Jump to content

Recommended Posts

1 hour ago, Bob Eisenman said:

Any thoughts on @Hsiang 's recent Z10 crash?

 

 

@Hsiang mentioned in the video that this happened when he accelerated out of the turn. Unfortionately there is not too much detail to be seen in the video. He becomes ?over/im?balanced foward , then the z10 catches up again causing him to totally loose balance and crash...

Seems while he gets his imbalance forward he reacts by bending his knees (going down) so he cannot take the force of the wheel accelerating again?

(?Some?) wheels when not properly calibrated tend to tip forward while taking a bend. Maybe this in combination with leaning foward to accelerate out of the bend could have caused the first imbalance?

Maybe this was a "normal" overlean asking too much acceleration going out of the turn?

Maybe there was some small incline from an unevenness in the road/some pebble/branch which added additional burden/way on top of the acceleration?

Maybe some firmware/battery issue - i'm not really into Z10 probs but there was something mentioned of one of the two battery packs disconnecting? Don't know if this could have been a cause in this situation?

I experienced myself till now two cases were accelerating over some (by me unseen) "hole"/unevenness i first got an imbalance forward (by going slightly down this uneven part), at the following small incline the wheel stayed a bit behind and i saw the road coming nearer and nearer preparing mentally for my first faceplant. Then in the next instant the wheel zipped forward and caught up with me again... Fortionately this happened going straight and not while turning 😎

Ps.: Seems not logic to get the imbalance by going down into this uneveness - should be happening when the wheel goes up again. There it has a longer way to go (so more acceleration to stay under the driver) and additionally an incline to overcome (which could cause a temporary overlean)...

Edited by Chriull
  • Like 1
  • Upvote 1
Link to comment
Share on other sites

1 hour ago, Bob Eisenman said:

Any thoughts on @Hsiang 's recent Z10 crash?

 

He says it happened when he started to accelerate. I think, we see the wheel nose dipping, then he can almost save it while the wheel accelerates and gets back under his body and then he loses completely control.

The interpretation crucially hinges on the questions how fast he was going and how strongly he tried to accelerate. I also wouldn't exclude that it was the same mechanism as this fall, stuttering lose of grip while accelerating in a curve (consider that there were isolated leafs laying around all over the road surface):

 

Edited by Mono
  • Like 2
Link to comment
Share on other sites

25 minutes ago, winterwheel said:

It looks to me like the Z10 can have a hiccup (with potentially severe consequences) if even a minor traction anomaly occurs at speed, and this is magnified when turning.

In my opinion the Z10 is capable of handling perfectly at high speeds with aggressive handling and uneven terrain without problems. I posted here a video a few days ago riding the Z10 at top speed, hitting bumps and rough urban obstacles with the usual wobbles but no issue at all. I find it impossible to overpower the tilt back and feel perfectly safe at top speed all the time. The riding style might need some anticipation to certain temperamental Z reactions but practice always helps. Feel way unsafer on my MSX going top speed, even though it is like on rails, not receiving any 80% power warnings reaching 56km/h with no tilt back is unnerving, you never know the absolute limit of the wheel.

  • Like 1
Link to comment
Share on other sites

1 minute ago, Damarafaka said:

In my opinion the Z10 is capable of handling perfectly at high speeds with aggressive handling and uneven terrain without problems. I posted here a video a few days ago riding the Z10 at top speed, hitting bumps and rough urban obstacles with the usual wobbles but no issue at all. I find it impossible to overpower the tilt back and feel perfectly safe at top speed all the time. The riding style might need some anticipation to certain temperamental Z reactions but practice always helps. Feel way unsafer on my MSX going top speed, even though it is like on rails, not receiving any 80% power warnings reaching 56km/h with no tilt back is unnerving, you never know the absolute limit of the wheel.

For sure it can handle big speeds and rough terrain or they wouldn't be selling it.

But the videos appear to show that every once in a (perhaps very long, statistically speaking) while, things go south. In the third video it is clearly an issue with hitting a drain while turning. In the second, there is speed and turning involved (although we are too  far away to see if there is any contributing surface issue) and in the first, something happens with the wheel exactly at the point that it hits the part of the road that is in shadow. Unless someone comes up with something more concrete in the way of what is happening, that's how I'm going to interpret what I'm seeing.

Link to comment
Share on other sites

4 minutes ago, winterwheel said:

For sure it can handle big speeds and rough terrain or they wouldn't be selling it.

But the videos appear to show that every once in a (perhaps very long, statistically speaking) while, things go south. In the third video it is clearly an issue with hitting a drain while turning. In the second, there is speed and turning involved (although we are too  far away to see if there is any contributing surface issue) and in the first, something happens with the wheel exactly at the point that it hits the part of the road that is in shadow. Unless someone comes up with something more concrete in the way of what is happening, that's how I'm going to interpret what I'm seeing.

