A2B Metro restoration / modification - Fechter's first Ebike

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fechter   100 GW

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A2B Metro restoration / modification - Fechter's first Ebike

Post by fechter » Jun 02 2013 1:33am

Ironic as it may seem, after all these years, this is my first electric bicycle. Blazing Saddles, the largest bike rental company in San Francisco recently got some new A2B Metros, and by doing some consulting work for the owner, I was able to trade for a non-functioning old one that was in the 'junk' pile.
Before picture 2.jpg
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Really not too bad off, but flat tire, sheared off bolts stuck in the holes, assorted dents and scratches, corrosion and a totally messed up rear brake. Amazingly, the battery still seems to have decent capacity, so I've been riding around with it to at least experience the stock bike setup.
Before picture 1.jpg
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Overall, I'm very impressed with the quality of this bike and the $3k original price tag is not really outrageous for what you get. So this thread will be sort of a build log as I transform the A2B into something even better.

One of the first issues I dealt with was the rear shock. The stock unit had virtually NO damping, so if you hit a good bump, especially on a corner, the rear wheel would bounce and skip over to the side. In my junk box, I had an old shock that was a much nicer one, but had a spring rate of 650 lb/in versus the 1500 lb/in for the A2B. I tried swapping the springs, but the A2B spring was a little longer and impossible to install, well, at least easily... Eventually, I compressed the spring using my bench vice and wrapped it up with many strands of nylon cord while compressed. This allowed just enough clearance to install on the new shock. Once installed, I snipped the cords and 'boing' it returned to original length. New shock has adjustable compression and rebound damping. Very nice. Much improved handling on bumpy surfaces now. Looks cool too. Don't ask me where the shock came from or how to get one. It was traded many years ago and saw service on my Vego scooter.
DNM shock.jpg
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Another thing missing from the bike was a rear view mirror. I see they show one in the manual, but mine was missing. The levers have a 8mm threaded hole for a mirror, so I found one for $14 at the local motorcycle parts store. It's made by BikeMaster and seems to work well. Not too flimsy, not too heavy, and the big 4" round gives a decent rear view.
Rear View Mirror.jpg
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Another well known design flaw is the steering geometry. I think what it really needs is slightly more rake angle, but cutting the frame and welding it back is not something I'm about to do. What I came up with is a workaround for that. The basic idea is to flip the top half of the fork around backward so the front wheel has more trail. The stock configuration looks like this
Forks Before.jpg
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After flipping the fork around, it looks like this:
Forks After.jpg
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In order to do this, I had to separate the fork sliders from the stanchions. The top cap of the fork tubes have a 29mm hex head
Fork Cap.jpg
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I was thinking these things might be installed with Loctite and really take a lot of torque to get off. I found a 29mm socket at Sears, and spent some quality time with my bench grinder thinning out the wall enough to fit into the recess on the top of the fork.
Fork Cap Socket.jpg
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Grinding it down took a while, but it fits nicely. I used a piece of wood to block the forks from turning when I unscrewed the caps.
Fork 2x4.jpg
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When I went to unscrew the caps, I was almost disappointed in how easy they came out. I think you could get them out with a big needle nose pliers. Once the caps were off, I removed the springs and then the two lock nuts on the bottom of the fork sliders. Then, you need a really long 6mm Allen wrench to loosen the bolts. I used a 6mm Allen socket bit and a long wrench extension. These came out relatively easily as well.
Fork Allen Bolt.jpg
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Fork springs:
Fork Spring.jpg
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Once those are off, the sliders can come off (you need to disconnect the brake cable first).
Fork Sliders Off.jpg
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Once those are off, you then loosen the steering head clamp, spin the fork around backwards, and put everything back in reverse order. This is a good time to clean and re-lube everything inside the fork. I found quite a bit of water inside one leg, but it didn't seem to hurt anything. These are really top quality forks from looking at the insides. One thing they don't mention in the manual is the preload adjusters. Maybe they assume everybody know how they work. Anyway for the dummies out there (like me), if you turn the adjusters clockwise, it increases the tension on the springs. Be sure to turn both sides an equal amount. Here's how the adjusters look:
Fork preload adjusters.jpg
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Well, after a quick test ride, I can tell this really helps a lot. Before, it was difficult if not impossible to ride with one hand at 20 mph. Now, it's much more stable at speed and pulling a high-G corner doesn't scare the crap out of me anymore. Downside of the mod is the tire is now about 2cm closer to your toes and could possible make contact when maneuvering at low speed. I think it's well worth it. This will be important later on when I get to the speed mods :twisted:

Edit: after more test riding, I can say this mod absolutely fixes the handling issues. I have not had any problem with the tire hitting my toes. Handling is still nimble but now very stable and easy to take tight corners with. I think 30mph should be no problem now.

