Some first impressions and questions about my new ACM... (first wheel!)

[meepmeepmayer]

How is this formula motivated? 0.7 is the efficiency of the charger?

[Mono]

46 minutes ago, meepmeepmayer said:

How is this formula motivated? 0.7 is the efficiency of the charger?

Sorry, I should have motivated this directly. It is based on observations I made. Specifically, I have two 84V chargers and can observe the voltage change when plugging one or both. I see a change of about 1.1V for additional 1.5A current. For the 67V charger I see about 1.8V change between 0A and 2A current, so there the factor would be rather 0.9.

[US69]

3 hours ago, meepmeepmayer said:

How is this formula motivated? 0.7 is the efficiency of the charger?

Charging on our wheels works as follows...explained on a 67,2 wheel...

when you plug in the charger, the wheel will be loaded with the at time needed baterie voltage with full 2 amps...

when a specific voltage on the batterie is reached , about 90%=ca. 65 Volt....the charger starts to decrease the amperage slowly, increase voltage slowly and the balancing process starts ont the batterie....the charger then goes slowly up from about 65 to 67 volt, while the amperage delivered is going slowly down to nearly null.

at the end the batterie is at full state with all cells balanced.

this two different loading processes is also the reason, why the last 10% need more time than the first 10%

so as your wheel did not like to go higher than 88%...perhaps the charger has a generell to low voltage....or the BMS balancing process did not work....

But the later i do not think, as there a 2 BMS in your wheel...and these are connected ...and i dont believe both are defect.

 

if you would have a charge doctor, you can check the whole process, and perhaps would see whats the prob...

[meepmeepmayer]

@KingSong69 Charge doctor is ordered already! Did that yesterday. Do you have one? How long did it take?

@Mono said the batteries could need a few cycles until they are fully functional so maybe that's the case. Even though it looks like it's the charger. I had the wheel plugged in all the time and now it's at 91% -3 more than this morning!

--

I'm currently looking at how to protect the wheel (what is that "ridged" foam stuff everbody uses? All the people in the yt videos seems to use it) and myself (helmet, wrist guard etc.).

[Mono]

4 hours ago, meepmeepmayer said:

(what is that "ridged" foam stuff everbody uses?

https://www.aliexpress.com/item/U-Flat-Baby-Safe-Corner-Guards-Protective-Strip-Bumper-Widened-Table-Child-Protection-Strip-Thickened-Baby/32746658933.html?spm=2114.13010608.0.0.YNQrqD

http://www.ebay.ie/itm/-/322275030986

[Mono]

3 hours ago, KingSong69 said:

the wheel will be loaded with full voltage (67,2 volt) with 2 amps

though this voltage is not what we can see displayed with a voltage meter like the CD. And the displayed voltage also does not fully reflect the battery voltage, but is larger. That is how I suggested to subtract about 0.7 times the current to estimated the current battery voltage. 

[Grant Lanyard]

21 hours ago, Mono said:

The charge doctor is quite practical. If you have one with two inputs, you can use two chargers at the same time to charge faster. And you can prevent from charging up to 100%, which is good for battery life. There are not a lot of reasons to not have one for a wheel which was more than 1000 bugs bucks.

Where could I get one of these charge doctors?

[meepmeepmayer]

http://hobby16.neowp.fr/buy/

as seen on the previous page.

[US69]

1 hour ago, Mono said:

though this voltage is not what we can see displayed with a voltage meter like the CD

thats right.i am only seeing 67 or 67,1 volt...at the end...

[meepmeepmayer]

Wheel is at 100% - both wheellog and GW app! This is after I had it plugged in for a day. The EUC is ok!

I was informed that Li-Ion batteries don't really need any time to be fully functional, so it must be the charger. I'll update when the charge doctor is here and it gives some concrete numbers.

[Mono]

18 minutes ago, meepmeepmayer said:

I was informed that Li-Ion batteries don't really need any time to be fully functional, so it must be the charger.

What's the source of this information? This is what I believe a rather reliable source says about battery priming: 

Not all rechargeable batteries deliver the rated capacity when new, and they require formatting. While this applies to most battery systems, manufacturers of lithium-ion batteries disagree. They say that Li-ion is ready at birth and does not need priming. Although this may be true, users have reported some capacity gains by cycling after a long storage.

http://batteryuniversity.com/learn/article/how_to_prime_batteries

which may well fit with your experience. If your problem was the charger, how do we explain that the problem disappeared? 

