0.0 Is this a CRACK?!

Discussion in 'Motorized Bicycle General Discussion' started by Mr. Minecraft, Jun 15, 2012.

  1. Mr. Minecraft

    Mr. Minecraft Visionary

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    0_0 I just remembered what i THINK caused the fail in the frame... 2 months ago, my friends goped was broken, so i let him sit on the rear rack (which i installed). The rack was mounted to the two tubes that come up from the rear axle area. We would go everywhere, over all types of ground. We did this a few times. After that is when i noticed the crack.

    Please dont give me grief over how dangerous it was. I know how dangerous it was which is why we stopped.
     
  2. Sgt. Howard

    Sgt. Howard Member

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    .

    Rag joint sprockets serve a purpose, they provide a slight cush between the rapid RPM changes and 2-stroke motor pulses to the hub.

    ... they also allow the spokes to saw through each other as the wheel flexes...


    I guess what bothers me most is you are wiling to spend almost the cost of the whole bike on a $70 hub mount sprocket to make it easier for you but you won't spring $15 for a front C brake?

    The Huffy has 12 guage spokes, double-walled steel rims and a machined rear hub. Only the Worksman has a stronger wheel. Perhaps the axle itself might not be up to scratch, but so far that has not been an issue... if it becomes an issue, I shall deal with it then. I can make any part I want.
    I was 11 years old when I apprenticed as a gunsmith/blacksmith/machinist. I achieved Journeyman at age 14- that was 1968. I know my metals. I have seriouse background in milling, design, foundry, welding, forging, engineering and several other fields. My inspection of a frame is more than visual.
     
    #62 Sgt. Howard, Jun 18, 2012
    Last edited by a moderator: Jun 18, 2012
  3. Mr. Minecraft

    Mr. Minecraft Visionary

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    So it has become pretty clear that the frame cracked because i had a 100 lb kid sitting on the back, puttin all the pressure right on the point where it cracked. Since this is true, doesn't that mean the frame should not crack under the weight on a normal single rider?

    EDIT: I noticed i forgot to put pictures of the bike, here you go!

    [​IMG]

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    #63 Mr. Minecraft, Jun 18, 2012
    Last edited: Jun 18, 2012
  4. Mr. Minecraft

    Mr. Minecraft Visionary

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  5. Mr. Minecraft

    Mr. Minecraft Visionary

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  6. silverbear

    silverbear The Boy Who Never Grew Up

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    True, it should not crack under the weight of one young rider and it also shouldn't crack under the weight of two young riders.
    Actually you don't know what caused it to crack. You're making an assumption that the extra rider's weight caused it. It might have and maybe it was already a poor weld there. Some riders of adult size weigh between 2 and 3 hundred pounds and have a motor on the rear rack or cargo and don't break their frames. When I was a kid we often had a second rider on back and I don't remember ever breaking a frame. Back then the bikes were made in the USA and most were well made to last. There is no getting around the idea that if you're going to motorize a bicycle which was not designed for a motor, then it is a good idea to have a well made strong frame. I call it peace of mind. One of my bikes was made in 1950, a Schwinn Panther... very well made in Chicago. Another was made in 1934 in Elgin, Illinois and is still a strong bicycle suitable for a motor. The frame is the foundation of your build. Let it be a good foundation you can trust.
    SB
     

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