You're right, every now and then things go south and ninebot knows quite a lot about this, and they've always been accepted until now as the gold standard in quality and safety. I think the problem is more about the new speeds the current generation euc's reach and that it takes time and practice to adapt. Speaking about the Z10 you have to add a whole new re-learning curve to the equation. More than hardware or software failures I think it is usually more a mix of bad luck, not seeing something coming, not knowing the wheels reactions/cutoffs at these high speeds good enough, bad foot placement combined with slipping, getting nervous or just being tense because of insecurity, can also trigger a fall. Of course we want to be aware of the causes of these accidents to be able to avoid them, especially when a new model comes out and the always possible technical failures associated but unfortunately with more wheels every day...more incidents, but sometimes being too obsessed with nasty falls and not knowing the cause just puts unnecessary fear in you.

  • Upvote 2
Link to comment
Share on other sites

Here's my take on videos I see of people eating it.

1. In chooch's video, I think the reason why he ate it was because the torque applied to the wheel when he was turning and leaning forward. Chooch is pretty light and plus being in mid turn and forward on pedals to accelerate there isn't much weight being put on the center of gravity for the tire. So its possible the wheel simply burned out. I am thinking ninebot has a safety built in that causes wheels with momentary sudden accelerations to go into a corrective adjustment type of deal that sorta limits the torque on the wheel. It's a tough formula to crack.

Imagine taking some air on a wheel and while mid flight your feet might tip forward and the wheel will simply overaccelerate and trigger a cutoff. You would think that it would make sense to limit acceleration or disable it mid flight but then what happens if you mistakenly apply this characteristic when a person goes over a small bump and immediately has the sudden acceleration but then finds themselves on sturdy ground again. You might begin corrective actions which would put the rider in an off balance situation.

2. In the video where the group is riding and the guy overtakes on the left and face plants, I looks like he hit a small bump and the wheel immediately just gave up balancing. I'm wondering if the Gyroscopes are reporting sporadic data in situations with vibration and the controler is "compensating" for these motions even though they theoretically should be avoiding them. The wheel is smart enough to shut off in the event of a tipover. I'm wondering if too many vibrations to the gyro or sudden jolts is causing the Nine to pick up too many "tipped over" readings that it triggers a shutoff. Maybe the shut off trigger is occuring and immediately the right up trigger is following so people get that "whoa" sensation and ultimately eat it.

On my Z, I've had the unit alarm while doing tight turns. Not enough to scrape a pedal, but enough to do a sharp u-turn (unintentional as part of my learning to ride) but I'm going no more than 1MPH and it's alarming at me like I'm tipping over.

 

The darn wheel is so smart that it's "over analyzing" the situation to put it in layman's terms.

 

Trying to put a picture into words, Imagine a glass ball with a drop of mercury in it. As you roll the ball, the mercury will try to find it's way to the bottom center. Take that ball and shake it up and down once really fast, if you had a camera running in slow mo, you could see the mercury at the top of the ball for a moment. If you were to snap a picture and show it to someone and ask them to right the picture to where they think it should be, they would probably flip it around so the mercury was on the button. That's the best I can describe it. The Z might think it's upside down for a second and it cuts out?

Edited by darkflame808
  • Upvote 1
Link to comment
Share on other sites

For me it's pretty convincing that hitting that obstacle while turning caused the problem. I have no idea how much of this particular incident is the responsibility of the wheel and how much goes to the rider.

Edited by winterwheel
  • Like 1
  • Upvote 1
Link to comment
Share on other sites

7 hours ago, winterwheel said:

For me it's pretty convincing that hitting that obstacle while turning caused the problem. I have no idea how much of this particular incident is the responsibility of the wheel and how much goes to the rider.

Looks like that the tire pressure was too high, too bouncy. I remember that this happens before he lowered the pressure.

Link to comment
Share on other sites

  • 2 weeks later...

My ninebot one z10 make some noises if I drive slowly. If I am faster, than I can't hear anything. Driving noises. I lay it on the ground and wake it. Every 180° turn of the wheel it has a little play. Is this a simular Problem like Gotway before? The tube shakes left right a little bit wenn I drive, not like Gotway forward backward. Do anyone know of this Problem at ninebot one z10? I only drove 20km when I recognised.

Link to comment
Share on other sites

4 hours ago, BaronvonHansi said:

My ninebot one z10 make some noises if I drive slowly. If I am faster, than I can't hear anything. Driving noises. I lay it on the ground and wake it. Every 180° turn of the wheel it has a little play. Is this a simular Problem like Gotway before? The tube shakes left right a little bit wenn I drive, not like Gotway forward backward. Do anyone know of this Problem at ninebot one z10? I only drove 20km when I recognised.

