A2B Metro (Gen 1) Restoration and Upgrade

I replaced the freewheel on mine with a new one that was the same tooth count as the original. I really can't hear it much.

You really want the pedals to work if you want to avoid issues with stupid cops. Also handy when the electric drive fails. On mine, I can assist the motor up to about 20mph in top gear. Beyond that, I just ghost pedal to keep the cops happy.

I can tell from your Whr/mi that you were having fun. If you keep the speed down below 20mph, you should be getting closer to 20Whr/mi and you can ride till your butt hurts.

Cool, maybe a video on your next run? Some panniers over the batteries would look the business I reckon. I agree, pedals are a must or do you live in an area where it’s not a requirement? I know Ultra motor made an A2b excel with foot pegs if you can find one. The joys 20inch wheels, I fitted a 70T and that barely helped.

Audisport09 said:

Some panniers over the batteries would look the business I reckon.

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Would "stealth" the bike quite a bit.

Audisport09 said:

I agree, pedals are a must or do you live in an area where it’s not a requirement?

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CA, Bay area -- extremely lax enforcement, soooooo...

Audisport09 said:

I know Ultra motor made an A2b excel with foot pegs if you can find one.

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Wow, I had no idea, but that's pretty wild.





It's like they attached EUC pedals to the frame. Hrm...

Even if I could find one, it looks like that's welded to the frame, so not something I could just swap out.

Cool, I've never seen one like that. Around here it would be legal on the street, but not on the trails. You'd be sort of screwed with that one if you hit any kind of hills like I deal with. Great for flat ground.

I believe I read it has a higher power out, not sure. You could maybe buy some unicycle pedals and attach them somehow. I saw a white one once for sale here in UK going really cheap, I guess no one wanted it because of these stupid laws. If I could go pedal less it would have to be the BREKR MODEL B. Dream bike, attaching pedal would be a nightmare I imagine.

Yes, the A2B Excel was labelled/sold as an 'Electric Scooter' and appears to have been fitted with an 800W version of the UltraMotor.
I guess the controller was in the frame:

E-Glider said:

Yes, the A2B Excel was labelled/sold as an 'Electric Scooter' and appears to have been fitted with an 800W version of the UltraMotor.
I guess the controller was in the frame:

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It says main battery 48v, so that's how they got more power. I ran mine at 52v for a year before I did the external controller.

Ended up putting a chain back on, but I also picked up a shimano freewheel to replace the DNP hoping it would be quieter (reviews said it would be) and it definitely is.

[youtube]WRDXw5VUov0[/youtube]

And it's even better once mounted on the bike. I doubt it'll be audible at all once I'm moving along.

Dang, went for a ride, flipped the lights on and the dc/dc stepdown blew out -- tripped the acc breaker AND the battery breaker. Wasn't playing around with it's internal short, sheesh. Second setup using Fulree converts which has died on me.

Good thing you had breakers that worked. Otherwise it would have been a fire.

Can you post a picture of the bad dc-dc? I want to make sure I don't buy one like it.

Yeah, the breakers came is SUPER clutch here, was able to reset the battery and controller side and still ride. I can live without the phone charger



I've also had some of these that have lasted years and plenty of other folks without issues too. Dunno, half wondering if I've done a poor wiring job or something. It's hard to find dcdc converters that actually work at the 60-84v range, and a lot of the ones that do are just massively too large.

I'd suggest a separate fuse for the dc-dc. Once you get up to around 72v, you can start using power bricks made for AC line voltage. They are not as compact though.

Gonna give this one a try. Didn't immediately fail, so yay. (The neoprene I added to keep it from bouncing around to much in the bike body. No real way to secure stuff in there :/)

fechter said:

I'd suggest a separate fuse for the dc-dc

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Got that, actually what saved me being stuck.

where did you get those breakers?

https://www.amazon.com/gp/product/B000MMH27U

Technically, a little under rated (65v dc) for my purposes, but have proven to work great in practice. Obviously

The housing is something I whipped up and 3d printed to fit the oval'ish shape of where the controller on the bike used to be.

Thanks for the link. I like the size of those. I think the voltage rating isn't going to be a problem. Close enough.

Forgot to post this! I took some scrap 1/4" aluminum and cut it down to size, drilled some mounting holes in it, and ran it across my table saw to put "fins" on it. Bought myself a rivnut to put some extra bolts in and now I have a nicely tucked away, but airflow excellent phase runner.







----

The bikes been holding up great. I added a taller handle bar to relax the sitting position a bit, which required redoing all the brake lines. Last time out the fender snapped itself apart (old plastic combined with some really bad back streets just were too much) so I pulled that off. Literally just snapped it off because getting to the two screws on the frame require pulling the whole rear motor off -- no thanks!



I also have found the holy grail of chargers:



This bad boy has adjustable amperage (0 to 50A), adjustable voltage (0-120v), and can automatically switch between 110 or 220 inputs voltage. (This means you can plug it into a J1772 EV adapter without blowing up your charger you forgot to change the 110 switch on...not that I've done that TWICE now or anything...)

On a 110 outlet, it can run a total of 1500 watts and that doubles to 3000 watts on a 220. To put that in perspective, with an 84v top charge rate, this could pump out 35A charge rate -- on 90% of things would just set them on fire, lol. Gotta be careful with it! It's not much heavier than most fast chargers, but the form factor is actually a lot nicer as it fits in a flat panier much more easily.

Whipped up an XLR connection for it along with an anti-spark for hooking everything up:



One of the long rides I went on, where I definitely didn't explode my charger 35mi away from home, I discovered that the absolute maximum range of the bike is 50mi. The last 5, though, are awful. So, a realistic 45.

