Motocross / Off-Road Bikes

Discussion in 'Electric Motorcycles' started by Moto Jimmy, Jan 12, 2018.

  1. Silviu Gheorghiu

    Silviu Gheorghiu Adventurer

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    Before I bought my DR350 I built two electric bicycles - a rear tire friction drive with an RC 63mm motor that kinda failed because of the concept - but when it worked the very small weight and 600w of power felt amazing. The second one was a Smart Pie hub motor from Golden Motor, completely silent, weird handling because of the weight and finally had to be scrapped because the battery I needed was the price of the DR350.

    I studied electric propulsion for a year, more pages than I can remeber on Endless Sphere forum and alot of other sources and now I'm pretty sure I know the basics to convert my DR350 to electric if batteries would be cheap enough and have the required range.

    In every discussion I see on forums and social media there are the guys that understand the laws of physics and the ones that don't.

    A pure electric motorcycle has to have the motor in the frame not just for suspension reasons, but for heat dissipation, power delivery through wires exposed to flexing and damage from rocks etc, swingarm stresses from motor torque, much heavier axle and bearings, much harder to fix a flat etc.

    Tacita motorcycles have a gearbox and clutch. Any electric vechicle having a gearbox should raise a red flag regarding the engineering department. Tesla had a two speed but kept braking it so went single speed, Alta single speed from the start, Zero the same, diesel electric trains are single speed. You get the idea.
    #41
  2. mousitsas

    mousitsas Long timer

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    Very well said!:beer
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  3. Moto Jimmy

    Moto Jimmy Bushwacker

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    Cool! It's good to see Alta starting to make a presence at local races (all types). I expect to see their new models make real headway at the local / regional level. I wonder when it will happen at the national level though, rules and regulations will have to change first. I expect the big four will fight against it until they develop an electric model.

    Regarding my comment, I did not doubt the capability of cold weather operation, it was just about long term storage in the cold (off-season & unused). :-)
    #43
  4. Cat0020

    Cat0020 El cheapo

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    I have used hub-motor on my (sub 70 lb.) MTB also, heat dissipation, suspension, weight distribution was never much of a problem for off-road riding (approx. 200 miles) in the NE PA area ski trails.

    Little planning to experiment where to place your battery pack, pick the right tires and know your pacing through the trails will accommodate the utility and longevity of your EV more than picking any specific equipment to use on a bicycle with electric motor.

    I did not rely on the hub-motor for sustained usage since it was a MTB; I considered the main source of the power output was my legs and used my hub-motor only when needed (which reduced or eliminated the heat dissipation problem).

    Ultimately, it was the frame that failed on my bike, not the hub-motor, nor its performance.
    #44
  5. marbee40

    marbee40 Some Fear is Good Supporter

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    Kinda the same way “motor”-driven cycles started over 100 years ago.


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    #45
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  6. marbee40

    marbee40 Some Fear is Good Supporter

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    I’m not technically smart enough to debate anything with the guys above. I have been dreaming of a semi-silent two wheeled conveyance for years. It will need to be reliable, handle 3-5 foot G-outs at 60+ mph, and do around 100 miles before recharging. Street legal would be a plus. Under 250lbs would be dreamy. I am excited with the direction these bikes are headed and can’t wait to see whats right around the bend.


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    #46
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  7. keepshoveling

    keepshoveling DNF

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    Please stop. Any point you had has been long lost in your presentation and you’ve clogged up half this thread already with “but guys, what if... hub-motor!”
    #47
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  8. Cat0020

    Cat0020 El cheapo

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    As if your post has any contribution to topic?

    Motocross riding vs general off-road riding are somewhat different in between.
    Without specifying parameters of vehicle performance expected of these machines, one cannot compare whether either motor type or drvetrain type is better suited.

    If you don't have anything to contribute to the topic, you should stop posting yourself instead of worrying about others.
    #48
  9. rick danger

    rick danger The further adventures of

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    I remember my '89 bronco having no clicking sound with the turn signals. I frequently left them on. Manufacturers I think, figured that out and they have the familiar relay click sound again. Maybe just artificially produced. Old habits die hard. Maybe they will create an artificial vroom vroom sound to help people transition. :lol3
    #49
  10. Moto Jimmy

    Moto Jimmy Bushwacker

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    Anyone remember these from Mattel? Turned my bmx bicycle into a real ripper! Maybe they'll make a comeback for the electric bikes...

