Got an old A2B ultra motor for free. Is it worth fixing?

J

Jeffreynmandy

1 mW
Joined
Apr 16, 2017
Messages
18
Hello. I'm new to electric bikes. The main use for us will be campgrounds. this bike was thrown in for free when I bought a like new pedego cruiser for $900. The a2b has sat for atleast a year.

Im going to consider the batteries shot, and the tires are bad. He also said you have to tap on the throttle sometimes to make it work. Other than that it was in good working order when he parked it.

what are some ideas for it? I'd like to make a a2beast project with it, but the cost and my skill may not let that happen. What would be needed to just get it going again? Or is it even worth fixing, considering it needs tires, battery, and possibly more?

Summary: free a2b ultra motor bike. It has a bad battery, tires, and throttle. What's the best, economical way to get it going again. And if the needed parts aren't outrageously priced, I'd like to upgrade for speed/range.

 
have a read through this, https://laebike.com/blogs/builds/73206085-a2b-metro-more-like-a2b-monster-6600w, and decide how much you could/ want to do...

edit: actually, watching the video, not sure I would want to be on a A2B at 50mph! :D
 
What do you mean is it worth fixing what are your alternatives exactly?

I wouldn't fix it I would sell it and do a build off a badass downhill bike but that's just me. Your needs may be different. If you just want a bike to mess around with and are mechanically skilled it could be well worth fixing.

The hub motor looks pretty big.
 
Probably everything you need to know in one or more of these threads:

https://endless-sphere.com/forums/search.php?keywords=a2b&terms=all&author=&sc=1&sf=titleonly&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search


AFAIK the Stromer also uses the same motor (with internal controller):
https://endless-sphere.com/forums/search.php?keywords=stromer&terms=all&author=&sc=1&sf=titleonly&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search
 
flat tire said:
What do you mean is it worth fixing what are your alternatives exactly?

I wouldn't fix it I would sell it and do a build off a badass downhill bike but that's just me. Your needs may be different. If you just want a bike to mess around with and are mechanically skilled it could be well worth fixing.

The hub motor looks pretty big.
Click to expand...


I meant would the cost of fixing it exceed the value of it. Kinda like when they total a car. I don't really know if parts are available. I saw the stuff on la ebike but they don't show any parts as in stock.

I did some searches, but couldn't really find what a current value would be on it.
 
All you have there is a frame. Forget the motor, it looks beat up. The swingarm may obviate the need for torque arms which would be really nice.

Anyway, I would say if the suspension and stuff is good AND IF THE BIKE FITS YOU (critical, forget it if it doesn't) you can go ahead and use it on your next build and come out a little ahead. From your posts you obviously know nothing whatsoever about bikes so you might take it to a shop and have them inspect it.

Anyway, here's a rough budget for a build you will actually enjoy, vs thinking "well that's kind of cool but I wish it went faster / farther":

Tires + tubes + rim tape: $80
Powervelocity 18F sinewave controller: $180
Leaf 1500W rear hubmotor: $300
Domino Throttle: $100 MUST HAVE
1KWh high performance 18650 Battery: ~$600 (don't skip on battery you will regret)
Charger: $200
Cycle Analyst: $130 MUST HAVE
 
flat tire said:
All you have there is a frame. Forget the motor, it looks beat up. The swingarm may obviate the need for torque arms which would be really nice.

Anyway, I would say if the suspension and stuff is good AND IF THE BIKE FITS YOU (critical, forget it if it doesn't) you can go ahead and use it on your next build and come out a little ahead. From your posts you obviously know nothing whatsoever about bikes so you might take it to a shop and have them inspect it.

Anyway, here's a rough budget for a build you will actually enjoy, vs thinking "well that's kind of cool but I wish it went faster / farther":

Tires + tubes + rim tape: $80
Powervelocity 18F sinewave controller: $180
Leaf 1500W rear hubmotor: $300
Domino Throttle: $100 MUST HAVE
1KWh high performance 18650 Battery: ~$600 (don't skip on battery you will regret)
Charger: $200
Cycle Analyst: $130 MUST HAVE
Click to expand...


Thank you for the help, this is exactly what I'm looking for. There is a big bike shop about an hour from me, but I don't know if they do any custom type work on electrics. They do build batteries.


