Bicycle Mechanics - A2B UltraMotor Modification Help?

I just purchase and A2B Metro http://ultramotor.com/us/product/a2b_metro/technical_specification and have been really enjoying it! There are a few things I would like to change. I have been ridding for 20 years but I am an Bike Mod newbie so please do not assume that I know anything... :-)


1. Shocks
2. Cranks

1. I would like to be able to ride someone on the back of the bike! When I do this now the shock sags to the bottom and the bike will not accelerate reliably. I tried it with the stock shock as well 2006 Manitou RADIUM RL 152 x 32 C8X40 Rear Air Shock http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... c9E9A%253D . The performance on the Manitou's shock is even worse. Do they make shocks that have a lock out? The problem with Air shocks that lock out is that they are a "soft lock" and still compress if pressed too hard? What do 300lbs+ people do for full suspension rides?

2. I find that the stock cranks do not provide enough torque. I found someone else who did a mod to this bike here http://endless-sphere.com/forums/viewtopic.php?f=4&t=20991&start=15 The cranks he bought look solid If anyone knows the name and/or has a link to where you an get them it would be much appreciated. Would any 50T crank work or do I need to look for something special?


Thanks for your help it is much appreciated!

I just purchase and A2B Metro http://ultramotor.com/us/product/a2b_metro/technical_specification and have been really enjoying it!

That's an electric bike, this forum deals mainly(if not exclusively) with human powered bikes. You may have better luck elsewhere.


1. I would like to be able to ride someone on the back of the bike!.. When I do this now the shock sags to the bottom
Well, take a shock only intended to be used on a one-rider bike and stick two riders on it and that is hardly a surprising outcome. If it is an air shock you can try pumping it harder. Don't blame me if you blow the seals though.


I would like to be able to ride someone on the back of the bike! When I do this now ..the bike will not accelerate reliably.

It hasn't got the power, end of story. Maybe try pedalling simultaneously to help the motor out.


What do 300lbs+ people do for full suspension rides?

Dream perhaps? Not many 300 lbs cyclists out there. Or they bite the bullet and buy a scooter instead. Or stay on rigid frames.


I find that the stock cranks do not provide enough torque.

Er, what?
Either the gearing can be too low, in which case you'll be spinning your legs like crazy w/o feeling any resistance. Solution: get a bigger chainring or a smaller (set of) sprocket(s). Spinning like crazy means more than 100 turns/minute. If you're below that, do some cadence training instead.

Or the gearing can be too high, in which case all gears will feel too heavy. Solution: Get a smaller chainwheel or a bigger (set of) sprocket(s).

Sometimes the chainring can be replaced separately from the crank, sometimes they have to be replaced together. The ridiculously named "specification" doesn't tell which.

Hi Shurafa,

Nice Wheels! I am looking seriously at the A2B Velociti but can only find one review. I think generally the motors and batteries are the same.
How many miles can you go with some light pedalling?

Hi Shurafa,

Nice Wheels! I am looking seriously at the A2B Velociti but can only find one review. I think generally the motors and batteries are the same.
How many miles can you go with some light pedalling?

I get about 12 miles off the main battery. I ended up getting a second battery which brings the total to 24.

Thats a long way from the 20 MPH unassisted that they advertise. I ended up getting the Velociti, super quality bike but disappointed with the 20 KM or so I think I am getting on one charge.