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Marty Backe

My Z10 Triumphs, Tribulations, and Failures

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7 hours ago, mrelwood said:

It’s the Msuper X. Looks almost like the MSX rider is just chilling while Marty is all out of breath and working his way through the tough spots! :roflmao: Must be a visual perspective thing though...

I tend to me a more 'tense' rider in this conditions whereas @Jrkline "Wheel Whisperer" is a very loose rider. His looseness might contribute to the face that he has more "land on your ass" falls from the wheel than I do :laughbounce2:  There's also the distinct advantage with the MSX having a tire that's almost 2-inches larger in diameter and pedals that float over all obstacles. And the Z10 is a heavier wheel.

If you actually focus on Jeff in this video, you will see that he's working quite a bit to stay upright. But he's an excellent rider, no doubt about it :thumbup:

Edited by Marty Backe
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44 minutes ago, Arbolest said:

 

This is  interesting and brings up a valid point. But I think that what may be behind the weird braking issue is actually a lot simpler than many of us are assuming (Please, anyone with greater electrical knowledge feel free to strike this idea down, but do give a thorough explanation as to why ;)).

While it is true that a forward spinning motor like the type used in EUCs will generate a back-EMF as it rotates, which can be collected/stored for use later (regenerative braking), I feel like not enough attention is payed to the fact that this is NOT the only way that EUC's (and even most other electrically driven motors) slow themselves down. The simplest form of braking with these (and most types of) electric motors is simply to have the speed controller that's governing the motor's rotation run it backwards. I mean, instead of letting the siphoning off of the back-EMF cause the braking, the device just applies current in a cycle that opposes the motion of rotation. While no-where near as efficient in terms of power-savings (it saves zero power...In fact it uses even more :efee612b4b:), this is a WAY easier to implement.

I find it easiest to think of this form of braking as the controller pushing something (a wheel) to a stop, and I see regenerative braking more as letting the motor itself pull you to a stop...

I feel like Ninebot must have just done something like this for their braking routines instead of following along with the other EUC makers (no idea why though...). It may even help to explain why it feels so weak when trying to brake going downhill! Hear me out on this one:

First, think about this from the wheel's perspective if you can. Dealing with inclines and declines is quite a bit different than riding around on a nice flat road somewhere. When you're riding up or down on a slope, the wheel also has to deal with your weight, which is a big deal for these machines because they're essentially having to either work with or fight against a constant acceleration. That means that just staying still means putting out a lot of power if the slope is even slightly steep, much less actually accelerating on it!

In addition to this, and this is the kicker, the wheel has to deal with MOMENTUM. When going uphill, the wheel is applying power in the same direction as you are moving. It's working WITH your momentum. But downhill? Especially riding STEEPLY downhill? Whew, that must be torture for the poor little things... They have to work AGAINST your momentum. They have to:

1) Use power to keep you upright

2) Use power to hold up your weight (fighting an acceleration)

3) Use power to DIRECTLY OPPOSE YOUR DOWNHILL MOMENTUM

That last one, which anyone who has ridden one of their e-horses (I love that term, @Toshio Uemura) downhill at speed would know with startling clarity, is an incredible feat. The amount of kinetic energy these wheels are able to overcome can be truly astounding sometimes... Just imagine how much force that you (as a human being) would need to apply in order to try and slow down a fully grown adult going 15-20 miles per hour downhill within a reasonable distance...

In case that didn't make sense, try this mental image on for size: Consider that riding on an incline is like constantly riding your wheel while aggressively leaning forward/backward on a flat road. If you're riding up or down a hill with a 20 degree slope, that's effectively like trying to accelerate/brake by leaning forward or backward by 20 degrees on a flat road. Now imagine adding in the stress of breaking on top of that, and you'll start to see how much power you're actually asking from the wheel. 

If the Z10 is only braking directly and trying to push you to a stop, instead of boosting its effectiveness with regenerative braking and effectively pulling at the same time... It's going to have some problems, especially when compared to wheels that both push and pull simultaneously... 

If you think about the evidence of the Z10's handling on downhill braking. It feels as if it doesn't provide as much power/torque, BUT IT DOES. It's just that it's trying to fight your momentum with one hand (and leg) tied behind its back! This would make it feel MUCH weaker to us when comparing it to any other wheel because we're used to that great synergy (and amazing stopping power) that can be achieved if regenerative braking is implemented properly! The wheel is still giving us just as much power as it would in any other situation. The problem is that that's ALL it's giving us!