Next on the list is some lighting. I had a cheap blinking rear LED light that had the batteries leak inside and corroded the battery contacts. It was made to run on two alkaline batteries (3V). I tossed the batteries and battery contacts and soldered wires to the board and brought them out to a dc-dc converter. The converter is really a wall wart AC power cube for a Nintendo game. Output 5v. This thing is amazing. I start getting output at 12v and get full output around 24v. It's good up to rectified 240VAC (around 300VDC). Feeding 5V into the 3V LED blinker made it nice and bright, but it ran a bit hot. I placed a regular diode in series with the 5V to knock it down to 4.3V. This made it run a lot cooler but still really bright. I took it apart and removed the AC prongs and soldered wires on for the input.

One hitch is the blinky light has a pushbutton to turn off and change blinking modes. I don't want to have to press the button every time I want it on. I want it to come on as soon as power is applied. I removed the push button and soldered a 1uF capacitor across the switch contacts. This did the trick nicely and it automatically goes into the first mode when power is applied. If I 'flash' the power off/on, I can make it change modes. The little Nintendo adapter is small enough to fit inside the rear frame of the rack.
Rear light dc-dc.jpg
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For the headlight, I found a super cheap "9W" LED headlight on eBay for $15 shipped. This is one of those "DIY" versions that is not really rain proof or particularly well built. The built in dc-dc converter is rated for 12v - 85v and is easily removed by unscrewing the rear bracket.
light dc-dc.jpg
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The dc-dc unit is not water proof or sealed. This looks easy enough to fix. Out in the garage I had some old marine epoxy, probably 20 years old in a can. Still hardens with some fresh hardener.
light Epoxy can.jpg
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I pulled out the dc-dc unit and pried off the cheezy plastic cover over the box. I held it in the vise and poured in enough epoxy to completely submerge the circuit board. Afterward, I regretted not replacing the wires, but I can always splice them to the final wiring.
light dc-dc potting.jpg
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With the dc-dc potted, I think the rest of it can survive a bit of rain or washing. The lens assembly comes apart by unscrewing the ring on the front.
Light apart.jpg
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While apart, I added some heat transfer compound between the finned part of the heat sink and the plate holding the LEDs.
Since the heat sink was off, I decided to spray paint it flat black mainly for cosmetic reasons, but the aluminum was bare and would oxidize eventually if not coated. It's a bit tricky to get everything back together and you need to avoid leaving finger prints on the optics.

It runs noticeably cooler with the heat sink compound. Although advertised as a 9W light, it measures closer to 5W input when tested. Still, it seems bright enough for my purposes. I might get another one later and make a dual setup. It's not installed yet pending some wiring work.
Front light 1.jpg
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Finally got time to install the headlight... more wire stuffing and into the hairball again. I mounted it on the right side handlebar and installed a waterproof push-on/push-off switch that activated both headlight and tail light. I used a 3 conductor cable to feed switched power back to the tail light.
Headlight 1.jpg
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Headlight 2.jpg
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The tail end of the frame used to have some kind of plastic cap and a lock for the 2nd battery. These were gone when I got the bike, so I mounted the tail light to cover the hole:
Tail Light.jpg
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I had to drill a small hole in the frame to route the wire for the light.
Tail Light wire.jpg
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Since I frequently use the bike for short runs to the local grocery store, I scored a used rear A2B pannier frame. The frame is surprisingly light weight but seems sturdy enough. I combined this with an old Wald folding basket I had lying around. The basket folds flat when not in use and doesn't rattle too badly.
Rear Rack 1.jpg
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When I need to carry cargo, it just takes a second to fold the basket out and it can carry a standard sized paper grocery bag or probably two 6-packs of beer. I could get a second one, but I'm reserving the other side of the rack for a secondary battery.
Rear Rack 2.jpg
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"One test is worth a thousand opinions"

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fechter   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Jun 02 2013 1:34am

Here's a night shot with the lights on:
Headlight night shot 1.jpg
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One of the next items to upgrade was installing a Cycle Analyst. I had an old version 2.0 that was sitting around begging to be put to use. Mounting was a bit of a challenge, as I wanted to reserve some handlebar space for the lights. Ideally I wanted it right over the steering head. I ended up removing the stock mounting bracket and fabricating one from some scrap aluminum. I drilled and tapped holes in the sides of the steering head to attach the bracket.