[meepmeepmayer]

@MonoSource is confidential

I assumed the charger would slooooooooowly charge to full so that's why the issue disappeared (I charged for like 25h+ after the green light on the charger signaled it was done). But now with your link maybe it is the batteries. I'll see what the doctor says, no other way to find out. Should be here in a few days.

Good to know, if it's the batteries, that it's not a problem, just something that can happen. Thanks a lot!

[meepmeepmayer]

Update: just got the charge doctor. Voltage is 84V (sometimes 83.9, sometimes 84.1) and current is 1.56A. So everything is exactly as it should be (it went down to 1.35A, 1.25A, but that's probably because the battery is at 97% already)

I haven't really used much battery so I can only tell more after I do a charge from a lower battery percentage. The CD also counts up the Wh so you can see how much it charged then! Very cool.

For now, I'm assuming the first charge was a fluke and everything is good

--

Now for the bumper tape to arrive (and the ice slush and cold rain to go away)!

Also I learned what my dominant leg is and now there's a nice bruise there The (presumably cheap foam) Gotway cushion material looks elastic, but actually isn't - it gives in easily at first, and after that  it's just hard. No idea how it compares to other wheels, but it definitely does not feather as much as one might think from its thickness. Keep in mind I'm a beginner and probably press on the wheel too hard (and even without long pants) etc.

It's great fun though, even the little indoor practice makes you learn fast. For me, the best way is not to use a wall for balance, just start in the open until you manage to balance on the wheel. Harder at first but you learn what you really need to learn (self balancing, instead of trying to grab a wall). This great tip is from this video: 

 

 

[Marty Backe]

3 hours ago, meepmeepmayer said:

<snip>

The (presumably cheap foam) Gotway cushion material looks elastic, but actually isn't - it gives in easily at first, and after that  it's just hard. No idea how it compares to other wheels, but it definitely does not feather as much as one might think from its thickness. Keep in mind I'm a beginner and probably press on the wheel too hard (and even without long pants) etc.

<snip>

 

I think the Gotway padding is very nice. I agree that it feels kind of stiff when you are learning how to ride (I think because you press against it a lot). But as you progress in your riding skills you will discover that you don't apply a lot of pressure against the pads. So later when you're a pro (  ) the padding will feel very nice.

[steve454]

@meepmeepmayer great learning video you found, I wish I had seen that when I was first learning.  The idea of using a stick for balance to get on the wheel is great if there is no pole or wall to hold on to.  The audio is excellent, stayed the same volume no matter how far away from the camera.

[meepmeepmayer]

Yea that guy uses a good clip on microphone (you can see it some times). And while most learning videos wil tell you to start at a wall, no other I found tells you to stop doing that after a while (just like they tell you to stop using training wheels after a short time).

[US69]

On ‎03‎.‎02‎.‎2017 at 2:45 PM, meepmeepmayer said:

just got the charge doctor. Voltage is 84V (sometimes 83.9, sometimes 84.1) and current is 1.56A. So everything is exactly as it should be (it went down to 1.35A, 1.25A, but that's probably because the battery is at 97% already)

It should go down at the end to about 0,20 to 0,15A....And  then the charger should Change to green.

then all cells are perfectly balanced. No Need to do this on every Charge......

On ‎03‎.‎02‎.‎2017 at 2:45 PM, meepmeepmayer said:

Also I learned what my dominant leg is and now there's a nice bruise there The (presumably cheap foam) Gotway cushion material looks elastic, but actually isn't - it gives in easily at first, and after that  it's just hard. No idea how it compares to other wheels, but it definitely does not feather as much as one might think from its thickness. Keep in mind I'm a beginner and probably press on the wheel too hard (and even without long pants) etc.

:-) Thats all newbies challenge. The Gotway cushions are in fact on the better side.

But there will come the time, when you dont Need to "clamp" the wheel between your legs anymore. You will not even Need to touch it then....

[meepmeepmayer]

The funny thing is, I didn't get the bruises from riding, I got them from getting on the wheel. Balancing on it with one foot while keeping this 20kg weight from falling over is the hard part.

[Marty Backe]

2 hours ago, meepmeepmayer said:

The funny thing is, I didn't get the bruises from riding, I got them from getting on the wheel. Balancing on it with one foot while keeping this 20kg weight from falling over is the hard part.

