Custom Bike Problems

Discussion in 'Motorized Bicycle General Discussion' started by Austritch, Apr 16, 2016.

  1. Austritch

    Austritch New Member

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    Hey! I am building a fat tire (mongoose dolomite) custom frame and gas tank bike. My mandatory specs were that it had to have disc brakes front and rear, 4 stroke motor, and shift with no manual clutch (shifter kit from Bike Berry). The problem I am having seems to be that the 49cc motor (also from Bike Berry) is under powered for the gearing and is frying my centrifugal clutches. I am thinking about going with a 150cc Gy6 motor. Do you think this is the right thing to do? Perks to the Gy6 motor are that parts are readily available, speed will be more comfortable, and a kick starter. My build is more of a motorcycle style than a pedal bike.
     
  2. curtisfox

    curtisfox Well-Known Member

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    You are geared to high,heating up clutches and under powered, You need to get a bigger rear sprocket for the rear...............Curt
     
  3. Austritch

    Austritch New Member

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    Thanks Curt! I am still trying to utilize the original rear cassette and shifter so that I may run through all 7 gears for a more useable ride. Rather than going with a larger single gear, I am thinking about using a more powerful motor. Hence the 150cc Gy6. Does anyone have any experience with using a Gy6 on a motorized bicycle?

    While I have the bike on the stand, it will run perfectly fine and shift through the whole cassette. But while under actual load, it barely moves under its own power.
     
  4. Tony01

    Tony01 Active Member

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    You can use all 7 gears but you'll still need a reduction ratio of around 14:1 for the middle gear. You need to give us information on your gearing. A bigger motor with the wrong gearing will fry the clutch too.

    Also a bigger motor will destroy the little bicycle chain and cassette sprockets. You need to decide whether you want to shift gears with the little motor, or move up to a larger one using single speed, cvt, or 2-speed auto.
     
    #4 Tony01, Apr 18, 2016
    Last edited: Apr 18, 2016

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