CA bracket 1.jpg
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CA bracket 2.jpg
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CA installed.jpg
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This worked out well and is rock solid. It also protects the CA nicely in the event of a crash.
I used one of Justin's mini in-line shunt units installed in the line feeding power to the motor. The power used by the relay is not going through the CA, so I need to roughly take that into consideration.

Opening up the bottom of the frame compartment where all the wires live is a real worm-can. It took a while to get all the worms stuffed back in.
Hairball.jpg
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I used a piece of 14ga solid wire to fish the cable through the frame. This was pretty easy.
Fishing wire.jpg
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For the higher voltage experiments, I was worried about the relay coils overheating. I measured the coil resistance at 560 ohms. They are rated for 24v. For a 48v pack, I think adding some resistance in series with the coil might be a good idea. A small dc-dc converter would be better, but there is not much room to stuff one in the hairball. A 300 ohm 10W resistor in series with the coil should be good for my packs that top out around 58V.

My first long ride with the CA gave some interesting numbers. Typical current draw climbing a hill was right around 21A. The stock batteries sag quite a bit under load. I started out at 41.6v off the charger and the CA indicated the minimum voltage was 32.1v. Peak current (which I never saw) measured 29A. Cruising speed on flat ground was around 21mph. Maximum speed downhill was 25.8mph. If the downhill speed gets over something like 23mph, I start seeing regen. Maximum regen current was 9A. I averaged around 14.6W-hr/mile on my trip with moderate pedaling. The A-hr meter on the charger measured 6.9Ahr after recharging.

Ah, here are actual screen shots from the CA:
CA trip stats 1.jpg
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In preparation for attempting higher battery voltage experiments, I added a 250 ohm 10W resistor in series with the relay coil for the B battery.

I cut into the green wire on the key switch and put the resistor in series with it. This keeps the relay coil from possibly overheating if I give it full voltage. The relay coil is 560 ohms. It is rated for 24v. With the stock pack, it could sag to 30v when it's low, so I guess they gave the coil some extra juice. Being potted in epoxy probably helps the heat dissipation a bit.
Relay resistor.jpg
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Next, I cut off the stock connector and installed a pair of Andersons. There is an extra 4 conductor cable that runs parallel to the battery wires and I have no clue what it does. This is not shown in the factory service manual.
B Battery Connector.jpg
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I tried connecting the battery input to my bench power supply and slowly cranked up the voltage while watching the current. It was linear until I reached 58v, then the current started climbing quickly, like there's a zener diode in there. So the maximum input voltage for a stock controller is 58V.
CA with 57v.jpg
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I also noted the voltages for the SOC indicator in the hand grip.
Green threshold = 39.0V
yellow threshold = 36.6V
Red threshold = 32.9V

My 16s 5p A123 pack will be just under 58v hot off the charger, so should be OK.
Here's the pack.
A123 pack1.jpg
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I had a tool bag laying around that happened to be just the right size. I could even probably stuff the charger in there too if I wanted to.
A123 pack2.jpg
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I stuck it on the rear rack with some bungee cords. Weigh balance sucks there but it wasn't as bad as I thought it would be.
A123 pack installed.jpg
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Well, it sure is more fun at the higher voltage. Real weak off the line, but cruises around 26mph and hit around 30mph going down a slight hill. The A123 pack doesn't sag as much under load either, which makes it more fun. I ran the pack until it was done, then switched over to the frame pack. Bummer, it's soooo slow by comparison. Well, a lot better than pedaling. No smoke came out either, in fact, the motor seemed barely warm after running it hard. It will be more fun with an external controller for sure. Coming soon.
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Toorbough ULL-Zeveigh   10 MW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by Toorbough ULL-Zeveigh » Jun 06 2013 12:45am

well it's about time you joined the revolution. :D

nice work on the fork, never would have thought of doing it that way.
instead probably would have taken the lazy way out by rotating the handle bars 180 & live with the disc on the wrong/righthand side. :pancake:

how do you like the flat fender, is it actually functional or does water creep past the edges & you get splashed anyways?
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fechter   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Jun 06 2013 9:03am

If you just turn the handlebars around, you'd end up with the wheel about 2" closer to the pedals and you might have a clearance problem and it might add too much trail and mess up the handling. I tried the same thing on my Vego scooter, which had the same problem. It might be worth a try though... easy enough. It would also be necessary to unbolt the fender and reverse that along with rerouting the front brake cable.