I'll talk with them today about it. I could probably do the work myself as long as it's mainly replacing parts. I have a fair amount of tools. I just wouldn't feel comfortable trying to open the motor or do any circuit board work.
 
You can see what I did with mine:
https://endless-sphere.com/forums/viewtopic.php?f=6&t=50590

If you just want to make it run with the least amount of work/expense, you can mount a battery on the rear rack and tap into the secondary battery connector. You could pull out the frame pack, but it's a chore and easy to mess up the wires in the little compartment under the bottom bracket.

I have another one that looks almost just like the one in your picture. Dead pack, flat tire. I plan to remove the battery and rebuild it with new cells.
 
I am also starting to rebuild a 2013 A2B metro w/b battery. This bike is one of my favorites and I would like to change most of the things on the bike lol.

Has any one tried switching the Direct Drive motor for the newer 500/750watt Gear BAFANG Motor instead of the 500w Direct Drive Motor? I know the rear drop out is about 150mm.
http://www.szbaf.com/en/components/component/motor/rm-g060750dc.html
http://www.szbaf.com/en/components/component/motor/rm-g060250dc-1.html
http://www.szbaf.com/en/components/component/motor/rm-g040500d.html

fechter post was very helpful, thanks
 
I went to the bike shop today and let them take a look at it. Around $800-900 to get it going with the original motor. Rebuild the battery, new tires, fix the throttle and clean it up.

Probably get near 2,000 for a full rebuild. This shop is right in the city and the main business is ebikes.


What broke my heart though, they had a new 2013 shima they said they would sell me for $1600. I don't really want to put that much money into an old bike if a new one can be found for close to the same price. They said they would warranty it also.

Is that normal for ebikes to be sold that far below msrp? I know the pedal assist only could hurt the appeal but still.
 
If it's from 2013, the battery is at least four years old.

That's the biggest reason even a "new" old ebike would not be worth it's original price.

Depending on the kind, it's going to be less capacity than when new.

Worst case, if it hasn't been kept charged now and then, and has a BMS, the BMS may have run at leastsome of the cells down below LVC, meaning it will require either manual balancing, or possibly even replacement cells.

If it is SLA and not kept charged it'll need new ones.
 
Although I love my A2B Metro, I went out and Purchased a Radmini Electri Folding Far Bike. It wasn't cost effective to rebuild but I am going to do it any way because I love the frame so much. It Really is a Heavy bike that needs to be lighten just a bit.
 
ZenStar said:
Although I love my A2B Metro, I went out and Purchased a Radmini Electri Folding Far Bike. It wasn't cost effective to rebuild but I am going to do it any way because I love the frame so much. It Really is a Heavy bike that needs to be lighten just a bit.
Click to expand...


I've got the motor and wheels off now. It's way lighter with just those off. A lighter motor and battery would make a difference I think.

I have a lot more time than money, so I'm going to try to rebuild this one. And it's hard to justify that much for a campground bike. The parts are expensive though.

I don't know if I'm going to tackle removing the battery today or tomorrow.
 
Taking the battery out only took a few minutes. Luckily it had a cord around the battery, so it pulled right out.


I read some of them could be pretty hard to get out.
 
Jeffreynmandy said:
I've got the motor and wheels off now. It's way lighter with just those off. A lighter motor and battery would make a difference I think.
.
Click to expand...
Hard to find a battery much lighter than that 12Ah , 18650 cell pack that is standard, and that motor is not much heavier than any other 500-750W DD hub ( with controller) that you might replace it with.but if you can settle for the sound of a gearmotor, you may save a few lbs
The Metro was built a a tough city bike, not a lightweight traveller.
If it doesnt suit your needs, sell/swap it for something more suitable....it is worth a few bucks if you can get it running.
 
You could weigh the motor and rear wheel now that you have it off. You could then check weight specs on other motors to see if they are lighter. Not sure what the rim and tire weigh, maybe 1-2 lbs. For the power rating, the stock A2B motor is fairly light but the internal controller sucks.
 
Motor and controller are built into the rear hub if I'm not wrong

Sent from my SM-G925I using Tapatalk
 
Should I just leave the internal battery out, and go with something removable on the rear?

I ask because the bike will be stored in in my metal building workshop that isn't heated or cooled. It can get around 100 degrees F in the summer and around 30 in the winter.

