Geared motorized bicycle... on the left side?

Discussion in 'General Questions' started by ionia23, Jan 2, 2016.

  1. ionia23

    ionia23 New Member

    Hello all,

    I've been riding about 8 months on a motorized bicycle. Great option for those without a driver's license who can't rely on public transportation.

    Regarding gearing, I'm already familiar with using jackshafts to enable gear shifting. I'm pretty sure the answer to this is a no/wouldn't work, but has a gearing system ever been designed for the left side of a bike?
     

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  2. johnsteve

    johnsteve Member

    I am no expert, but maybe a sturmey archer hubsmight be the way to go, because all gearing is done inside the hub and you dont have a derularer bobing up and down when you change gears.

    having said that, great care needs to be taken that somone does not go over 20 mph, and risk getting a ticket.
     
  3. MacZulu

    MacZulu Member

  4. skyash

    skyash Active Member

    i think from the motor to a bike cassette on the left to the sprocket on the wheel
     
  5. Nanonevol

    Nanonevol Member

    The problem is that bike components are made for the right side transmission. In particular, freewheels both for wheels and bottom brackets are designed to work on the right side. If you flop your freewheel to the other side it's going to drive you backwards. I'm with you, though. We have motors with driveshafts on the left. Sure the jack-shafting works but it would be nice to not need it.
     
  6. Nanonevol

    Nanonevol Member

    Here's an idea. Sturmey-Archer and maybe others make hubs with reverse gear for use on tricycles and quadracycles. I wonder if they freewheel in reverse? Then you could flip the wheel and put it in reverse and you'ld have a left hand freewheeling sprocket (with 3 or more reverse gears:))
     
  7. MatthewMore

    MatthewMore New Member

    anyone who rides freestyle or street bmx knows that anyone can buy a left hand drive rear hub or left hand drive rear wheel, from any bmx parts site for the same price as another wheel or hub... i assume the same thing could be bought for a mountain bike or cruiser...
     
  8. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Um, no. Not with gears.
    That's something you'll have to invent for yourself. :)
     
    MatthewMore likes this.
  9. MatthewMore

    MatthewMore New Member

    yeah, i suppose. there must be single speeds available for mtb/cruiser with left hand drive..
     
  10. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Um. No. LHS drive hubs all take 14mm axles, which are 14mm for the strength to take stuntpegs... BMX.
    Only reason for LHS drive is doing grinds on ramps if you prefer to rotate ccw like most right footed and right handed people do.
    Larger than 20" wheels make grinds very difficult even if you chose to use 14mm axles and put stuntpegs on.
     
  11. MatthewMore

    MatthewMore New Member

    um. ok. youre right.
     
  12. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    From recent threads it seems Grubee make a both side drive hub mainly I suppose for the 4-strokes.
    If you have a pull start and the wide cranks that pull start requires, and you buy their opposite thread left side freewheel and sprockets then you're all set. :D
    Just have to make a way to change gears and keep good tension then. :)


    (I think it would be easier with the freewheeling sprocket, but I don't personally want to have to use a pull start, so I'll have to try a fixed sprocket system.)
     
  13. gary55

    gary55 Well-Known Member

    Wouldn't all it would need is the shifter hub manufactured with a left hand free wheel? I'm using the Nuvinci and it seems that it would work if the ratchet and pawls were just reversed. Don't know if their would be enough demand to have the design change implemented, but it sure would be nice to eliminate all that extra drive train weight and resistance.
     
  14. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    I think IIRC someone already asked the makers of the Nuvinci to make a mirror version and was told it just isn't going to happen. It would be great though if it was to happen. :)


    A derailleur based two (or maybe three) speed system should be easy enough if you don't mind stopping, getting off your bike, putting the kickstand down, pull starting the engine. . . .
    I would certainly be very confident about the derailleur based system if it had the freewheel mounted sprockets like the Grubee HD hb apparently can have.
    I'll have a go at throwing something together without it though. It's already going to be expensive (but less than the Shift Kit) even without the special hub, freewheel and sprockets imported from America.
    Of course the Grubee sprockets would need to be modified a bit, made narrower and perhaps with some shift ramps and shortened teeth to mimic normal geared bike sprockets.
     
  15. Frankenstein

    Frankenstein Well-Known Member

    I'm with you on the nuvinci, the design is particularly simplified when it comes to power transfer from the sprocket to the wheel, it's a reversible design in that area. If you somehow reversed the paws it would almost definitely work, I also would think that locking the freewheel up could do it if you had a freewheel before that cog, like how the bullet train runs a one way clutch just before the drive gear, then it wouldn't need any real modification.

    Other than that the options aren't great without using a jackshaft, you could probably use other internal gear hubs if the design allowed them to run in reverse but still leaves freewheel related issues to kink out.
     
  16. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Not to mention reduction. You need to get the right size sprocket with the right type of mount to fit the hub.
    Idk what the Nuvinci uses for sprocket mount, but I wouldn't be keen to experiment with trying to reverse the freewheel if it's built in, lol... those are expensive hubs.
     
  17. gary55

    gary55 Well-Known Member

    Then once you stop to think about it not only is the reduction a really big issue but you no longer have a motor assisted bike. I mean what are the pedals doing. I'm beginning to like my j shaft more be the minute.
     
  18. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Oh yeah hahaha I wasn't even thinking about that. :oops::rolleyes: The pedal chain would have to go to a rag joint and have its freewheel at the crank. That would really suck! :confused:
     
  19. Frankenstein

    Frankenstein Well-Known Member

    If you are daring you can do the flintstones thing and run around to start it should you decide to omit the freewheel you could shift with the right hand and use a thumb throttle... Using brakes might be hard...

    If other internals could handle pushing an underspeed engine without demolishing and used a thumb shift it may work better..

    Reduction is subjective, use a 9t drive and a mid sized gear and don't forget a nuvinci swings 180% both directions, a 28 cog is like having everything from a whopping 50 tooth down to a 15, you can get slightly larger single cogs that fit BMX style bikes and other fixed hubs, just get one that covers what you need. 9t on a 50 is similar to a 10t drive to a 55 rear, pretty good for pulling out though you'd probably never use the highest gear ratio.

    Anyway as far as cranks go you can always left hand side the sprocket and maybe freewheel the connection there but that's no better than a jackshaft, at least you can buy a ready made kit lol
     
  20. gary55

    gary55 Well-Known Member

    With the resources and creativity it could be surely done. I'm not up to the adventure. As for the gearing the minimal approved under electric power is a 33 chaining ring with a 16 cog. With pedal power you can pair the 16 to a 30. At no point is the drive gear to be less than1.8 of the cog. It's range is not equal in both directions .5 underdrive to 1.8 overdrive.
     
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