I haven't tried riding in the rain yet. It doesn't rain much here during the summer months. I think the front fender will be OK. The rear fender has been bobbed and won't provide much protection. The rear fender stays have a tendency to break or bend and all of the rental bikes had the rear fender chopped off.
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spinningmagnets   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by spinningmagnets » Jun 06 2013 9:20am

For the new guys who want to add a pic-tutorial to share what they have learned about an upgrade to their project, there is a 20-pic limit to each post, and that's the reason for the starting the thread with several contiguous "reserved" posts. Better for the Original-Poster (OP) have too many reserved posts instead of too few.

Awesome thread fechter! I have always liked the A2B. Since the company doesn't seem to be growing very fast with such a well made product, I "think" it may have something to do with how the bike "looks like" a scooter more than a bicycle, leading to a fear amongst potential customers that they might be un-necessarily harassed by local traffic police...since the laws concerning bicycles and scooters are so different. Even if the judge always lets you off by dismissing the charges, its a hassle to go to court frequently.

This past year, European and Japanese companies have made a serious investment in pedelecs, so you must be "clown pedaling" to get any power, even if its been tweaked so that your legs are not contributing at all. Such a system would ensure you would never accidentally be seen zooming past traffic without pedaling.

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Re: A2B Metro restoration / modification - Fechter's first E

Post by Ypedal » Jun 06 2013 10:23am

awsome !!!...

when my A2B finally does fail, i'll be doing this exact same mod to the fork... any high-speed riding on a stock a2b would be sketchy as hell..

when you seperate the motor halves, please take pictures of your method of choice !!..

edit : and the details of gutting out the stock controller/re-wire to infineon controller :D
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j3tch1u   10 kW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by j3tch1u » Jun 06 2013 1:54pm

this sounds fun. i've always liked those A2B's and I thought they'd be a great base for enhancements. looking forward to seeing what you do on yours.

lol, i was just at the DNM factory yesterday to pick up their new triple-crown fork for testing (first batch).

i shouldn't bash, but i can't resist a good ribbing: DNM: either Does Not Move or is too DaMN heavy
fechter wrote:
DNM shock.jpg

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Re: A2B Metro restoration / modification - Fechter's first E

Post by binlagin » Jun 06 2013 10:21pm

Defiantly needs a controller upgrade!

I passed an A2B on my mountain bike yesterday w/ 2.3" tires under 100% leg power. Drafted him for 1 minute before I was bored of being held up! The guy was pedalling like a maniac too!
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fechter   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Jun 07 2013 12:07am

binlagin wrote:Defiantly needs a controller upgrade!
It's on the list. I have several to choose from. I'm going to torture test the stock controller for a while first. :twisted:
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Re: A2B Metro restoration / modification - Fechter's first E

Post by Degull » Jun 07 2013 3:27pm

I have been eyeing the local kijij and craiglist's for a broken A2B for over couple years now. Congrat's on a great score, I will be following this one!

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Re: A2B Metro restoration / modification - Fechter's first E

Post by edamame » Jun 22 2013 6:42pm

I have a hopped up 38 mph 72V A2B Metro and the fat Kenda tires that come stock are the reason for poor handling (after you replace the rear shock). As soon as I switched to Pirelli ML75 moped tires the handling improved immensely (tire size 2.5 x 16") . I would buy these moped tires and cut up the stock Kendas. The Kendas are dangerous at higher speed threshold cornering. Not even good as spares. The suspension works a lot better if you get rid of the stock tires. I have a RP-23 rear shock.
Last edited by edamame on Aug 25 2013 11:54am, edited 2 times in total.

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Jun 23 2013 1:00am

edamame wrote: I will look at switching my front fork around. edit: I just don't see an advantage of switching the fork around. It would reduce wheelbase and I cannot see where the steering angle would change.
I agree that a more round profile tire would be better for handling. I like the fat tire look though. I wish there was a better one that was still 3" wide.

