CVT for 3 hp electric??

Discussion in 'General Questions' started by jawnn, Jan 5, 2016.

  1. jawnn

    jawnn Member

  2. KCvale

    KCvale Motorized Bicycle Vendor

    Consider using a right side fixed toothed belt or geared reduction drive, and then do the shifting via an internal geared rear hub.
    CVT's are power sucking leaches as it all relies on friction which is what you DON'T want.
  3. jawnn

    jawnn Member

    I know the guys on this forum have been using a small cvt for many years. I finally decided not to worry about the wasted energy because of the new steel v belts. not that I have found out if they make one to fit, yet.

    I do not think anyone makes a geared hub that can handle even 2 HP with out fast decay.

    is this the one?


  4. jawnn

    jawnn Member

    I really do not think that any hub gears made for bicycles can handle a two or three HP motor.

    I know the guys here use a small cvt, and with the new steel belts (if they fit) could be more efficient.

    is this the one? has any one used a steel belt?


    Last edited: Jan 15, 2016
  5. KCvale

    KCvale Motorized Bicycle Vendor

    Best of luck with deifying the laws of drag and friction.
    Just don't come wondering why you have no power left on a <125cc engine to the road.
  6. jawnn

    jawnn Member

    maybe you should tell all the other guys on this forum that kind of thing. Or maybe it does not apply to gasoline motors?????

  7. HeadSmess

    HeadSmess Well-Known Member

    yay, a picture of a self adjusting steel "vee belt"

    now consider all those little plates, sliding past each other, several hundred times a second...

    those lovely steel bands, flexing several hundreds times a second, bending, rubbing, fatiguing...

    now consider a bit of grit getting in between what has to be extra thin steel to be flexible...

    not much material left to grind away.

    nice little chunks of metal that when worn out finally become small razor like projectiles...

    whats keeping the two sets of steel bands lined up?

    are they continuous? or is it a big long spiral strip?

    i know im changing bandsaw blades after only a few hours...they run slow, dont flex much...but always break at the weld. never go blunt. break at the weld first. gunna enclose this steel belt in an oil bath? sealed you know?

    then... do these plates just grip the sides of a pulley? so its got hardened faces so they dont wear out into notches? has really heavy duty bearings to take both radial and thrust loads?

    seriously heavy duty bearings.... like truck-hub size taper rollers....

    or are they toothed? makes sense, the small link plates simply spread apart and come together as required... cus the teeth are these radial things like bevel gears...(which are known to be the hardest gear of all to cut, even compared to hypoids, and they get harder as the faces get closer to a flat surface.)

    sliding along those steel bands. rocking., pivoting on those steel bands. clicking clacking and grinding away on each other on those steel bands.

    im not quite sure what rocks them over and spreads them out so they engage with the teeth smoothly?

    looks like a design that wont really get past a cad drawing. is that really a n 11 year old image? so wheres the actual product?

    and all of this on an electric drive system that doesnt require a gearbox at all. other than a suitable reduction.

    (admittedly two or three speeds is nice, and the brammo does have a 6-speed, unlike any other production electric motorcycle)

    seriously, if you want decent gears on an the forum. someone posted good plans for a two speed box thats very easy to copy/change ratios on way back...
    Last edited: Jan 9, 2016
    Timbone likes this.
  8. jawnn

    jawnn Member

  9. KCvale

    KCvale Motorized Bicycle Vendor

    You are suggesting a Gas 4-stroke Centrifugal Clutch transfer case for an ELECTRIC motor?
    You are aware you don't have to 'start' an electric motor and let it idle correct?

    Jezz I can't even see that on a 4-stroke bike, it would be like bolting an engine to the side of your engine to hang out.
    And for just a high and low gear?

    Anyway, I digress, I am still trying to wrap my head around what you were thinking to even suggest a centrifugal clutch be used in any form on an electric bike, they don't need a clutch at all, that is part of their beauty.
  10. jawnn

    jawnn Member

    this is for a large very heavy cycle truck.......and yes I cna make the gears smaller. even with out a clutch.
  11. KCvale

    KCvale Motorized Bicycle Vendor

    Ahh, OK, clever design for a high and low for something that big and demanding.
    For an electric bicycle it's easy, no clutch needed.