Ez Motorbike Gearbox

Discussion in 'General Questions' started by bikeman6969, Apr 6, 2010.

  1. bikeman6969

    bikeman6969 Member

    Hi I was wondering if anybody out there has an EZ MOTORBIKE GEARBOX,and if you do how is it running?
    Mine is not so good: Clutch slips, belt slips, and does not go nearly as fast as they claim. It is not that they are not working with me, but I am on gearbox #2 and 3 different belts and still it does not get out of its own way.So if anybody else is in the same boat I would like to hear about it.:confused: thanks.

  2. Gh0stRider

    Gh0stRider New Member

    Does yours have the new belt tensioner design where the belt is pushed out? They redesigned the system to achieve a 98%+ efficiency and an increase in top speed of 2 mph. (I don't know what the top speed used to be) You can read more about it here -


    Maybe they can toss you a free upgrade since you've had so much trouble.
  3. bikeman6969

    bikeman6969 Member

    yes i do and it is still slow
  4. azbill

    azbill Active Member

    what rear sprocket are you running ???
    I am using a 72tooth and can still hit 30mph
    my bike is a tank (90 lbs of stretch cruiser), and does hills fine, even pulling the trailer with the girls :)
  5. loquin

    loquin Active Member

    98% ??? Has that been verified in the lab?

    Power transmission efficiencies with VBelts are in the 95% range. Synchronous belts (ala GEBE) and chains are in the 98% range though.
  6. Gh0stRider

    Gh0stRider New Member

    Quenton said that engineers at various companies arrived at that figure through computer models and actual hardware testing. I'm not sure if they used an actual EZM system though. But the claim is pretty darned good for a v-belt drive!
  7. KilroyCD

    KilroyCD Active Member

    Bikeman, what engine is your drive mated to? That could be playing a part in this.
    I have one of the first generation EZ drives (the "Silent Drive"), which is the one with the manual instead of the centrifugal clutch (Q-Matic). With that drive mated to the 49cc HuaSheng engine, I have reached 35mph with my 300lbs in the saddle. I have a 48-tooth rear sprocket. I have also ridden two bikes with the Q-Matic and found similar performance with the 49cc HS-engined bike and lower performance with one that was mated to a Harbor Freight 79cc engine. This is a lower-revving engine than the HS, and the clutch on the Q-Matic is optimized for the higher-revving HS engine. As a result there was more slippage at the lower RPMs.
    I've got one of the new Q-Matics coming soon (with the new belt and idler design), so I'll be able to do an apples-to-apples comparison since it will be with the same bike and engine.
  8. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Craig,

    Call me at 252-475-0406.

    If your Q-Matic has the front drive pulley with "EZ Bikes USA" etched into the pulley, it could be the problem. We found some of the pulleys cut at the wrong angle, [not all, about one in twenty]. We have currently stopped shipping the custom made pulley and all kits are currently shipping with the "Congress" brand pulley. The defective pulleys "pinch" the inner runner of the belt and caused the belt to run hot, cause it to drag, and in extreme cases the belt "chunked".

    The idler was re-designed because of power transfer, and not because of belt issues, if the drive has one of the defective pulleys it doesn't matter which version of the idler is used.
    The defective pulley can cause several issues including slippage, rapid belt wear, drag and reduced power transfer.

    This was a difficult issue to identify because only a very few were effected. To make it harder to identify only a few Q-Matic drives sold as separate units had issues. All drives contained the same parts, so why were only a very few having problems? All the pulleys were made on a CNC machine; therefore we thought they were identical [they weren't!].

    Anyone with the suspect pulley can contact us for a free replacement.
    I will attach pictures of the pulley and the "Congress" brand replacement.

    Have fun,

    Attached Files:

    Last edited: Apr 10, 2010