The ute post, Ted's internally geared hub post, and just general interest in the subject has me just rearing to build an e-bike for kicks.
The technology has gotten to the point where you can make a pretty compelling bike. You can buy awesome LiIon batteries that can easily power a bike and will last thousands of recharges. Batteries got a whole lot better in the past few years thanks to A123, which is the suppler for the Tesla super exotic electric car. Consumers can't buy the individual cells, but they can buy 36 volt packs from Dewalt along with chargers etc..
One guy (in Seattle no less) built what he calls is the 'ultimate' e-bike using this stuff (see below), but I don't really agree with some of his choices.
1) I don't think a full suspension bike is the right choice. It's heavy (especially a $150 full suspension bike, yikes!) and just unneeded. A front fork might be nice to have, but a rigid rear end makes much more sense.
2) I think building a bike like this on a ute frame would be cool. More room for the batteries and controller and more cargo space with your added horsepower.
3) I'm not sure I like the hub motor. Seems heavy, more rotating mass too. Would be neat to do something that was chain driven on both sides, one side via the motor, the other via the pedals.
4) How about just having one speed and using the motor to flatten the hills? Again, less weight, more simplicity.
In the end I just think it would be really neat to build a steel framed city e-bike using some of this tech. Make it as light as possible by removing as many components as possible and having realistic goals. Two battery packs would get you a 10 mile range of serious assist and you could probably cruise at around 20 MPH even up the hills, all with one hour recharges.
I think a really neat business idea in general would be to try to build bikes such as this. Come up with a decent steel frame that allows for cargo capability. Hire at risk youth and train them to weld / paint / assemble the bikes. Sell online for profit! Ideally you could get to a point where you could get supplies of the A123 batteries and build a more streamlined pack and recharger.
The goal being not to build the highest performing bikes in the industry, but functional, maybe even stylish (cruiser frame anyone?) that would be accessible to anyone, even in Seattle.
Yes, sweating is a-ok, but even I get a bit tired on the hills sometimes, and let's face it, for a lot of people a 10 mile commute every day is just too much. Making it easier, even just flattening our Seattle hills might get many more people on bikes.
Anybody know how to weld?