Where did you get that charger? Can you post a link?

I've done some pretty long rides on my A2B by going slow. My butt was starting to hurt toward the end.

fechter said:

Where did you get that charger? Can you post a link?

I've done some pretty long rides on my A2B by going slow. My butt was starting to hurt toward the end.

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I had a read, you can get them here I think.
https://www.aliexpress.com/item/33036575847.html?spm=a2g0o.productlist.0.0.671e3bbaRksGNX&algo_pvid=f3753dc8-06ec-46dd-a0da-704699203241&algo_exp_id=f3753dc8-06ec-46dd-a0da-704699203241-1

I wish they would make a higher voltage of the Mean well HLG-600H. Waterproof and fanless, can't be beaten Imo

Audisport09 said:

I had a read, you can get them here I think.
https://www.aliexpress.com/item/33036575847.html?spm=a2g0o.productlist.0.0.671e3bbaRksGNX&algo_pvid=f3753dc8-06ec-46dd-a0da-704699203241&algo_exp_id=f3753dc8-06ec-46dd-a0da-704699203241-1

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This looks about right.

Had to scavenge parts from this build over the last year for other projects but realized I kinda missed this bad boy. I also figured I likely have enough parts around to get it up and running again and that it's easier to sell something that works than parts

I decided I wanted to have a short-trip fun-runner; so I'm rebuilding the downtube battery in 72v with molicel p26a cells. 20s3p, technically capable of 35x3== 105A, but I'll stick with 20x3 for 60A. As I'll be chopping off the BMS portion of the battery holder ABS shell (to fit in a new BMS), I figured I should get some shots of this thing in various states of disassembly for posterities sake.

In absolutely no particular order:

Got the battery all sorted out. 20s3p:







I'm very happy with how this came out. It then got wrapped up in the original shell, which I did have to chop down a bit after removing the BMS, and put back in the case.

I thought I would use a "1200w fat bike" motor I bought, but then I decided to open it to dump in some statorade only to discover it was made with a 25mm magnet/stator! There was 45mm of space in there! Looked super anemic with that thin strip of magnets in it. Come on!

Also was given an ebikeling motor (non-fat width) from a friend's abandoned project a while back. Figured I should check out that motor as well...and it was rocking 35mm! Well, clear winner.

So, I measured it out, used the grin spoke calc, and built the 35mm motor into a 20" rim. Got that all mounted up, wired up as little as possible (motor, battery, bms, charge port, throttle) all into a Flipsky 75100 (the $100 version) and started bopping about. As made apparent in this very long thread on the 75100, it really can't push more than 60ish phase amps. Which is a big let down, because I said "frock it" and cranked it to 150 phase amps and yoooooo boy, that was the acceleration kick I was really hoping for from this bad boy.

So I shelled out for a 75200 which has at least one highly positive review so far. The 75100 will go to my Kona rebuild.

What other little things:

• Tried out some "bottom bracket pegs" I bought a while back. They're pegs, but they've got BB threading and you just screw them in. Turns out where the BB bracket sits isn't the most ergonomic place for your feet to hang out.
• Put a basic single speed drive train back on -- you can pedal, but let's be real -- not far
• Had to find a rather specific helicoil repair kit for the derailleur hanger which I'd stripped out the M10x1.0 thread on so I could hang a chain tensioner
• 3d printed a bottom plate for the downtube so nothing will get all up in there

Spent some time to 3d printing a kinda-ok-ish enclosure for the controller. It's certainly not water tight or anything, but should do the trick well enough.

Also got the metr installed so I can start doing some runs with analytics.





Installed an AS150 (anti-spark 150A) connector to do a slow-engage of the caps. Go figure the first one I used the built-in resistor was fried from the factory and I didn't test it. Well, I mean, I tested it the hard way with a surprising full 84v spark, which is great.

I'm...really disappointed in these AS150's. They are quite a bit more expensive than XT90-S, and for an "8 piece" kit you only get 2 actually anti-spark plugs; the rest is 4 female connectors and 2 non-anti-spark male plugs. Effectively $15 for two AS connections, compared to $12 for 5 XT90S's. In the future I'll just stick to an XT90 loop key.

chuyskywalker said:

Installed an AS150 (anti-spark 150A) connector to do a slow-engage of the caps. Go figure the first one I used the built-in resistor was fried from the factory and I didn't test it. Well, I mean, I tested it the hard way with a surprising full 84v spark, which is great.

I'm...really disappointed in these AS150's. They are quite a bit more expensive than XT90-S, and for an "8 piece" kit you only get 2 actually anti-spark plugs; the rest is 4 female connectors and 2 non-anti-spark male plugs. Effectively $15 for two AS connections, compared to $12 for 5 XT90S's. In the future I'll just stick to an XT90 loop key.

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Whelp; killed the other one AND an XT90-S as well. 72v batteries do not care for the run-of-the-mill anti-spark solutions. So, I browsed the forum here, looked into alternative solutions and found this handy resistance pre-charge calculator, plugged in my controller's uF value and battery voltage, set the timer for 1 second and went shopping for a 75ohm resistor. Picked up a 2W one locally for a few bucks and made my own "xt90 antispark".



Tap that resistor plug into the male side till the controller beeps on (the 1 second time was very accurate) and then just quickly remove and plug in a bridge plug (just solid copper soldered between the pins; filled in top with hot glue). Works like a charm and I'm not in anyway worried about this failing.

Might reprint the box with a spot for XT90 surface mount receivers so I can just plug one in after the other. Though, I do sorta like some of the ideas around here about DPDT switches...

What did you use for "potting compound?"