Sound's a bit silly, right? Why would Ninebot ever do something like this?!?! I think we need to ask... because if this is actually the case, then there's some work that needs to be done, and I do mean ASAP! 

Now see, this is intensely interesting to me! As soon as I read this, I immediately saw a problem with the fact that only ONE battery regained 20% of its capacity...  This shows that the system actually IS regenerating some power and storing it but... That means that the system as a whole only regenerated HALF as much capacity as the other equivalent wheel!?!? If it was really dumping ALL of the regenerative power (or as much as it didn't need to use elsewhere...) back into a single battery pack that only had half the total capacity of the system, then it should have jumped by 40%, right? 

What I mean numerically is simple (going to use nice round numbers for this):

If our two test wheels each have 1000wh capacities to start off with (a single 1000wh battery for the Tesla and 2 individual 500wh batteries for the Z10) , and both were run down to 600wh remaining by the time they made it to the top of the mountain (600wh for the Tesla and 300wh for each pack in the Z10), then everything is good and even. BUT, on the downhill run, if the Tesla regenerates back up to, say, 800wh remaining (20% capacity change) for 200wh of total regen, and the Z10 has its battery packs reporting at 300wh remaining (0% capacity change) and 400wh remaining (20% capacity change) for 100wh of total regen, then something is very wrong with that! 

First, it makes no sense to me why Ninebot would implement regenerative breaking, but only for half the system... And then what the heck is it doing with the rest of the power it's getting back from the motor?!?!

THIS CAN'T BE THE WHOLE STORY HERE!

I don't remember how the Z10 battery packs are connected together. If they are directly wired together then I agree with you. However, if they both plug into the control board, then I see no reason to assume that they would auto-balance. Especially if the board has some way of monitoring battery temperature or some other parameters that can help it make an informed decision as to which battery to pull the most current from at any given time. For example, let's say that one battery tends to heat up faster than the other... It would be more efficient (and safer) to draw a larger percentage of the needed current from the battery that tends to stay cooler.

*sigh* I almost would have been happier to hear that the system wasn't using any of the regenerative power at all, because then it would still be a straightforward, plain old mystery. Either that or that all of the power had been dumped back into the single pack which would have just indicated a balancing issue... But now I'm just confused, because those results mean that it's only regenerating at half the efficiency of the other wheels! What's going on here?! :huh:

A lot of good stuff here, and an interesting read.

The only bit I'll add is that I agree with your observation that it's odd that the one battery that got the recharge only got about half the amount I would have expected.

The Z10 seems about as efficient as other wheels. When we climbed the 4600-feet, the Tesla and I were within a few percentage points all the way up the mountain. Yet I only got effectively half the recharge amount on the return trip that the Tesla got. Odd.

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5 hours ago, that0n3guy said:

If your only charging 1 battery durring breaking I would assume the system can handle only half the amps...  This would account for weaker breaking.

No, as said...it doesn’t matter where the energy which is left over from regenerating goes...you can blow it in the air, by heat, you can pump it in the battery, you can pump half in the air, and half in the battery...but this all shouldnt change the braking behaviour, as just that what  is „left over“ goes into batterys or air or capacitors...there is only a very, very small part of the energy which is recuperated, that is needed at all for breaking and directly consumed by motor. 

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3 hours ago, Marty Backe said:

Z10 seems about as efficient as other wheels. When we climbed the 4600-feet, the Tesla and I were within a few percentage points all the way up the mountain. Yet I only got effectively half the recharge amount on the return trip that the Tesla got. Odd.

Reading this I am just wandering in general, if you would drive by car with your fully charged wheel to the top of a mountain and make a few steep high speed descents over a few hours could that overload and damage or even explode your batteries? Or are they protected from overloading in such a situation? Is this something to be careful about? Because in some of my mountain rides the parking lot is up higher then where the trail begins, so you first have to go back a few minutes downhill if you don’t want to park on the road near the trail.

Edited by Toshio Uemura
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I had no ideal what an amazing rider Marty is to jump from 14" wheels to 22" with a very modest adjustment period. I have been riding my KS18L exclusively for a couple hundred+ kilometers and have been ruined. For me going to the 18" inch wheel from the 16" inch wheel was "easy-peasy",. but going the other way .. not so much.