No idea about these Ninebots, but form a mechanical point of view talking like that I just think bearings, shims and anything mechanical that can create a play like that.

I would not ride a single more meter if I where you until someone who do know about them Z Ninebots can confirm and help you locate the problem, kind of a standard safety measure imho, at least til you know and can take a new stance again.

With cars to at times you can hear it slowly, at some speeds it can go away or seemingly go away at least, but  does not mean it's advisable to keep going cause you cannot hear it at certain frequencies, min locate the problem is my advice at least. With the Gotway shims we know what it is and perhaps not likely to create a big accident right away even if feeling some play, someone who own and/or know the model will come help you out with ideas soon no doubt.

Edited by Electroman
Link to comment
Share on other sites

ok yaay, i figured out how to calibrate my pedals to level. when it asks to lock the wheel and then goes limp, put the front up a full bubble on ur level and then press ok. took me three tries but it finally works and i turned it off and on 3 times and it went back to dead level. 

and i was wrong or my floor isn’t level, mine does seem to wanna creep forward, like he’s anxious to go. before and after calibration, although when set to level as opposed to frontpedal down, the creep is hardly noticeable.

2018-11-30_08-30-00

 

  • Like 1
Link to comment
Share on other sites

  • 4 weeks later...
6 minutes ago, gigiValliConservigi said:

did anyone know what peak power the Ninebot Z10 has? I've read somewhere in the forum that one guy hit almost 3600w reading the eWheelLog's logs, I wonder if someone know the max wattage value for this wonderful wheel.

I'm not sure if there is an official max wattage spec, or if it can be meaningfully given or tell you much.

One can guess:

Usually, EUC power is limited by what the batteries can do. On a 6p battery/58.8V wheel like the Z10, that would be 6*10A*58.8V = 3528W nominal (nominal = without overheating. 10A is what a typical battery cell can put out as long as it has enough charge.). But such a battery cell can easily do 20A for a short time, so double that. Something around 7000W theoretical peak?

That's easily more than the 1800W nominal of the motor (1800W according to Ninebot. These numbers aren't very exact anyways.). So question is, how quickly will the motor overheat? Usually, a good max motor power number (as much as such a number makes sense) is about double the nominal value, so 3600W. You should be able to do that for a short while, at least.

So 3500W is a good estimate. So the reading you found is realistic.

But the Z seems to limit power in order to protect the electronics, as can be seen on the sluggish downhill braking many people reported. So that may be the real limit.

In the end, I think 3500W (or whatever) is just a number that doesn't mean much. But since you asked:efee47c9c8:

  • Like 1
  • Upvote 2
Link to comment
Share on other sites

@BaronvonHansi

Both my wheel and my friends wheel are louder when they get slower. I have a stripped screw in my mudguard that vibrates as well and makes it even worse at low speeds. I have noticed that my wheel does go back and forth side to side a little bit, at least at lower speeds. Function of the wheel does not seem to be affected. At this point I have 500 miles on my Z10 and have done some heavy off road trails.

Link to comment
Share on other sites

7 hours ago, meepmeepmayer said:

I'm not sure if there is an official max wattage spec, or if it can be meaningfully given or tell you much.

One can guess:

Usually, EUC power is limited by what the batteries can do. On a 6p battery/58.8V wheel like the Z10, that would be 6*10A*58.8V = 3528W nominal (nominal = without overheating. 10A is what a typical battery cell can put out as long as it has enough charge.). But such a battery cell can easily do 20A for a short time, so double that. Something around 7000W theoretical peak?

That's easily more than the 1800W nominal of the motor (1800W according to Ninebot. These numbers aren't very exact anyways.). So question is, how quickly will the motor overheat? Usually, a good max motor power number (as much as such a number makes sense) is about double the nominal value, so 3600W. You should be able to do that for a short while, at least.

So 3500W is a good estimate. So the reading you found is realistic.

But the Z seems to limit power in order to protect the electronics, as can be seen on the sluggish downhill braking many people reported. So that may be the real limit.

In the end, I think 3500W (or whatever) is just a number that doesn't mean much. But since you asked:efee47c9c8:

Thank you so much, that's the answer that I'm looking for. 

 

  • Upvote 1
Link to comment
Share on other sites

54 minutes ago, palachzzz said:
5 hours ago, winterwheel said:

Are these withe the stock tire?

Yes.

And.. unlocked 50km/h )

Awesome. I had decided not to buy a Z10 because I wasn't confident that weird tire would do well in snow. Looks like it's back in the game.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...