Looking for safe method to learn to accelerate hard?

[reach]

Hi.

it took me several 100km to get familiar with my V11. Right before I got it, I crashed with my V8 because I overleaned it.
It took me a while to gain enough trust to take the V11 somewhere close to 40km/h (that's really enough for me for the time being). Even worse so, because the 18" requires much more leaning than the 16".

Ok, so now I'm reasonably happy with my skills on the V11, BUT I think during acceleration I still leave most of its potential unused. Here I'm still held back by the very hurtful experience with overleaning the V8. My brain just doesn't allow more forward-leaning. 
The dream of course would be like Kuji does it, looking like Superman about to take off :-)

Does anybody know a good trick to improve? Be it riding technique, trick, or finding a forgiving environment where I might not hurt myself when I'm overdoing it? I seriously considered binding a pillow over my chest. Or maybe practising on a lawn, but there I'm not sure if grip might not be an issue.

Any tip would be appreciated. 
Thx, reach

[RockyTop]

Different direction- You over leaned the V8. …. How? What caused the cut out? A V8 has a top speed of 18mph? How close to 18mph were you when it cut out? The V8 has a VERY small battery. What was the battery level? I am not trying to trash the V8. It was a great wheel back in its day. It has always been too small for someone my size. I could not have faith in it. You see where I am going with this? The V11 is so much more capable. 

So to answer your actual question. You can slowly accelerate just a little more each time. Listen for the beeps or whatever warning the wheel gives you. Never do this above 20 mph or when the battery is low. I ride the acceleration beep on the KingSong 16s quite a bit. Starting from a stop I accelerate and then let off just a bit when I hear the beep. Then give it a little more until I hear the beep again. I call it riding the edge of the beep. I am not suggesting that you do this. I am just giving you an upper end example of what can be done. 
 

[Chriull]

1 hour ago, reach said:

Any tip would be appreciated. 

As @RockyTopwrote accelerate hard at low speeds and carefully at higher speeds. Best with full batteries!

If i not remembering falsely the V11 reports with the newer firmwares pwm duty cycle - which is the percentage how close one is to an overlean. EUC World calls this safety margin were 0% is overlean and 100% is no load.

If you log this value you can look how much reserves you still have!

For more detailed dry theory on overleans and this pwm duty cycle you can take a look at 

Edit: Kingsong have ?continous/5 consecutive? bees once 88% duty cycle are reached (12% safety margin)

Inmotion could/should have something like this?

Afaik the V8 did not have this warning.

Edited October 5, 2021 by Chriull

[reach]

13 minutes ago, Chriull said:

If i not remembering falsely the V11 reports with the newer firmwares pwm duty cycle - which is the percentage how close one is to an overlean. EUC World calls this safety margin were 0% is overlean and 100% is no load.

That's some great hint, thanks! 

To clarify: both my V8 overleans were when accelerating from zero. This is also my intention. Acceleration during riding isn't so much of an issue. At least not yet.

 

I do know that the V11 is much more capable than the V8 but that knowledge can't trick my brain&body into free-falling forward ;-) 

Tiltback + audible alert at topspeed works also well for me. I've never heard about a safety-margin alert. If the V11 had one, I suppose it would be adjustable, wouldn't it? However - checking the margin in the app is already a good start. Thanks!

[Chriull]

1 hour ago, reach said:

To clarify: both my V8 overleans were when accelerating from zero. This is also my intention. Acceleration during riding isn't so much of an issue. At least not yet.

 

Acceleration from zero is quite strong and one reaches high speeds very quickly - so one has high speed and acceleration which results in an overlean.

So the art is to reduce acceleration (lean) according to increasing speed.

Just looked it up again:

V11 reports pwm duty cycle and darknessbot and euc world read this value. So looking at the logs after a ride gives one an idea of what could still be possible.

But no.idea if inmotion has some alarm/tiltback based on this number...

 

[mrelwood]

1 hour ago, reach said:

That's some great hint, thanks!

It is a great feature! Perform an acceleration, then stop to see what the peak PWM was (at least in DarknessBot you can check this easily in the graph right away). If there’s lots of room to spare, accelerate a bit faster and check again. My guess is your first acceleration will be around 50%. You can aim for 70-80% if your feet feel secured to the wheel.

BUT, I think this really only applies to acceleration at speed, not at 0 mph. Most electric motors at 0 mph are tricky. If you try to launch from behind a fist sized rock, the motor simply can’t produce the thrust and the wheel will only tilt forward. This is also when the largest current peaks (and PWM utilization as well I think) are recorded.