Turning the fork around does shorten the wheelbase, but the main point is it will increase the amount of trail in the steering. Since it's not so easy to change the steering head angle, this is the only way to do it. Trail is the distance from the steering axis to the contact patch of the tire. Stock, there is essentially zero trail. The steering axis needs to be ahead of the contact patch by some amount. I think this is also referred to as caster. Without it, the steering is dangerously unstable.

With the stock setup and tires, I thought I was going to eat it the first time I tried to take a corner with some speed. Scared the crap out of me. Now, it feels more like my motorcycle. I can do a right turn at an intersection without slowing down first and it feels rock solid. With better tires, it would be even better I'm sure.

I think the stock tire profile causes the trail to decrease as you lean over more. A more round profile probably keeps it more constant.
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fechter   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Jul 14 2013 9:59am

I've been out riding more than working on the bike lately. One nice place I found within range is the local sewage treatment plant. This is one of the nicest sewage treatment plants I've ever seen. There is a section of the road where you're downwind of the main plant and the smell is pretty bad, but just pedal faster. Surrounding the plant is a series of wetland restoration ponds that stretch out to San Francisco bay.
Wetland trail 1.jpg
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Wetland trail 2.jpg
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Duck pond.jpg
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Power Line walkway.jpg
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They also have a huge solar panel farm that powers the plant. All I need are some jumper cables :twisted:
solar farm 2.jpg
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Solar farm 1.jpg
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The A2B does very nicely on the hard packed dirt roads.
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Re: A2B Metro restoration / modification - Fechter's first E

Post by john in dc » Aug 02 2013 12:17am

Very interesting project. Any other mods or updates to share?

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Aug 04 2013 1:20am

john in dc wrote:Very interesting project. Any other mods or updates to share?
I just added some updates to the first post.
Coming soon: Cycle Analyst install and experiments with higher voltages.

So far I'm very happy with the handling and rear suspension. I've done quite a bit of riding on dirt roads and trails and it handles that stuff fine. The only limitation I don't like is the maximum hill grade.

From my house, I can ride to China Camp State Park http://www.parks.ca.gov/?page_id=466 , where there are lots of bike trails and nice scenery (and smells better than the sewage treatment plant). This place seems to be a real magnet for lycras, most of whom truck their bikes on the back of a SUV to get there. So fun to pass them going up the hills.

Here a few pictures from China Camp State Park. San Francisco bay is in the background:
China Camp 1.jpg
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China Camp 2.jpg
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China Camp 3.jpg
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fechter   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Aug 09 2013 6:44pm

More ride pics:

Hold nose and ride fast past the sewage treatment plant, then to the duck pond
MP ride 1.jpg
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When there's nobody around, you can go full speed on the hard packed dirt roads
MP ride 2.jpg
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Nice shady spot to take a break: Where's the beer?
MP ride 3.jpg
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MP ride 4.jpg
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There's a trail that goes along the top of a berm for miles and ends at the edge of what used to be Hamilton Air Force Base. The old runway lights are still there but they're turning the runway back into marsh land. This is heading back; Mount Tam is the distant peak on the right.
MP ride 6.jpg
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Another shot of the solar panel farm. I really need to get some long jumper cables.
MP ride 7 solar farm.jpg
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fechter   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Aug 25 2013 10:02pm

Update in the long second post. I tested with a bench power supply and determined the maximum allowable voltage for the stock controller is 58 volts. Any more than that and the current starts to suddenly increase sharply. Smoke will soon follow for sure. Luckily this is just right for my 16s A123 pack. This would also be OK for Lipo up to 13s or even 14s if you charge to 4.15v/cell. Speed goes from about 20mph to about 26mph. Power consumption goes to about 25W-hr/mile.