    IMG_7633.JPG
    #50
  11. dirt hokie

    dirt hokie Long timer

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    Here is a question, why don't off road bikes( minus a pw 50) have shaft drive, even trail bikes where all out performance is not a priority. So if you want the eliminate the chain, and also the motor weight from the wheel, that would be your answer.
    #51
  12. MarylandStrom

    MarylandStrom Long timer

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    From what I understand, shaft drive is heavier than chain drive. But I agree, a shaft drive would be great if it held up. I do hate chain maintenance.
    #52
  13. Moto Jimmy

    Moto Jimmy Bushwacker

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  14. dentvet

    dentvet Long timer

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    That statement make way more sense in the other threads but not in the offroad thread. We need 0 mph up to 60+ mph. 0% traction to 100% traction. shooting up hills from a standstill with no run up etc etc.

    The twist throttle mechanism has a finite range of motion. The gearbox and clutch makes the twist throttle infinitely adjustable (with respect to how the bike reacts) when combined with the software in the human brain.

    Computer software that doesn't account for the possible inputs from all available sources (2 hands, 2 feet) will be less sophisticated than a clutch/throttle/gearbox assembly in the offroad environment.
    #54
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  15. dirt hokie

    dirt hokie Long timer

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    Gearbox vs no gear box would come down to how robust and adjustable the power delivery programming of the controller is.
    sometimes you want to be able to slip the clutch or dump the clutch while keeping the engine at high rpm, so you have full power available instantly. With no clutch and only throttle, you have no option but to roll the throttle with a smooth power delivery.
    #55
  16. Silviu Gheorghiu

    Silviu Gheorghiu Adventurer

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    What about ride by wire? The pinnacle of engine control. It extends the possibilities of controlling a very powerful engine much farther than humanly possible.
    Controlling an electric motor is much easier than an engine. Even my cheap chinese Golden Motor controller had a well calibrated power delivery.
    I wish I could test ride an Alta. A bike many articles written by experienced riders say is superior to many 250cc bikes.
    #56
  17. voltsxamps

    voltsxamps Advolturer

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    Exactly. One of the benefits of EM's is it's ability to climb smoothly with minimal throttle effort. Loose dirt? Dial in one of the MAP settings for the terrain and you're set or change the MAP settings on the fly as the terrain changes. Need power instantly? Just crank the potentiometer/throttle wide open and hold on!
    #57
  18. dirt hokie

    dirt hokie Long timer

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    We I am curious how well electric works off road, I just wish they would get better faster so i could buy a legit E-dirtbike second hand to try out.
    #58
  19. XDragRacer

    XDragRacer Long timer Supporter

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    AVIONICS encompasses a system known as a, "Stick-shaker."

    Modern fly-by-wire aircraft in some aspects provide no feedback through the controls, denying the pilot of tactile identification of flight phenomena, such as . . . STALLING, a condition possibly critical for maneuvers, possibly dangerous.

    Conventional aircraft with mechanical aerodynamic control surfaces interface, when approaching stall conditions, shake the "stick," or yoke, the main attitude control cockpit device. With computerized, "fly by wire" systems, no such feedback is available--control dynamics are the same, whether in sustainable flight or in stall conditions.

    Enter the, "Stick-shaker:" A device physically shaking the stick, replicating the mechanical feedback of yesteryear, in hope of informing the pilot of aerodynamic conditions. Computerized sensors detect aerodynamic stall conditions, activating the Stick-shaker when such lift/gravity/thrust/drag conditions occur.

    Hence: An argument for an artificial "sound-track" of an internal combustion engine, on an electric motorcycle! :lol2

    Motor sound-effect audio, mimicking an internal combustion engine under similar riding conditions, will resonate with the rider's expectations, informing him of the bike's dynamic status.

    O.K., O.K.! Not unlike a playing card clothes-pinned to the fork and inserted in the spokes of a bicycle wheel; remember? :D

    DISCLAIMER: No pilot, I; my understanding of the Stick-shaker rationale and functioning only.
    #59
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  20. Mayomoto

    Mayomoto Neuroatypical

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    It's a well known fact that Henry Ford's engineers developed the backfire to replicate a horse fart, so there is precedence.
    #60