MIT GreenWheel: Simply an electric bicycle revolution
One definition of the word elegant is "to be gracefully concise and simple." In the future, the dictionary just might include the GreenWheel as a product that illustrates this principle perfectly. From the MIT Smartcities team that gave us the stackable cars concept and the RoboScooter (still a go), comes a wheel that can turn an ordinary bicycle into a very desirable electric one in an easy, cost effective manner. Enclosing a motor, A123 Systems batteries and a generator into a small aluminum pancake hub, the GreenWheel can give you up to 25 miles of propulsion, or much more if you don't mind pedaling. Unlike conversions kits from the past, it forgoes running wires the length of your bike by incorporating the magic of bluetooth to control the twist-throttle.
Over a dozen different configurations of the GreenWheel are scheduled to be tried and tested by a variety of cyclists this spring. Once the the team analyzes their feedback, an ultimate configuration of power, speed and cost will be settled on and mass production will get under way. With an estimated cost of "several hundred dollars," they better plan on making a lot of them since not only are they a wonderful "solution" for several cities and ridesharing programs already showing interest, but in a world-economy that can't afford to buy cars the way they used to, the GreenWheel should have a bright future.
[Source: MSNBC]
Reader Comments (Page 1 of 2)
Stan Wellaway 7:19PM (2/19/2009)
Ooh, I do like that. Very neat and sweet. Deserves to win a design award.
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why not the LS2LS7? 8:23PM (2/19/2009)
Bluetooth? That means the speed controller on the front has to have another battery in it to power itself. That seems dumb. Sometimes a wire is the right thing for the job.
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Chris M 9:04PM (2/19/2009)
Bluetooth was designed for reliable very low power communications, but you're right, a simple wired controller would work just as well and would probably be cheaper.
I'd wonder about the limited number of batteries that could be fit into that hub, and the connection for recharging doesn't show up in that photo. A more conventional frame mounted battery pack and hub motor might not look as neat, but it would be more practical.
Eric 8:37PM (2/19/2009)
Now apply the concept (at least the motor part) to an electric motorcycle with something like a HyPa drive motor. 160 hp motorcycle! Electric! No chain or transmission! More room for batteries under the fairings!
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Toshi 9:44PM (2/19/2009)
I don't see the point. Keeping batteries out of the hub leaves much more room for them. I'd bet this wheel will have less than 250 Wh of capacity. Claiming 25 miles of range on that is stretching the truth, or assuming a 10 kph constant speed or other nonsense.
For reference, here is my electric bicycle, with those old-fashioned wires. The wires were never the problem... I run 576 Wh worth of LiFePO4 battery, for the record.
http://endless-sphere.com/forums/viewtopic.php?f=3&t=3999
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Herm 12:50AM (2/20/2009)
from the picture it appears they are using about 16 A123 cells, total 110Wh capacity.. I dont see how to get 25 mile range out of that unless it's just a power assist.
John Rowell 10:50PM (2/21/2009)
@Toshi, I checked out your bike, really liking the small lithium battery pack - but why is it that you don't use the Crystalyte rear motors that have freewheels? What was the problem you had with freewheels? The reason I ask is, I own one with a freewheel (and I sell them too - http://www.discountpv.com/electric_transportation/c408r-36sla.htm ) - and haven't had any problems.
Toshi 11:53PM (2/21/2009)
I used to run a freewheel on my mountain bike. This was around 1992. Modern Shimano/SRAM/Campy cassettes with their shaped teeth are much better than freewheels. Furthermore, you avoid all the problems with spacing, wheel dish, and chainstay clearance when you stick with a front wheel.
My battery pack isn't actually small -- it's in the green pannier on the far side of the bike in the photo, and is about 18 lbs of LiFePO4. The duct taped thing on the downtube is the controller.
Hans 10:11PM (2/19/2009)
I just don't see the point, what's wrong with just pedaling your bicycle?
Electric vehicles that can go 60mph for 100 miles and carry a family of 4, now that seems relevant.
