How to make the A2B Metro go faster?

[mobman]

Hello all....I have had my A2b Metro for about 4 months now, I bought it used so its already out of warranty.

I am looking to make it go faster around 30 mph range unassisted (yes I know it has be off-road, its not a scooter, it doesn't qualify as a bicycle if we go over 20, motor overheats and blows up or melts wires, I have to be careful, I have to be a perfect law abiding citizen and I am crazy for making a suggestion like this yada-yada - I get it).

I am still interested in making it go faster so what can be done about it?

Lets start with the cheap mods first and work our way up.

Thanks.

 

[amigafan2003]

Simple solution, get a higher voltage battery. If you're currently on 36v try 48v - that'll increase the speed by 25%. The controller "should" be able to take 48v as most 36v controllers have 63v caps. Bear in mind the watts to the motor will also go up as well.

If you want to push it even further then you could try 15s lipo (63v hot off the cahrger) or 16s lifepo4 - 57.6v hot off the charger - both will increase top speed by 54% or 45% respectively.

Obviously, if your controller doesn't have 63v caps then you'll kill the controller with the above voltages - but then you have an excuse to but a new controller

The motor should be able to handle the wattage but have a think about torque arms.

 

[Russell]

Do keep in mind the A2B controller is INSIDE the motor so if it's blown up the motor needs to be disassembled. To disassemble the A2B motor the spokes need to be removed so exercise caution when upping the battery voltage. 48V may not be a problem and should yield about 26 mph but I'd think twice about 15S :| If the present 36V battery is in good shape you could simply add a booster battery to get you to 48V.

Ypedal has the best review of the A2B Metro on this site and he suggests opening the motor, removing the controller and using an external one. If you want a reliable 30MPH that's probably what you need to do.

http://endless-sphere.com/forums/viewtopic.php?f=4&t=16742&p=548528&hilit=a2b+metro#p548528

If it were me and I wanted to take the easy route to a badass Metro I'd just sell the A2B rear motor/wheel and replace it with a new Crystalyte HS motor/wheel kit from ebikes.ca...with the 40A controller upgrade of course, then load up on LiPo

-R

 

[dogman dan]

Yeah, pretty much the best solution would be a start over. 48v may not wreck the controller, but if you increase watts too much and then run it 30 miles nonstop, you could be getting into melting stuff territory.

As always, temp sensors on the motor are a great idea if you are going to push stuff.

The other thing to seriously consider, is that if you are starting over anyway, different motor, contoller, and obviously a lot more battery than the A2B comes with, why not just build a second, much faster bike?

Get a decent used hardtail mtb, and put a dd motor on it. Something like the Clyte, or a muxus/ 9 continent type. A cheap muxus will do 27 mph on a cheap 48v 20 amp controller. Fast but not quite so fast that you can't slow down in time for a cop. It would do a 30 mile trip at full speed with enough battery without melting at that amps.

 

[friedwires]

Dont retire it, rewire it http://endless-sphere.com/forums/viewtopic.php?f=10&t=20102

 

[Ypedal]

Agreed.

I'm currently running an extra few cells in series wiht the A battery to bump up the top speed a bit, but regardless, the A2B controller has a soft start controller that sucks when you want power off the line...

Replace the stock tires, install a better rear shock, remove rear spokes, seperate the motor halves ( and they are press fitted, not screwed on !!!!... you risk cracking the motor case if you do it wrong... it's been done by regular people but UM has a special die that fits into a press to do this properly....

bottom line, as said above, eithe rreplace the rear wheel with a different hub motor using external controller for a proper 48v ~ 72v setup, or put the hours into modding the parts you got.. either way there is no easy path to 30mph on the metro.

possible, yes
easy, no.

 

[Suffixated]

Here's another possible solution: The newer model 2011 A2B Metro has an external controller from the motor. Buy a replacement motor from Ultramotor and a separate controller to swap in. You might as well see if you can get an A2B Excel 800w motor while youre at it.

I'm somewhat of a luddite when it comes to this stuff so that would be my workaround.
http://a2b.ultramotor.com/en_ca/excel