Motor Types on Electric Bicycles

Discussion in 'Architecture & Engineering' started by elte, Dec 11, 2011.

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  1. elte Valued Senior Member

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    I see a lot of folks who build electric bicycles liking the brushless motors that, although more efficient, require a much more complicated control system. That control system is intended to try to get them to operated like a brushed motor, smooth with torque at start-up. Brushed motors are generally 10 - 20% less efficient, but controlling them is relatively simple.

    Brushed motor brushes wear out, but that usually takes a long time.

    I think that adding too much complexity to bicycles detracts from their elegance. I don't like the idea of expensive bikes, either.

    So, if you happen to prefer the old technology of brushed motors, you're not alone!
     
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  3. Aqueous Id flat Earth skeptic Valued Senior Member

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    I've never been on an electric bicycle. I would like to try one some day. I have thought about building one myself, but I would end up buying the components already in use, so it seem more sensible to buy one ready to go. Any suggestions?
     
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  5. elte Valued Senior Member

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    I have built mine from scratch; however, if I were to buy one, my first choice presently would be the Currie Ezip Trailz or something similar. It is the simplest one I know of, having a brushed motor. http://www.currietech.com/currie-technologies-ezip-trailz-for-men-electric-bike.php

    The other one that I like is the R-Martin R-10, though it uses a brushless motor that I would rather be a brushed type instead. It seems pretty good. The motor drives the pedal chain, which greatly increases it's hill climbing efficiency without compromising its top end speed. http://electricbikedistributor.com/R10_electric_bicycle.html

    The system that I built for my bike is more like the R-10 except that mine uses a brushed motor.
     
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  7. spidergoat Valued Senior Member

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  8. Aqueous Id flat Earth skeptic Valued Senior Member

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    I would be inclined towards the brushless motor just because it solves the brush and commutator friction issue. And although I might enjoy building a rudimentary controller, the one Spidegoat shows is so full of features, I would be inclined to go with a turnkey device like that.

    What about batteries? I didn't like the idea of lugging them around after they depleted, but I don't have any actual experience to go by. What's it like to run out of power before you get home?
     
  9. kwhilborn Banned Banned

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    Instead of building a motor into a bicycle, why not build one into a bicycle trailer.

    These are called push trailers and are elegant for a few reasons. They can be switched from one bicycle to another bicycle in case you want to share with someone a completely different size, and do not need to fit the limited areas in a bicycle.

    Plus you have a few extra areas to put your groceries or bags.

    http://www.youtube.com/watch?v=qJG5u-QawaI

    http://www.youtube.com/watch?v=BN65-YWGSbs

    http://www.youtube.com/watch?v=f0AaqAhW2VI

    I would imagine this would also aid in braking abilities and be safer in the process.

    With rising fuel prices I wouldn't be surprised to see electric push trailers on boats and cars soon enough.

    another one how to kind of..

    http://www.youtube.com/watch?v=7ivpYYFZhy4

    http://www.youtube.com/watch?v=5DrwlJcqexo&feature=related

    In my city it is legal to drive electric bikes (ebikes) without insurance or license. There are many scooter like models (pictured below) in the $1000 range, or less if you want to refurbish or try a used.

    posting link so you can see low prices on these as well here
    http://www.giobikes.com/Catalog/Electric-Scooters-in-Canada/

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    Yes ! NO LICENSE OR INSURANCE TO DRIVE THIS ON TORONTO STREETS. Has seat storage as well. (15km/hr governor)
     
    Last edited: Dec 12, 2011
  10. elte Valued Senior Member

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    Trailers do best for very heavy loads, yet I've found mine inconvenient in general. It is OK for those special times, I guess. If is powered in a sharp turn, it will tend to tip the bike over (esp. the type in video 1, direct drive hub motors tend to cog and drag when not powered, too).

    The ones in video 2 have pretty much rolling resistance because of the small wheels. That was a big gripe with my trailer.

    The one in video 3 has some good features, I should say, though. However, he mentioned the disadvantage that it needs to be heavy to get traction.

    The one in the 4th video I like for brushed motors

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    and simplicity.

    #5 reminds me of mine that has small fat tires and lots of drag.

    #6. Pedalability is a plus on electric bikes.

    ---

    The theoretical simplicity of brushed drive allows me to have nice features in the controller that I designed and built. It has a single transistor that controls the throttle in true current mode, something hard to do, if even possible, with brushless controllers. It's all brushless controllers to do just to keep themselves from getting out of sync and toasting themselves.

    My controller also has the battery charger built right in. I skip LiPo and use lead acid, waiting for a new inexpensive battery to be developed that has the ease of use of lead acid. My controller and charger, combined, are simpler in concept than either LiPo battery charging circuits or brushless controllers by themselves.