But things change right away when the tire starts to rotate, so accelerating from 0 mph is no longer much of an issue at 3 mph.

Quote

I do know that the V11 is much more capable than the V8

2x - 4x more, depending on the V8 version. Unless you are very heavily built, chances are you will never be able to overlean the V11 of you wanted to (other than possibly stalling).

Quote

but that knowledge can't trick my brain&body into free-falling forward ;-)

PowerPads to give support to my legs helps me tremendously in trusting the lean. No matter how powerful a wheel is, I wouldn’t lean on it very hard when even a small bump could disturb my balance that is already in a compromised state.

Quote

I've never heard about a safety-margin alert. If the V11 had one, I suppose it would be adjustable, wouldn't it?

No, it’s not there for the user to toy with. It exists to warn when the wheel is nearing its limits. The wheel knows them better than the user.

Edited October 5, 2021 by mrelwood

[Tawpie]

Until very recently I rode without pads, so fast acceleration meant trying to adopt superman poses. And like the OP, the lizard brain isn't happy. What I've found interesting with pads is that I can kind of "sit down" into the push pad and keep what feels like my center of gravity closer to the wheel's axle while using dorsiflexion (love that word) to apply acceleration leverage. I really don't think it's particularly stable, the hard contact points on the shins mean small bumps toss me around a bit. But it does give that extra boost feel to the takeoff without seeming like I'm about to fall off the front. And if I overlean it, I'm still on my face... but it adds a half-a-zoom to the zoom zoom.

[rcgldr]

Note that the V8F doesn't report PWM (it doesn't show up in EUC World). I weigh 190 lbs and just accelerate and brake conservatively since I have no clue as to how close to overlean I am. Video of a of a V8F cutout on acceleration test from a slow rolling start. It cutout at a fairly low speed, so the rider was OK. In this case, the V8F wouldn't power on again, and someone commented that one of the fuses was probably blown.

https://www.youtube.com/watch?v=hAEOnvDNaYw&t=750s

 

Edited October 11, 2021 by rcgldr

[mrelwood]

6 hours ago, rcgldr said:

Note that the V8F doesn't report PWM

But it does show amperage and wattage. Unlike the phase current that Gotways report, on an Inmotion they are actually useful numbers.

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I weigh 190 lbs and just accelerate and brake conservatively

And that is absolutely the most sensible thing to do. But if your “conservatively” is anywhere near what my “conservatively” used to be, there could still be ample headroom left for the whole village. If not for anything else, I’d check the currents and wattage for peace of mind.

Quote

Video of a of a V8F cutout on acceleration test

Here’s an idea: Take a similar video of your conservative maximum acceleration, and compare a screenshot of your most aggressive acceleration with this one from the above video:

 

If you are getting close to a lean like that, then best not to push any further. 

The V8F is not a wheel to do repeated acceleration tests like that with, that much is obvious. Blowing a fuse is not the most graceful way for the wheel to handle things, but the manufacturer had simply calculated that with currents like this, the board is about to fail anyhow.

 

Edit: Last week I found a really nice, really short, but really steep path that was very joyful to ride up and down. It was steep enough that I did wonder if I’m pushing my V11 a bit too close for comfort. So I let DarknessBot run while I crawled up the incline. Result: PWM < 19%, wattage < 1100W, temp 50•C. Safe maximums would be about 80%, ~4000W, ~90•C. 

So there is “conservative”, and in my case there is “ridiculously conservative”.

 

Edited October 12, 2021 by mrelwood

[rcgldr]

2 hours ago, mrelwood said:

But it does show amperage and wattage. Unlike the phase current that Gotways report, on an Inmotion they are actually useful numbers.

I don' t know what the maximum safe amperage and wattage values are, so I'm pretty conservative. The V8F motor is listed at 1000 watts nominal, 2000 watts peak, and I've seen a few times where the peak was around 1150 watts (testing tilt back at 25 kph on a slight incline), or -950 watts (testing tilt back at 25 kph on a slight decline) without issue. In the video of the V8F cutout, the speed wasn't that high, so it was a current issue (versus power), probably blowing a fuse as commented on the video. I slow to less than 20 kph for slight inclines or declines on a nearby paved bike trail, and around 15 kph for a 6 degree slope near my home.

