There are two types of electric conversions for an electric cargo bike…one is fast and cheap, the other is more labor intensive and expensive but it has better performance. If you can afford it, a mid-drive cargo bike is the way to go.

#1  hub motor conversion. This is the easiest, and cheapest way to go. Most electric cargo bikes consist of a hub motor. There is plenty of articles on this site about hub motor conversions but read our hub or not to hub story first if you are trying to decide between a hub motor or a mid-drive. There is much written on electricbike.com about various hub motor kits and conversions.

#2 Mid-Drive. The cargo bike begs for a mid-drive, especially if you live in a hilly region. Mid-drives are the perfect solution when your carrying weight or traversing hills because you use the bicycle pedal gears as the motor gear system. Now you have granny gears for climbing with only the motor!  Read our story on mid drives here.

The Cargo E-bike lends itself especially well for mid-drive conversion. Because of its extended frame, there is usually a space in between the crank set and the rear wheel to optimally place a chain drive system. Many builders have built up systems themselves, but there are several kits on the market to make this task easier.

 

Urban Commuter Yubo Mundo Conversion

The Urban Commuter Store sells a nice bolt-on kit to convert a Yubo Mundo bike to an efficient mid-drive bike. This is the easiest and among the most affordable ways to have a mid-drive cargo electric bike since both the drive sytem and the Yubo Mundo bike are affordable.

 

 

The kit costs $1500, which includes the custom mounting bracket, a geared MAC motor, controller, and Cycle Analyst…but does not include a battery. This is actually a great price for what you are getting. With this kit and an affordable Mundo frame you have a very effective cargo ebike for under $3,000 which is very cheap for a mid-drive bike.  The Yubo Mundo bike can be bought brand new for under $1000. Factor in $500 for a nice and big Ping LiFePO4 battery and you have yourself a very good bike for around $3000.  Consider other commercially available mid-drives, the $13,000 Optibike, the $7000 Hanebrink and you can see how this E-bike is a great price…For this money you get a bike that is better balanced, more efficient, more dependable and a better extreme climber than a traditional hub motor bike. If I were to buy a cargo E-bike this is the combination I would buy. I have talked to the Urban Express owner and this kit is still indeed in production, and they are taking orders….I am tempted :).

 

The Stoke Monkey

Like the Urban Commuter, the Stoke Monkey uses a hub motor conveniently located in the space between the seat tube and the rear tire. One characteristic of the Stoke Monkey is that you need to pedal when applying power because the motor does not freewheel. The Stoke Monkey is no longer in production by the company who invented it Clever Cycles, but many people are building there own “Stoke Monkey” and several small shops are building the bracket needed to affix the hub motor to the cargo bike frame. If people expressed enough interest in buying a Stoke Monkey, maybe Clever Cycles will do another production run of this great device.
Ecospeed
The EcoSpeed is a pricey mid-drive that some people have used on their cargo electric bikes. It doesn’t lend itself especially well because it mounts to the downtube, and does not take advantage of the space between the seat stay and the rear tire. However many cargo electric bike DIY builders have opted for this system. They do offer a complete system including batteries which will make converting your cargo electric bike to a mid-drive a finger snap (at a financial cost).
However the “Long-John” styled cargo bike with the Load up front  lends itself very well to the Ecospeed.
Here is an example of an EcoSpeed in action on a cargo electric bike:
Splendid Cycles in Oregon has done some excellent Eco-speed conversions using the very fine (and expensive) Long-John styled Cargo Bike from Bullitt. Here is one of my favorite examples. This electric bike carries a Keg of beer. Excellent for impromptu parties on the road: