped

What's to figure out?  it's been explained already;  Small battery, weaker motor, low battery charge, aggressive riding, hard acceleration.  If you don't believe any of this, keep doing what you're doing and the results will be the same.  You have to understand and respect the unique characteristics of electric unicycles if you want to remain upright.  You can do that at the school of hard knocks, or here at the school of other people's hard knock ( to which you have nobly contributed )