Edited October 12, 2021 by rcgldr

[mrelwood]

4 hours ago, rcgldr said:

I don' t know what the maximum safe amperage and wattage values are, so I'm pretty conservative. The V8F motor is listed at 1000 watts nominal, 2000 watts peak, and I've seen a few times where the peak was around 1150 watts

If the motor has been announced as 2000W peak, your peak of 1150W does indeed have a lot of headroom. For amperage I would assume at least a 30A fuse on board, so peaking at 25A shouldn’t be an issue.

I think the peak power of the V11 motor was announced as 3500W, but Inmotion have themselves said that the peaks can be over 5000W for a short period of time. And that’s on a 2200W nominal motor. I see peaks of around 2600W when riding “calmly“, and I haven’t had the guts to get it past ~3700W when riding aggressively.

Edited October 12, 2021 by mrelwood

[Eucner]

Peak power is meaningless if duty cycle (on and off times) are not also specified.

[.....]

Dunno if applies to your model of euc, but I use eucw with 20% safety margin beep. Now I don't know how accurate it is. I don't know if it reacts fast. All I know is it makes me nervous when I hear it beep. I typically see it warn me when I lean like a dumbass tho I'm already traveling at 75% of either wheel's top speed. I always top full charge before a ride day, even a short one. It aint distance Im paying for, its headroom. I'm try not to get the beeps on accel from stop, but it happens. I'd say the only REAL safety measure that we can count on, is our own habits, and we KNOW those aint an exact science. My time is coming, but I've yet to overlean one at speed. Still gots me front teef too!

Edited October 17, 2021 by ShanesPlanet

[rcgldr]

On 10/13/2021 at 3:14 PM, ShanesPlanet said:

I always top full charge before a ride, even a short one.

I only do short rides that use about 10% to 15% battery (sometimes I'll do 2 short rides on the same day after charging to 100% and balancing the night before). I'll probably be only putting 1000 to 1200 miles a year on my V8F, so maybe I shouldn't be so concerned about having the batteries charged to near 100% most of the time between rides?

[Tawpie]

6 hours ago, rcgldr said:

I only do short rides that use about 10% to 15% battery

You would be fine going several days between charge-to-100% plus balance. The bulk of my rides are shorter and I let it get down to about 50-60% before I recharge. It does take some measurable life from the cells to have them at near full charge all the time, but in the long run I seriously doubt you'll notice. The most important thing is to balance them when you do charge them!

[.....]

12 hours ago, rcgldr said:

I only do short rides that use about 10% to 15% battery (sometimes I'll do 2 short rides on the same day after charging to 100% and balancing the night before). I'll probably be only putting 1000 to 1200 miles a year on my V8F, so maybe I shouldn't be so concerned about having the batteries charged to near 100% most of the time between rides?

90% of my rides are less than 10 miles. Most are <5 miles. Even on my Sherman, I top it off after each trip for the day. My ability to sag the battery down to below 50% within mere blocks, and the constant threshold warnings within the same distance or less, tells me to keep that battery as full as I can. I also do the same on my 67v mten. I mean sh*t, its obvious that it doesnt have a single watt of headroom to spare. I dont ALWAYS top off my 18xl, until it gets below 80% or so. It seems to have a more conservative top speed and I ride it like a scared little boy anyhow. Theres NO WAY I'm going to mitigate the batteries in any fashion that is worse than other wear and damages that will eventually happen. If i have battery problems, its from crap manufacturing, not overuse or mistreatment. Or its from a heavy crash. Maintain your wheels how you see fit, but I am constantly more in fear of sag and overlean causing severe wheel and personal damage, than the slight degredation of battery capacity over a VERY long timeline. I charge slowly and wait for them to cool before doing so. Batteries arent for range in my point of view. Batteries are for headroom and the maintaining of a ride how I WANT to ride, not how the wheel tells me to. The ONLY reason I sold my beloved 18L for an 18XL, was headroom. I only rode my 18L down to throttling, twice in 2 years. However, I hit headroom beeps quite often. The extra capacity of the 18xl didnt mean I ride further or faster. It simply means I dont hear the beep of death as often. Ironically, MY 18XL is the older version with the exact same powered motor as the 18L. Tbf, I preferred the build quality of the 18L a wee bit more. Compromises on everything, even on simpler designs.

Of course, ALL of this is just personal preferance. Maybe you dont ride like I do? Maybe I'm overly paranoid. I have nearly no baseline for comparisons, as I ride alone 99% of the time. All I know is that no matter what I do, the euc seems tame in compare to my bikes. Probably more dangerous tho, so it does carry a lot of excitement.

