Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

electric bike design suggestions

Discussion in 'General Motorcycling Discussion' started by moni, Aug 18, 2007.

  1. Hello,

    Im an industrial design student at QUT in brissy and we have this assignment, designing an electric commuter vehicle. My groups decided on a motorbike (the guys all ride) and my boyfriend told me about this site (he had some starter motor issues) anyways, i thought id post here to find out the opinions of people other than uni students.

    Our brief is pretty simple:

    'To design a solar powered electric commuter motorcycle that can travel at least 100km's.'

    before you freak out and start imagining a bike covered in solar panels, the power will come from excess solar energy produced at home (half of the class is working on this).

    Obviously a lot of ideas can come from that brief because it is so broad, that hopefully is where you come in...

    what would you like to see in a motorbike?
    what should we bring across from existing bikes?
    what would you like to magically disappear?
    is there something that really bugs you on your way to work?
    do you have any major issues when you hear the word 'electric'?
    if your mate said they were selling their crazy good bike and going green and getting an electric one, what would your reaction be?
    would you get one if it was awesomely awesome like most bikes are :)

    any comments/suggestions/ideas would be greatly appreciated, no matter how crazy or random.

  2. Hello, and welcome.

    Personally, for me an electric bike would be somthing I wouldn't buy (you can't go touring with them), but for a city bike, some basic principle ideas come to mind -

    Outlandish designs would definitely not be appealing to the mass market, seen pictures of too many concept bikes that just don't fit bill (including that "'80s BMW white" design that was on the forum a while ago)

    Needs to be narrow (think small capacity sportsbike dimensions) to enable quick city riding

    Needs to have usable power on tap, too much "wind up" can lead to being in the wrong spot at the wrong time

    Needs to be nimble and comfortable to entail agility and livability.

    Needs to have a decent range (250-300ks)

    Neets to be able to go fast enough and be well balanced enough to enable it to be taken for spirited rides.

    Needs to be sub $8-9000 to justify its shortcomings and put it in a more competitive market

    Been discussed plenty of times before:







  3. You are technically designing a battery-powered electric motorbike.

    I will give you some ideas.

    - Regenerative braking (turn kinetic energy into electrical energy when slowing down or stopping :arrow: efficent energy consumption)
    - Application-specific materials eg. hollow Mg-alloy frame (weight saving + good mechanical properties for this sort of application)
    - Light wheels with low rolling resistance tires :arrow: less energy req. to get it rolling
    - High energy density batteries (it's gonna be heavy; might as well get something that can store more energy per kg; memory effect & charging duration come into the play as well)
    - Aerodynamic body (low drag coefficient)
    - Efficient electric motor (it's highly likely you'll end up with a good ol' brushed because of weight issues)

    Excess solar energy produced at home? :roll: Have you done any math? Unless the home is located in the middle of Sahara desert, you will need pretty big panels. I mean f@#*ing huge ones. To recharge a bike capable of doing high speeds and carrying a fat individual and itself to a location upto 100km away . . . oh, boy. :cry:

    Perhaps go with fuel cells. No, not the liquid H one.
  4. LOL, if that was simple we'd be all riding them by now! Electric engines are quite capable of providing good acceleration and top speed more than sufficient for a bike. Unfortunately, batteries are not up to the task of providing required range. To be in competition with petrol, electric bike must be able to travel at least 150kms, and when I say travel, I mean travel in real traffic conditions, not under ideal and absurd ones like those 100kms advertised for Vectrix, which under closer scrutiny turn out to be calculated 'at steady 40km/hr', Half-truths like that are worse than lies.

    Also, I think the essential part of your brief should be: "The bike shall cost no more than a petrol-powered one of equivalent performance". In other words, if you're going to produce something barely capable of rolling down to the corner shop - which is where electric bikes are at current level of technology - then it should cost no more than an average 125cc scooter.
  5. I think the challenge is to make higher efficiency solar panels.

    I think the challenge will be weight, styling and price.
  6. Electric scooters are just about practical... there are a couple available already (yes expensive and short range), but they are getting there.

    The problem is one gets 125cc performance, 50cc range and 500cc weight at the moment.

    I'd suggest your design should be focusing on a commuter type electric motorbike... or if you want to go way out in west field then just possibly and electric drag bike. Drag bikes don't need huge batteries because the demand is short term and some success have been achieved with them.
  7. Sparked an idea - can be done on a conventional motorcycle quite easily- if the wheel diameters are to be similar to conventional motorcycle wheels, a solution can be achieved using rim-mounted discs and a central brushless generator on each wheel, with a load-bearing generator case.
  8. Yeah at this stage I don't think you could design an electric bike that would be competitive in both price and performance, and I don't think solar power would work too well for anyone living in Melbourne or Tasmania.
    A more effective system would be to use a small petrol engine with an electric motor coupled to a capacitor (lighter and more efficient than a battery) for regenerative braking that can then be used for extra "boost" under acceleration. After all most acceleration is done after heavy braking (ie out of a corner or away from a set of lights) so as long as the capacitor can hold the charge for a few minutes it'd work. This is the same system I believe Toyota used to win a recent (car) endurance race in Japan.
    Probably not going to be useful for your project but it is something I reckon electric bike designers should be considering at least until technology makes going 100% electric more feasible. Of course then you have the issue of no-one being able to hear you coming, which is a danger to both riders and pedestrians (at least the stupid ones that don't look for traffic). One plus side to electric though is that it should significantly reduce the need for servicing - which is a cost/time advantage that might persuade people to pay more initially. My biggest issue with electric bikes at the moment is that typically they're made small and/or extremely light - not always an advantage for a bike doing 100+kph on the highway. And of course the "greeness" of electric, even with solar power, can always be a little questionable unless you can account for the total environmental cost - ie the resources/energy in making the bike/battery/solar panels, environmental impact of disposal, lifespan of the bike compared with conventional petrol etc.
  9. There's your problem. *Industrial design*, not Engineering.

  10. Was just about to say the same thing! You dont actually have to make it work do you? Just more about the actual design and how it looks, as opposed to functionality yeah?
  11. Maybe for some extra juice while riding, maybe add some solar panneling to jacket and helmet surfaces?
  12. Here's some of the stuff we've written about: http://tinyurl.com/2vun9n

    Electric bikes sound very exciting to me - 100% torque from 0rpm, motors as powerful as you want them and very low maintenance to boot. Battery technology is the holdup, but even that's improving day by day. Somebody built a battery-powered Daytona 600 recently that would beat most bikes to 100kph, and there's a few commercially available commuter scoot types that, when the price drops, will be sensational little round-town machines.

    I for one welcome our new lithium-fed masters.
  13. I'm with you Loz, electric is the way of the future! Well, maybe...

    Once they figure out a way to make the batteries smaller and most importantly lighter, we may be seeing more things like this on the road
  14. +1

    The combination of a roaring engine and speed are exciting, but so too is the possibility of speed and...silence........ (maybe with a bit of opera)
  15. My mum has an electric bicycle. It runs on 3x12v batteries in series (about 10kg) and would be lucky to do 20km/h for 10 minutes if you didn't pedal as well. I'm sure you can do better than that, but the design specification of 100km range is only going to be possible if you're riding in circles around a powerpoint with a charger attached.
  16. [​IMG]