Electric conversion of a bakfiets cargo bike and preaching to the unconverted
Posted on May 05 2015
Two years after our blog post about pros and cons of electric conversions vs buying an all out electric bicycle, converting bicycles to electric continues to fascinate a certain segment of the public.
The topic came up first question in the first part of Bicycle Network Australia's e-bike buyer's guide discussion. I've pasted the responses from the panel of experts (our response is last) below. There seemed to be a general view that while a converted bike may not have all the features you need in an electric bicycle, it has the advantage of being a cheap option to get started. It's important to realise that converting your bike isn't cheap unless you use cheap parts and then you've just got a bad product You could have sold your used bicycle if you didn't think you needed it and remember that used converted bicycles don't resell for much and the battery for your conversion kit will have compatibility issues if you try to cut your losses and go for a complete e-bike but keep some of the parts.
Ironically, though being known to be generally pessimistic about conversion kits, we actually take the view that a conversion kit serves the exact opposite purpose, it's main function is for a project where value for money is not the priority and the budget exists for a great bike, a quality conversion kit, accessories required to make it all work together and to take advantage of the electric power (eg e-bike lights) and the labour of an experienced mechanic to make sure the vehicle is safe and incompatibilities are solved. Whether you're talking e-bike, conversion or normal bicycle, why settle for anything less than a safe bike that's a pleasure to ride?
We recently converted a Dutch cargo bike or 'bakfiets' to electric using the eZee kit. The job fit all of our criteria for appropriate use of an electric kit: the factory fit option did not provide a throttle which the customer required, nor high powered lights running off the battery, the warranty was shorter, the voltage lower, parts not in stock in our shop and the battery mounting was not ideal. In short, by using a conversion kit we were able to make a better final product, even if it did cost more.
The final product shown above carrying a Brompton folding bicycle (how else do you come pick up your new bike?)
We made use of Grintech's (ebikes.ca) new CNC machined mount for eZee flat pack batteries. The battery pictured is secure, locked and unlockable. It's mounted at the bicycles centre of gravity and low down, ideal for good handling. It doesn't interfere with the rear rack and achieves a subtle conversion. It's under the bench where kids usually sit so it's out of harms way from bags or being stepped on as well.
It would be difficult to get the charging cable into the charging port like this. So we extended the charging port away from the battery and through the bakfiets wooden wall. The other cable is going to the controllor, which is mounted below the box.
This is the external charging port. Simply plug the bike in to charge up, using the standard eZee 36V battery charger. The bolt on the top right is holding the CNC battery mount.
The eZee kit supports both pedal assist and throttle control. It took some work but we fit the pedal sensor inside the fully enclosed chainguard
The 1000 lumen super bright light, the 'cycle lumenator' from Grintech. This clever light can use input voltages ranging from 15V-100V! Click to see all our e-bike lighting options. Access to bright lights that run for the entire length of your ride that you don't need to recharge (obviously you have to recharge your main battery as normal) is one of the most underrated benefits of an electric bicycle. On commuter bicycles we commonly spend up to $400 on a hub dynamo powered system to achieve the same thing.
By mounting our battery in the box we were able to use the original rear rack. Being a Dutch bicycle, it means that it's a high quality rear rack that fits the frame perfectly and comes with luggage straps. That's our Spanninga 36V rear light mounted to the rack, which is powered by the main e-bike battery.