Edited October 17, 2021 by ShanesPlanet

[Planemo]

2 hours ago, ShanesPlanet said:

My ability to sag the battery down to below 50% within mere blocks

Jesus. I know mine sags a bit but you must be seriously hardcore to hit 50% sag within a few blocks 

[.....]

47 minutes ago, Planemo said:

Jesus. I know mine sags a bit but you must be seriously hardcore to hit 50% sag within a few blocks 

I keep hearing similar comments. Perhaps there's something wrong with my wheel. I should do a proper range test, check to see how many AH it takes from near empty (to fill).  I am pretty sure I'm not using custom voltages in eucw. Surely MY 130lbs newbie a** isnt doing anything special or more than most riders. Now you guys have me worried....

[Planemo]

58 minutes ago, ShanesPlanet said:

I keep hearing similar comments. Perhaps there's something wrong with my wheel. I should do a proper range test, check to see how many AH it takes from near empty (to fill).  I am pretty sure I'm not using custom voltages in eucw. Surely MY 130lbs newbie a** isnt doing anything special or more than most riders. Now you guys have me worried....

Well, it's difficult to tell how hard you're riding without riding next to you. And if you don't do enough mileage to get a feel for the available range then thats not much help either. Potentially the wheel is fine and you're just hammering it more than you think. But 50% does sound like an awful lot, almost like it's just running the packs on one side!

It would also fit with the fact that I see around 20~25% sag max as far as I recall, but to be fair I haven't given the wheel what I consider to be a right proper hammering yet either.

[Planemo]

Actually, I just had a look at some of my EUCW data for a section of ride I remember recently. It was an uphill asphalt stretch of about 3 miles gaining around 500 feet, I was only sitting at around 30mph as it was blowing a hoolie right down me nose all the way, I was struggling to go much quicker tbh due to wind speed.

At the start, 73%. The lowest it dipped was 53%. So yeah, about what I thought - 20%. But I believe I have seen 25% at some point before.

Not the best dataset I admit given the relatively short run, but just for info.

[.....]

34 minutes ago, Planemo said:

Actually, I just had a look at some of my EUCW data for a section of ride I remember recently. It was an uphill asphalt stretch of about 3 miles gaining around 500 feet, I was only sitting at around 30mph as it was blowing a hoolie right down me nose all the way, I was struggling to go much quicker tbh due to wind speed.

At the start, 73%. The lowest it dipped was 53%. So yeah, about what I thought - 20%. But I believe I have seen 25% at some point before.

Not the best dataset I admit given the relatively short run, but just for info.

I HAVE to be confusing the numbers. I'm seeing sag down to mid 80's after a mile or two from 100%. Not hard riding, but not easy. This sounds about right. I'm pretty sure I've seen much worse, but its typically after a mile or two of high speed uphill sweepers. The voltage bounces back quickly as well. Its the 'safety margin' of 20% that I keep banging the crap out of under just normal riding. That and over voltage when doing e-stops from 30+ mph. Man I luv those I am not sure if I've ever heard the actual wheel itself beep. Maybe once, but I'm not sure. Eucw is my alarms and compared to the wheel, they are ultra conservative imho. I figure Veteran is like Gotway. It tells you you've gone too far, as its bouncing down the street with you behind it.

I SHOULD let my sherman get down to 10-20% battery and THEN do some accell testing. See if it warns me before I break my face. I wonder if "safety margin" would peep at all, if it was set at 15% and I donkey leaned at 20% battery. ONly ONE sure way to find out and I'm just not in the mood to drink enough for it.... yet.

Edited October 18, 2021 by ShanesPlanet

[Planemo]

I use EUCW for alarms too. I don't think I have ever hit the safety margin or over current alarms tbh. At least, theres no blobs on the EUCW graph to show any trigger points. I do get loads for current though, but I am still playing with my current alarm settings. I have now upped it to 45A, 90A peak although I'm still not sure thats right as I haven't ridden on it yet with those settings.

I still can't get my head around the safety margin alarm, nor do I know how to interpret the EUCW graph for it.

I have never heard the wheel beep. I like that

So you're seeing around 15% sag after a mile or two of 'spirited' riding. Doesn't sound nearly so bad now! 

[mrelwood]

For reference, when the 100V MSX came about, EVX published a video where they were doing acceleration tests on a few different MSX models. The 1200Wh 100V MSX went down all the way from 100% to 0% during a single acceleration.

All the EUCw does is to show the information that the wheel itself provides. I wouldn’t be surprised if there is a big difference in how the wheels report the voltage. Some could be more real-time than others.