I had not ridden my 9B E+ since I got the KS18L and took it out for a short 3+ km ride to the bank. Oh brother! When  I mounted I could barely stay on and even after I got my balance, riding was very sketchy with the wheel flopping between my legs such that I had grip it with my shins. It was better on the return trip but not solid. I have actually ridden the 9B E+ more miles than the the KS18L, but you wouldn't think it. I am not sure it will work but I will take Toshio's advice and try and ride the 9B E+ after or in between KS18L rides. God forbid I try and ride a 14" or a MTen!

. Marty and other multi-size-wheel riders, I take my hat off to you!

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23 minutes ago, Toshio Uemura said:

讀到這個我只是一般的徘徊,如果你駕車用充滿電的車輪到山頂,並在幾個小時內做一些陡峭的高速下降可能會超載和損壞甚至爆炸電池?或者在這種情況下是否可以防止超載?這是值得注意的嗎?因為在我的一些山地遊樂設施中,停車場比起道路開始時要高,所以如果你不想在停靠在道路附近的道路上停車,你首先要下坡幾分鐘。

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40 minutes ago, Toshio Uemura said:

Reading this I am just wandering in general, if you would drive by car with your fully charged wheel to the top of a mountain and make a few steep high speed descents over a few hours could that overload and damage or even explode your batteries? Or are they protected from overloading in such a situation? Is this something to be careful about? Because in some of my mountain rides the parking lot is up higher then where the trail begins, so you first have to go back a few minutes downhill if you don’t want to park on the road near the trail.

Normally BMS Systems are protected against such overloads...you will for example on a KS/GW/IM first get a warning beeps and later a tiltback trhoeing you off the wheel. So that you have no chance to overload the batterys. I have no clue how 9b handles that on the Z10...especially when i hear regenerative braking goes only into one battery pack!

Historicaly they have not been that great in battery managment, for example the c/e one plus didnt have a balancing for the cells on the BMS.

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4 hours ago, Marty Backe said:

Just checked the battery status this morning. All is fine; both batteries at 100-percent charge. Yea :thumbup:

So I’m assuming the stronger pack began charging the weaker pack through the discharge port and then throughout the night  both packs had a chance to equal out. Not sure why the BMS allowed this to happen in the first place but at least it worked. Congrats!

 

 

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11 minutes ago, Rehab1 said:

I’m assuming the stronger pack began charging the weaker pack through the discharge port and then throughout the night  both packs had a chance to equal out.

When they would be connected like that...there would not have been that difference at all.

Ok, and when this connection would only have been established when plugging in the charger...then it would have been an immediate spark and balancing within the moment of connecting.

So its still a bit mysterious whatsgoing on there!

Edited by US69
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3 hours ago, Toshio Uemura said:

Reading this I am just wandering in general, if you would drive by car with your fully charged wheel to the top of a mountain and make a few steep high speed descents over a few hours could that overload and damage or even explode your batteries? Or are they protected from overloading in such a situation? Is this something to be careful about? Because in some of my mountain rides the parking lot is up higher then where the trail begins, so you first have to go back a few minutes downhill if you don’t want to park on the road near the trail.

You will always experience overload conditions when going downhill on a fully charged wheel. On this very ride, one of the guys was thrown off his Gotway wheel because there's a short downhill section at the very beginning of the 4600-ft climb. He was descending fast and the wheel overcharged and tilted back suddenly, literally throwing him off the the wheel.

On a previous ride the same thing happened to me, except I was anticipating it so I was able to smoothly step off the wheel.

So if you anticipate a somewhat steep downhill section at the beginning of your ride, don't fully charge the wheel.

Edited by Marty Backe
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33 minutes ago, Rehab1 said:

So I’m assuming the stronger pack began charging the weaker pack through the discharge port and then throughout the night  both packs had a chance to equal out. Not sure why the BMS allowed this to happen in the first place but at least it worked. Congrats!

 

 

To be honest, I wouldn't assume anything regarding these Chinese wheels that come with zero meaningful documentation. All I can say with assurance is that both batteries are now fully charged.

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24 minutes ago, Marty Backe said:

...if you anticipate a somewhat steep downhill section at the beginning of your ride, don't fully charge the wheel.

Right, or just ride around a little bit before you go downhill. People who live on a steep slope generally develop some sort of a quick detour habit before they head down their hill.

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Hey @Marty Backe was curious if you get some vibrating on your pebble with the Z10 from amps.... I get it sometimes when I hit a bump but on like 3 or 4 occasions today just going straight, paved rd around 14mph, my pebble is going off, I looked at the graph on the wheellog and it looks like the amp line spiked for no apparent reason???

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11 minutes ago, Marcglider said:

Hey @Marty Backe was curious if you get some vibrating on your pebble with the Z10 from amps.... I get it sometimes when I hit a bump but on like 3 or 4 occasions today just going straight, paved rd around 14mph, my pebble is going off, I looked at the graph on the wheellog and it looks like the amp line spiked for no apparent reason???

I can't remember, why, but I recently turned off alarms and forgot to turn them back on. I didn't even know that the current monitor worked on the Z10.

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Just now, Marty Backe said:

I can't remember, why, but I recently turned off alarms and forgot to turn them back on. I didn't even know that the current monitor worked on the Z10.

maybe that's the issue, I am thinking of not using the alarms on my pebble, I have been a bit conservative lately and have no hills here to "Stress Test"... :)

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13 minutes ago, Marcglider said:

maybe that's the issue, I am thinking of not using the alarms on my pebble, I have been a bit conservative lately and have no hills here to "Stress Test"... :)

Exactly. I used the alarms more earlier as I was training myself to understand the loads better. They are still very useful to me when I'm going to be in high-stress scenarios like climbing steep mountains.

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2 hours ago, Marty Backe said:

You will always experience overload conditions when going downhill on a fully charged wheel. The this very ride, one of the guys was thrown off his Gotway wheel because there's a short downhill section at the very beginning of the 4600-ft climb. He was descend fast and the wheel overcharged and tilted back suddenly, literally throwing him off the the wheel.

On a previous ride the same thing happened to me, except I was anticipating it so I was able to smoothly step off the wheel.

So if you anticipate a somewhat steep downhill section at the beginning of your ride, don't fully charge the wheel.

Thanks! Good to know. Glad I asked. Getting thrown off in self defense I can live with as long as these things don’t explode under my feet. ? 

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7 hours ago, Toshio Uemura said:

could that overload and damage or even explode your batteries? Or are they protected from overloading in such a situation? Is this something to be careful about?

If I fully charged the 16S to 100%, it didn’t take more than a slightly stronger braking on a flat surface to make the overcharge alarm go off. If you live on top of a hill, you should never start by going downhill with a 100% battery.

The 100% charge is a hard limit, so any regen at that point will make the alarm go off, and hard tilt-back should follow very soon.

The hill people will have to have a method of discharging a bit after a balancing charge that takes all cells to 100%.

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7 hours ago, Jerome said:

I had no ideal what an amazing rider Marty is to jump from 14" wheels to 22" with a very modest adjustment period. I have been riding my KS18L exclusively for a couple hundred+ kilometers and have been ruined. For me going to the 18" inch wheel from the 16" inch wheel was "easy-peasy",. but going the other way .. not so much.

I had not ridden my 9B E+ since I got the KS18L and took it out for a short 3+ km ride to the bank. Oh brother! When  I mounted I could barely stay on and even after I got my balance, riding was very sketchy with the wheel flopping between my legs such that I had grip it with my shins. It was better on the return trip but not solid. I have actually ridden the 9B E+ more miles than the the KS18L, but you wouldn't think it. I am not sure it will work but I will take Toshio's advice and try and ride the 9B E+ after or in between KS18L rides. God forbid I try and ride a 14" or a MTen!

. Marty and other multi-size-wheel riders, I take my hat off to you!

And with the Z10 it’s even worse in the beginning. I recently ride my old and first wheel, the E+, quite often at the end of the day. It needs completely different muscle groups, since it is “flopping between my legs” as you well described it. I like this floppy feeling. The root feeling of EUC balancing. If you relax into it it’s actually quite nice and good exercise. But be careful when coming from more powerful wheels back to the E+. It’s easy to overlean when going uphill, since one gets so used to the strong torque and stable power of the recent wheels.

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11 minutes ago, Mark Lee said:

@Toshio Uemura with all of your positive posts on Z10, I got mine today... Got a deal I could not pass up... :D

??  Congratulations ??  ? I promise, you will not regret it! Lots of fun is waiting for you (after a few days of getting used to the beast) ? 

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4 minutes ago, Toshio Uemura said:

??  Congratulations ??  ? I promise, you will not regret it! Lots of fun is waiting for you (after a few days of getting used to the beast) ? 

I don't really have any problem riding this wheel like the others.  Reminds me of big Mten3... :w00t2:

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