Funny; above 20mph, pedaling is pretty useless so I 'ghost pedal' to throw the lycras off. They see two wheels, check, pedals moving, check, regular bike registers in their head and they usually don't notice how fast I'm going unless I pass them. Sometimes I ghost pedal really slow like I have a 500 tooth chainring. That must really confuse the hell out of them. :twisted:
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Re: A2B Metro restoration / modification - Fechter's first E

Post by Ypedal » Aug 26 2013 7:03am

i love pedaling backwards.... :P
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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Aug 27 2013 12:17am

Ypedal wrote:i love pedaling backwards.... :P
OK, I'll try that next time. I need a video camera to catch the look on their faces.
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Re: A2B Metro restoration / modification - Fechter's first E

Post by petedegan » Aug 28 2013 7:06pm

Nice mods fecher. I too have been running a a2b with a ping 48v 20ah battery strapped on the rear rack. I have put about 2000 mi on without a problem. But i agree, a controller upgrade is in order. The thermistor in my wheel overheats while climbing hills and i have spent much time at gas stations icing the motor down.

I have a spare motor that i opened up, (all the spokes need to be removed)that i plan to run sensorless. The a2b stock controler is anemic.

A couple things that i learned are superior about the a2b compared to most ebikes:


The big steel center stand. This in itself is almost worth the cost of a new a2b, (my other ebikes fall over daily. )

The riding position is comfortable, the bars are high, and the seat design is perfect for ebikes.

The spokes dont break

The rear rack that is low over the small 20" tire. Its nice its part of the frame too. Perfect for carrying a battery

The step thru frame is nice for anyone to get on and ride.

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Aug 28 2013 7:22pm

petedegan wrote: I have a spare motor that i opened up, (all the spokes need to be removed)that i plan to run sensorless.
I'm planning to do that soon. How did you get the halves of the motor apart?
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fechter   100 GW

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Sep 04 2013 12:54pm

Well, a few minor failures;
I was cruising around on the A123 pack when it suddenly lost power and died. I switched over to the frame pack and it ran OK (this is a very handy feature as you can switch over on the fly). After tracing wires, I found the trailer hitch connector down in the hairball had a bad connection. I hate those connectors. I took it apart and squeezed the female parts to make them tighter and reconnected it. All good after that. I will eventually replace those connectors with something better.

The bike had developed a strange screeching/clicking sound in the rear that sounded like the stator rubbing against the magnets. It would come and go depending on motor heat and which way I was leaning. I discovered that several of the spokes had become loose and I think this was causing the motor housing to get out of round and rub. After torquing the spokes tight, the noise went away. When I take it apart, I think I will be able to see where it was rubbing.

The kick stand eventually loosened up despite having it torqued very tightly to begin with. This time I applied Loctite to the entire square surface where it mates with the frame, as well as the bolt threads. I'll see how long this lasts.

I've done quite a few rides at 48v with the A123 pack and the stock controller seems OK with it. Slow off the line, but does 26-27mph on flat ground. I'd really like to get a bigger chain ring for the front so I can actually assist at that speed.

I was travelling on a freshly paved section of bike trail that runs along the freeway and while taking a sharp corner, the front wheel lost traction when I passed over the center line paint. I almost dumped it, but I guess my old motocross instincts saved me as I stomped my foot down on the low side and got it to regain traction before going completely down. Fresh pavement is really nice and smooth though. On one of the long uphill sections I came up on a lycra that was right in the middle of the path blocking me. A couple of dings on my bell and he moved over and I passed him like he was standing still. After reaching the end of the bike path, I turned around and headed back. When I came across the same guy going the other way, he did a real head-turn when I passed by him.
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Re: A2B Metro restoration / modification - Fechter's first E

Post by wymjymn » Sep 08 2013 7:16am

fletch,
I posted this yesterday re: chainring
http://endless-sphere.com/forums/viewto ... &start=300

as to the center stand, it will not remain tight unless you shim the bolt to allow for greater torque on the nut. This is my experience and that of others.

my stock controller 'died'...using a lynn unit with the sensors works well for me. Being able to accelerate from a dead stop is nice.

wj

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Re: A2B Metro restoration / modification - Fechter's first E

Post by wymjymn » Sep 08 2013 7:48am

also, the single rear torque arm is not up to higher torque loads
I got a pair of SS units from edamame

wj

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Re: A2B Metro restoration / modification - Fechter's first E

Post by fechter » Sep 08 2013 10:20am

wymjymn wrote:fletch,
I posted this yesterday re: chainring
http://endless-sphere.com/forums/viewto ... &start=300

as to the center stand, it will not remain tight unless you shim the bolt to allow for greater torque on the nut. This is my experience and that of others.

wj
Thanks for that. Good tips.
"One test is worth a thousand opinions"

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