    All that electronics complexity adds to cost. Cost is a big reason why people stay in cars, which are a much better economical value for what they do. The bicycle has three main advantages that should be maximized, IMO--low cost, maneuverability, and simplicity. Luggage carrying ability is important, too. That is why I like unsuspended bikes. Theynot only are simple, but they can also be loaded down a lot without overloading the suspension. I like simple road bike ten speeds.

    ---

    It is a good idea to keep the bike simple and light so that when the battery goes flat, the bike is still easy to pedal.

    I'm quite opinionated on all this I suppose.
     
  11. kwhilborn Banned Banned

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    Many people in Toronto are switching to bikes from cars mostly due to the no insurance required thing. A 16 (min age limit) year old or college student would be smarter to have 1 or 2.

    I was an avid cyclist, and had a fitness based lifestyle, but am not anymore as I am much older and lazier.
    I agree 10 speeds are best for the road if you are pedalling, but find the tires somewhat fragile and more prone to flats.

    If I was riding to work everyday a standard 10 speed would be my preferred choice as well, and could never understand the popularity of mountain bikes on the road.

    For an electric bike I would probably opt for the slightly heavier and shorter wheel base of a mountain bike. For the record I have damaged a 10 speed (and myself) hitting a car door, and also had a 10 speed flip frontwards after wedging its thin tire in a streetcar track.

    I have had some very nice bike trailers, and my first was the huge chariot model for my kid(s). I must say that I also enjoyed using it for grocery shopping, or carrying items (once I carried a large television from a yard sale).

    I had not realized from the OP that you have had a background with push trailers or I'd have not tried to sell them as much, and certainly didn't know there was any dangerous aspects to them.

    I do like that a trailer like in video 2 could be brought inside the workplace and home much easier than an entire bicycle would. In the event the bicycle itself was stolen any cheap bicycle could be used to replace it. I wouldn't bother with a high end bike if it was getting pushed.

    I recently went to a show and saw what looked like golf carts (with roof, and sides), but they are considered ebikes and are road worthy in toronto. I have yet to see one on the road however.

    I think the escooters are nice and affordable, however I think there will soon be enough injuries on them to require licensing and insurance. Your trailer could be disguised as a kids trailer and any police that dislike them on the road would just think you're a sweet family guy.

    Anyways, sounds like you are better informed than I am already.. good luck.
     
  12. elte Valued Senior Member

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    Thanks for that encouragement.

    I sure notice how I am not immune to soreness like in my days of youth. So I can understand your giving up cycling. I do it to save money, to relax, and to avoid the hassles of cars, like stressful traffic, expense, and the hassle of maintaining that big thing. By rarely using the car, I save a lot of money on its insurance.

    One thing I really like about road bike ten speeds is the racing handle bars. A comfortable riding tuck can be nice.

    I see an unfortunate direction in the ebike field that will eventually sadly lead to them being licensed. I may just have to give it up and take up a new hobby then, because that would just ruin the whole idea for me.

    I might have errantly given the impression that my trailer is powered. It sure does drain my battery due to rolling resistance, though. It seems to show the importance of wide diameter wheels on a trailer.
     
  13. X-Man2 We're under no illusions. Registered Senior Member

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    I'm old school and running a 6.5 hp has engine pusher.I'd rather have electric powered but the cost is to astronomical for the distances I travel.Iv'e been riding this gas set-up for about 3 years.The build ran me about 300 dollars.
    I get a lot of people wanting to talk to me about my rig,the usual questions.
     
  14. spidergoat Valued Senior Member

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    That's a bigger engine than is allowed in many states.
     
  15. X-Man2 We're under no illusions. Registered Senior Member

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    Actually its quite illegal here too BUT every police officer that passes me just smiles or gives me the thumbs up.I think here at least its all about how you conduct yourself while riding.

    There are quite a few electric bikes out too who are also illegal.Again it's your conduct in my opinion.
     
  16. spidergoat Valued Senior Member

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    Here is the one I want to get.

    It's built specifically to take the engine, a high quality 35cc Japanese made model, and it runs through all the gears.
     
  17. elte Valued Senior Member

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    I do my electric drive through-the-gears, too.
     
  18. scorpius a realist Valued Senior Member

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  19. elte Valued Senior Member

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    I recommend going smaller and lighter weight than the one in that first video so that pedaling is easier when using only pedal power.
     
  20. leopold Valued Senior Member

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    there are 3 reasons i would opt for a car over a bike, specifically my bike.
    1. weather. i can't ride in temps below about 45 F.
    i can't ride on ice.

    2. carrying capacity. a car can carry at least 30 times the load of a bike.

    3. safety. 2 wheels are inherently dangerous.

    if cost was the deciding factor then i would ride 24/7.
    i can operate my bike at a far lower cost than i can my car.
    60mpg and insurance at 110 a year.
     
  21. elte Valued Senior Member

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    The wind chill effect is very nonlinear, indeed. I find it too cold to ride below about 50 degF, and that is much slower on a pedal only bike.
     
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