We've all been there. It's the 'tax' you pay for entering this activity. Have faith that you will have a bruise free future :-)

[meepmeepmayer]

First outdoor ride done! After doing only some light indoor balancing and then being AFW (away from wheel) for the last week, today I rode up a road along a mountain creek valley, ca. 4km overall, average 8% incline (route see here: https://www.google.de/maps/dir/47.7628781,12.0151249/47.7474945,12.014384/@47.7545726,12.0061618,2464m/data=!3m2!1e3!4b1!4m2!4m1!3e1).

It went much better than expected. After 5 or so starts where I did only go a few meters, I was basically driving as far as I wanted without problem (it helped I didn't know how to brake that was "interesting"). I never fell, just had to step off a few times and the wheel did its slide and crash thing the next 1 or 2 meters. No damage to the wheel, just some scratches on the pedal metal.

About the ACM:

• I'm really glad I chose the ACM (over the Inmotion V8). It's just very stable and hard to damage (I added some foam padding though). I would have been much more worried about a glossy hard plastic shell.

Things I learned:

• You balance not by changing the weight on your feet, you balance by rotating your hip! Only a few learning videos mention that...
• Going fast is easier than going slow. Going uphill makes riding easier as well, I believe.
• Braking, how does it work? The hardest part was slowing down the wheel so the ride wasn't too fast! I did bend my knees (which shifts weight back) and I guess you can just lean back and must trust the wheel then (didn't try that much)
• Going downhill, holy **** It's harder than going uphill, especially if you have no idea how to brake properly. All my wheel "crashes" were while going down, uphill everything was perfect. All those ice patches and bumps that were hardly notable on the way up are suddenly imposing.
• The position of your 2nd foot on the pedal influences your entire riding and stability heavily. Do that badly and you don't go far. Tiny changes make a big difference.
• About clothing and safety equipment: I was very glad I had hiking shoes so no worrying about spraining ankles. So many people ride with low sneakers, that might end badly. Gloves are also good, you can use them to clean the wheel from dirt. Next step would be wrist protectors. Then, elbow protectors, knee protectors and a helmet (I had nothing)
• I'm glad I did not strap myself to the wheel. That spinning weight can stay away from me please. There was no danger of hitting other people/things or the wheel falling down somewhere, though, if that was the case I might use a strap.
• Going downhill does not seem to use battery (at this incline). I was at 83% on the top and at 83% at the bottom.

Photos: below are some photos. They show where I turned around because it was ice from then on. Also some impressions from the way back. As usual, it's steeper than it looks in the pictures (see 3rd pic for an idea).

[Marty Backe]

Congrat's on enjoying your new ACM. Looks like a nice riding spot, although cooooold. Everything you mention will just get better and easier with time. From my log book it took me about 10 hours before everything really clicked. Of course everyone learns at different rates. Enjoy.

[meepmeepmayer]

Thank you for the words of support. I did enjoy that. Even the adrenaline from the "I'm accelerating down a hill and have no idea how to brake" phases

Looks colder than it really was, it was like 5 degrees celsius and actually quite sunny and nice. The snow and ice is leftover stuff. Phone does not make very good photos so it looks dark and like Siberia or something similar...

[Slaughthammer]

For your braking problems, it might help if you imagine pushing your feet in front of your body for braking instead of leaning backwards. Just don't overdo it...

Otherwise, congrats for learning how to basically ride a wheel! Took me around 100 km until I was able to handle most maneuvers and situations smoothly, so take your time. Espeacially looking back while riding is very strange at first.

[Marty Backe]

3 hours ago, Slaughthammer said:

<snip>

Espeacially looking back while riding is very strange at first.

Or looking down 

[meepmeepmayer]

Thanks for your tips guys! Braking works reasonably well now.

I did the same tour today again, along with more driving in the flat and snow and incline tests. 15km added to the wheel! It went much better than yesterday, I didn't have a single crash or even the wheel falling, just had to step down a few times after a bad start. Also I realized the road was much steeper than I remember and that explains why going down was so complicated. Turns out, riding on a flat road is much easier!

The ACM is a great wheel. I never had to impression it was starting to be weak when going up 15% roads. Exactly what I wanted. So nice.

2 things that are the issue at the moment:

• basically everything depends on how well you step onto the pedals. You instantly know if it's going to be ok. Tiny changes of foot position make all the difference.
• turning, how does it work???? but I'm already getting better (I say that to myself)

I'm definitely addicted now.

Below is a snow test photo (turns out if the wheel sinks into the crusty snow and spins freely, you can't ride further but it's a great way to clean the tire), and you see what happens when someone parks their car on an inclined ice plate I don't have more photos as my phone did not make other good ones.