Electric Bikes - Local Entrepreneur's Meeting

My electric bike has been a great conversation starter, but still I was surprised to be stopped on the sidewalk and invited me to this month's nocoentre.net entrepreneur's meeting. I later learned that the meeting's focus was electric bikes, so I signed up and showed up at 5:45 this evening, not really knowing what to expect.

Presentations ranged from a local business struggling to establish a motor assist business for bikes, to a startup looking for angel funding to setup up pilot projects for wide scale automated EV rental solutions aimed at first/last mile transportation needs.

Local businesses are converting junked motorcycles to electric power, selling books on e-bike and e-motorcycle building, and building electric bikes (Optibike) and scooters (Electro-Ride).

I'd like to help the "motorize your cycle" shop. They currently sell friction drive systems (gas and very low power electric), and are looking to expand into hub motors. They need a system that is simple to install and use, reliable, and moderately priced. Bionx comes to mind because they offer complete solutions, but there have to be other options. I know about hubs from BMC, Crystalyte, and others, but they need a complete system. The store is willing to source parts from different suppliers if they will work well together for customers who may not really understand what they are doing. What would you recommend?

I had an opportunity to chat with a guy who works for the Boulder based battery company that supplies battery systems to Optibike. He was very proud of the Optibike system, which uses Li-ion (cobalt) batteries that are purposely undercharged (to 90% capacity) to extend their lifespan (to be fair to customers, the nominally 25Ah packs are sold as 20Ah batteries).

I also asked about the use of Li-poly cells, a topic that came up in another thread here recently. Optibike started out using Li-poly batteries, and had something like a 50% return rate due to failure or poor performance. Li-poly cells are apparently very sensitive to the conditions the experience in their package as they expand and heat up with use. I left with the distinct impression that these are a bad choice for ebikes.

Some would say the same thing about lithium cobalt, really, which are the batteries known for exploding inside people's laptops :)

It all depends on whether you source reliable batteries or not, in the end. There are several variations on lithium polymer batteries all successfully being used in electric vehicle applications. Sony and Sanyo make a very nice chemistry which is a blend of cobalt and manganese together. making a hybrid polymer. The nicest pick in lithium seems to be LiFePO4 (lithium phosphate) at the moment, as these batteries are very reliable and have an extremely long service life compared to other lithium offerings.

There aren't many manufacturers who solidly sell their electric bike kits with batteries. BionX and eZee do, but its not a great trait. Because of it, with eZee the batteries come in an annoying plastic case, and BionX is worse. Particularily, BionX uses all proprietary components including their battery packs which are very costly and no better performers than any other. I like the BionX kit for its polish, but not for its closed system and high battery costs. You can't easily tailor the system to meet needs, its all or nothing.

I would just reccommend BMC and Crystalyte, really. They only thing that either of them need to be complete is a battery pack. Both are reliable products, BMC is a very good performer and Crystalyte is an extremely open ended system that allows for a lot of customization and easy replacement of parts. Source some reliable battery packs in a few different configurations, and you can offer complete kits to meet a variety of needs.

I agree with Abneycat. It is better to have non-propietary battery packs because the technology is changing rapidly. A good thing would be to have a couple of choices with all the same electrical connectors so they can be interchanged easily. There are a lot of different connectors out there and it drives me nuts when I am working on a number of different systems.
I am looking at a hill climbing/cargo motor, a fast (unless legal is a problem) system and a recumbent system. I am doing something like this in my small hilly town. I buy some system and try it out and then help others. I am waiting to get one of the new '600 watt' geared hub motors from BMC for the hills. At 9 lbs it seems like my dream come true. I need to haul at least 200 lb loads up 12% grades. The recumbent bikes are easy to put in an inline motor which uses the bike gears so the hills are not a concern. I use both Ecospeed which I easily hit 30mph and can haul big trailer loads and the Electroportal motors for just normal grocery type loads.
The battery I use are sealed lead acid for people just starting out. These will last about a year and by then the person will know whether or not they use the bike enough to spend some more up front money for LiFePO batteries.
Let us know what you come up with.

A good thing would be to have a couple of [battery] choices with all the same electrical connectors so they can be interchanged easily. There are a lot of different connectors out there and it drives me nuts when I am working on a number of different systems.

What connectors do you like? I am familiar with the popular connectors used for RC models (I like using Anderson Powerpoles (http://www.andersonpower.com/products/singlepole-connectors.html)), but I don't know whether any of these are sufficiently weather and UV resistant for electric bicycle use.

I have a pretty good grasp of the various battery chemistries available, but don't know what to recommend regarding specificy battery solutions (battery with management system if Li, charger, package). I have some ideas about what I might choose for my own use, but a complete, professional solutions are harder to find.


I am waiting to get one of the new '600 watt' geared hub motors from BMC for the hills. At 9 lbs it seems like my dream come true.
It is still a fixed gear, but otherwise looks quite nice. The recumbent mid drive options are extremely attractive, but I think conventional bikes are the place to focus for a business looking to make sales today (in an environment where many customers have DUIs or lost their driver's license for other reasons).

Anderson connectors are a common choice for electric bicycles.

There aren't many variable ratio motors out there for electric bicycles. There are fairly decent options, but all with higher installation complexity and often with additional complications. I have yet to see a good electric frame mount kit for a regular bicycle that had no special installation quirks and allowed the use of a double or triple crank. Most of the frame mount kits make for good electric motors, but bad bicycles. Its fine if you don't mind installing a proprietary crank system and dealing with reduced gear ranges and such, but I personally find the geared hub motor to be a better happy medium.

Yes, the only inline motor that I have liked is on recumbents. Of course, if people really did research the possibilities, they might end up with an electric recumbent. You sit down in comfort, can use a windscreen or even more fairings and once it is electric it goes up hills great. But, most people will just look at bikes as toys or electric motorcycles. In WA state, you can legally drink and bicycle. Maybe the state should advertise that in liquor stores.