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Snowdog 12:28PM (2/20/2009)
The point is a lot of time when you are commuting, you don't want to arrive soaked in sweat. So as a transportation device an electric bike makes a lot of sense (at least to me).
Going to movies with friends. Battery power over, then pedal home if you feel like it.
Tim 8:20AM (2/20/2009)
Another brilliant idea from the folks at MIT.
Keep it under $500.00 and I'll take 2, please.
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Jordan 2:19PM (2/20/2009)
Umm hub motors have been around for years, just google "electric bicycle"
What is so revolutionary about this?
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BoneHeadOtto 5:41PM (2/20/2009)
I think the revolution is not that it is a hub motor but it seems to me that it does not have a throttle but instead assists your pedaling, using your pedaling as the throttle. If it uses no wireless communication and has not wires then it must be using your pedaling input as throttle
jeremiah 2:25PM (4/23/2009)
Think about adding the green wheel to folding bikes like the Dahon. Someone could easily have a 40 mile commuter that could fit under their desk at work (that would be indirect competition with the chevy volt). How I believe that this is revolutionary, how it could add to the the combination of engineering and modern electronics. Now you could use your blue tooth and gps on your phone to record mileage, wheel revolutions, track your heartbeat compared to your output on the bike, to find inefficiencies in your riding. Can the current electric bikes do that?
Doug Goncz 8:55PM (2/20/2009)
I'm not impressed, but am greatly challenged by the design idea since I"m working on something in that area.
What do you do when the batteries go dead? What's the drag?
I like the Bluetooth controller. What happens when someone hacks your throttle? Go zooming off into traffic? LOL. There should be a dual option for a wire.
The article reads "A123 Systems batteries". Is that a cell type or a manufacturer's corporate name?
There should be a front wheel option for 2WD on difficult terrain.
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Domenick Yoney 10:43AM (2/20/2009)
A123 Systems is the name of the battery manufacturer. They batteries are expected to last around 40,000 miles. They are recharged by pedaling or by being plugged in.
The source article says that "front, rear or both wheel can be equipped with a GreenWheel"
MT 10:57AM (2/20/2009)
The design has some really nice elements. The huge advantage to the batteries packaged in the motor is no need for batteries hanging on the frame or taking up rack space. Combine that with the wireless throttle and there's no issue with wire length issues for different size bikes and having to stash excess wire somewhere or cut and solder or reconnectorize multi-conductor wire.
As some have said though, those design decisions do come at a cost. I'd keep the in-motor batteries but would like to see a jack/power point that would allow an additional battery pack to be paralleled with the internal one. That would give you the option of a compact, neat, and light unit if you had short trip requirements, but the ability to add more batteries for more range if needed. Also, an optional wired controller, maybe with RJ-11 or RJ-45 connector at one end of the wire, would make it easy to cut the wire to length and crimp on a standard connector that is readily available.
Finally, those who ask why not just pedal a bike have never tried riding a bike in street clothes in Texas in the summer (1/3 -1/4 of our year). I don't sweat easily, and I can ride at a modest pace on the flats without sweating, but any wind, hills, or need to pick up the pace gets you sweating in a hurry. Not everyone has a shower at work or wants to sweat to make a run to the grocery store. And thus even people who might otherwise bike will take a car instead. An electric bike which reduces the exertion required can make the difference between a relatively comfortable ride and a hot and sweaty one.
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Roger 10:03AM (2/22/2009)
I think the advantage is that it may be very simple to upgrade an existing bike, as well as more reliable. Sealed against the elements, no wires or connectors. As to a little help from time to time, I don't have a car, and sometimes the 4th climb up the hill at the end of the day is a little tough.
Also, it has a generator built in to get some of your effort back after climbing that hill for the 4th time! I wonder how much can be recovered via regen braking?
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brantoken 4:07PM (2/20/2009)
It is revolutionary because someone at MIT thought of it, get with the program........
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John 10:59AM (2/21/2009)
Would like to see this as a front wheel drive.
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