Saturday, January 12, 2008

E-Bikes

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?

8 comments:

Ted Diamond said...

I've taken a course on oxyacetelene welding, and am scheduled to take a 2-week course this spring on frame-building (brazing), with a 2-day chaser on TIG-welding. My longer-term plan (Carol, stop reading here...) is to invest in a TIG-welding rig and get sustained practice on frame welding.

Your idea is very exciting to me, Nic.

Nic Pottier said...

Sweet!

I dont even think TIG welding rigs are very expensive anymore.

Let me know after you take the class and let's put our heads together and build something cool!

vaughn said...

http://cleverchimp.com/products/stokemonkey/

Hey Nic - here's a productized version of about what you're describing. I've seen these around town in Portland, and even one hooked up to a cargo bike (the same guy who started Clever Chimp is part owner of Clever Cycles where I bought my cargo bike - he has this motor on his personal cargo bike). the power output is pretty incredible. I saw this guy carrying his wife and 4 year old in the front of his cargo bike up a hill I try to avoid when I'm on my road bike - and quickly too. I think it takes more skill than it looks like to operate a bike with a motor on it, since that's not what bikes were necessarily designed to do; but I agree that it would bring a lot more people into the fold if this technology was common and affordable.

Nic Pottier said...

Very cool, I think I saw this at some time, maybe I'm subconsciously stealing it. :)

Still seems like a really heavy system, and I don't like the motor driving the pedals, that sounds pretty crazy, almost like a fixie but with a lot more power behind those turning pedals.

I think the goal would be to get a road bike together that is < 30 lbs. I think you accomplish that via limiting the range to ~15 miles, using very few gears, and LiIon batteries.

cya said...

I think this is the right time for some great riding e-bikes. We are in process of importing such, built to satisfy design criteria we felt important. Light, strong, rigid frame, using new magnesium alloys. 7 speed internal Shimano gearing, latest battery technology. Our Seattle based company will start selling these electric bikes to select dealers. see www.gecobike.com for details. Curt

cya said...

I think this is the right time for some great riding e-bikes. We are in process of importing such, built to satisfy design criteria we felt important. Light, strong, rigid frame, using new magnesium alloys. 7 speed internal Shimano gearing, latest battery technology. Our Seattle based company will start selling these electric bikes to select dealers. see www.gecobike.com for details. Curt

electric bikes said...

your ebike looks wonderful!

Phil Evans said...

I've seen a fella in W Sea who bolted a gear to the disc brake tabs of the rear wheel of a MTB (and used cantis on that wheel) and had a chain running up to the rear rack which held battery & motor. Went like stink.

I can solder, albeit poorly at times. Can I get in on this?