Coaster to Drum Conversion on your motorized bicycle

Discussion in 'Instructions for Building and Repairing Motorized ' started by UncleKudzu, Aug 19, 2008.

  1. UncleKudzu

    UncleKudzu New Member

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    Reprinted with gracious permission from original submitter, bikebuilder, from this thread . many thanks to bikebuilder!

    Someone asked me to explain how to do this. This particular brake setup is the easiest to modify. The one on my bike was more difficult. The center mass or the "ball" on this one is in two peices. All you have to do is weld the two peices together so that it cannot reset it's self while riding. Reassemle the hub and weld a lever on to where the gear used to be with holes front and back. front for the hand lever and the back for a spring. Make sure that the lever you weld on is in the best position possible to work with the hand lever.

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    The one on my bike had the ball in one peice already but did not have that little peice sticking out between the pads to hold it in place. This would allow it to reset. So I had to weld a little nub on the ball.

    This conversion works pretty good. I can leave black marks with the one on my bike. The one I put together for "little brother" 195lbs would lift the back tire off the ground.

    You can see it in use a little watch the video linked in the rat-rod swingbikes post

    ratrodbikes.com • View topic - Rat-Rod swingbikes
     
  2. UncleKudzu

    UncleKudzu New Member

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    Re: Coaster to Drum Conversion

    Reprinted with gracious permission from original submitter, bikebuilder, from this thread. many thanks to bikebuilder!

    (below is response to this question: "ok, after thinking about this i have a question: why isn't the forward motion of the wheel enough to throw the hub back into "drive" after braking? you can brake and coast, brake and coast with the hub on the rear, so why not on front? i'm not understanding why any internal weld is needed.")

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    The area with all the dots on it is the main focus. On the bike I ride this was one peice and the "nub" where the blue dot is did not exist. I made one. On this one the "ball" is in two peices which allows it to reset so in a rear coaster situation it can be activated at all times. when using it as a drum brake if you let the brake reset. you will get one good stop and then it will reset. The brake arm where the gear used to be will change position and you won't be able to activate it again. Back to this brake. I will just have to remove the spring holding the ball together and weld the two peices together along the green dots. I fully anticipate lifting the rear wheel on the bike this brake is going to be on. The key is that the the part above or behind the area with the dots does not change it's relationship to the cable and lever.
     

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