Will those conditions significantly affect the battery?
 
dventu said:
Motor and controller are built into the rear hub if I'm not wrong
Click to expand...
That's correct on the older models. It's prone to overheating and shutting down.

As far as battery storage, high temperatures are definitely bad for battery life. 30 in the winter would be fine.
Since I built a big secondary battery I carry on the rear rack, I almost never use the frame pack. It's my emergency backup or range extender. It might work well to just leave the frame pack out and use a detachable battery. It would be a significant weight reduction.
 
flat tire said:
All you have there is a frame. Forget the motor, it looks beat up. The swingarm may obviate the need for torque arms which would be really nice.

Anyway, I would say if the suspension and stuff is good AND IF THE BIKE FITS YOU (critical, forget it if it doesn't) you can go ahead and use it on your next build and come out a little ahead. From your posts you obviously know nothing whatsoever about bikes so you might take it to a shop and have them inspect it.

Anyway, here's a rough budget for a build you will actually enjoy, vs thinking "well that's kind of cool but I wish it went faster / farther":

Tires + tubes + rim tape: $80
Powervelocity 18F sinewave controller: $180
Leaf 1500W rear hubmotor: $300
Domino Throttle: $100 MUST HAVE
1KWh high performance 18650 Battery: ~$600 (don't skip on battery you will regret)
Charger: $200
Cycle Analyst: $130 MUST HAVE
Click to expand...


What kind of speed and range is possible with that set up? And if I get the internal battery rebuilt what's the most I could squeeze in there as far as amp hours? The guy at the bike shop said around 10-12 amp hours.

They want to sell me a new bike but I'd like something more custom as far as speed. The shop said it's $3,000 and up to buy a bike that goes faster than 28mph.

It seems like I'd come out a good ways ahead if I build this one for around $1500.
 
Mine goes about 28mph with a 14s (52v) battery. I goes faster if I use field weakening on the controller. My A battery is still the stock 36v that gives me around 20mph. With an external controller, I've seen guys push them to 72v. Too fast for me.

If you get a whole new motor, then there are options for what wind you get. Faster ones have less torque for climbing.
 
fechter said:
Mine goes about 28mph with a 14s (52v) battery. I goes faster if I use field weakening on the controller. My A battery is still the stock 36v that gives me around 20mph. With an external controller, I've seen guys push them to 72v. Too fast for me.

If you get a whole new motor, then there are options for what wind you get. Faster ones have less torque for climbing.
Click to expand...

The motor is probably still good, I was just going to replace it while I have the bike apart. I like speed, I have a golf cart that I've hit 40mph on.

My knowledge is more with golf cart motors and controllers. 48v of battery has to have a 48v controller. Could I just put 48v on the old motor/controller and expect any life out of it? While I'm getting the battery built I just didn't want to regret getting a 36v battery If it doesn't up the speed.


I've got a lot of studying to do, it seems pretty complicated just starting out.
 
So believe it or not my setup

Powervelocity 18F sinewave controller: $180
Leaf 1500W rear hubmotor: $300
Domino Throttle: $100 MUST HAVE
1KWh high performance 18650 Battery: ~$600 (don't skip on battery you will regret)
Charger: $200
Cycle Analyst: $130 MUST HAVE
Click to expand...

topped out at 56 MPH...your salesman's world is quite different from what's achievable with DIY. So my battery was higher voltage--19S (80v peak, 70v nominal) even though the capacity wasn't super large at 800Wh. If you use a more common, lower voltage battery like 14S you can still do 40+ mph top and the maximum efficiency will be somewhere around 30 mph so perfect for cruising. That's the beauty of an efficient and powerful hubmotor like the Leaf paired with a powerful, efficient controller and powerful battery. Oh, and the torque from a stop? If you want to, you can program enough of it for power wheelies...:D.

Yes, it's true that ready made ebikes represent TERRIBLE value for money. Unless you're rich, you will not get the performance you want out of an ebike except if you build it yourself.

You basically need a new battery. If they're "rebuilding" it they're reusing the case and maybe the BMS. You can build a battery yourself, buy one from a member here, or buy a ready-made battery from a reputable site like ebikes.ca or lunacycle. One thing's for sure, put good name brand cells in it like Samsung 30Q or 25R and you'll be really happy. The cheaper the cells you put in the more voltage will sag under load, reducing your performance.
 
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