Very bad vibration.

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

  1. donphantasmo

    donphantasmo Member

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    I had a very bad vibration on my bike. It's a Panama Jack, 66cc Grubee, no shift kit or nothing (since it's a single speed, right?). Springer front end, front brakes, banana seat, speedo and rear mirror.

    So, when I go past 15-17, I get a really bad vibration in the bike. I can not pin point where it is. It was so bad that the mirror was unusable. It got so bad at one point, I couldn't ride on account of the vibrations making my sphincter numb (lol).

    I looked up how to balance the crank. I was going to tear the motor apart, and just bite the bullet and balance it. I had to do what I had to do.

    I decided to order the Manic Mechanic rear sprocket adapter and a 40 tooth sprocket. MAN, what a difference it makes. Really. I barely feel anything anymore. Partly because my sphincter is probably dead by now. But mostly because the sprocket is so centered, it feels like a new bike now.

    I have to say to anyone, if you have a bike, and it has any type of vibration, get a Manic Mechanic sprocket adapter. I went down 4 teeth. The adapter was very very easy, very well made and incredibly easy to install. I wondered why they had instructions along with the kit. It even came with Allen wrenches to install it onto the bike. Plus, I ordered it Monday, was at my house on Thursday. It was the best 75$ I spent on this bike thus far. Also, my chain doesn't rub the rear tire anymore (which was another problem I had).

    Hope you guys learn from me. Don't be cheap, buy good quality products (from the guys who made them, not cheap knock offs), and your problems will diminish.
     
  2. Greg58

    Greg58 Well-Known Member

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    Don it is strange that some of these engines vibrate and some don't. I guess it the lack of quality control, it probably someone with very little training that does the balancing on the ones that vibrate.
     
  3. donphantasmo

    donphantasmo Member

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    Greg, you actually think people spend time balancing them. I personally don't. My buddy does, but he doesn't think they spend a lot of time or should I say quality time on the balancing process.
    Anyways, you're right. I truly thought the engine was the source of the vibration because the vibration went up once the throttle was pulled (not with speed). But, it's amazing how crazy it is that it has nothing to do with the engine.
     
  4. Greg58

    Greg58 Well-Known Member

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    I learner quickly if you don't have the chain aligned straight it will cause a vibration at mid throttle, another thing is over tightening the chain.
     
  5. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

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    Good to see that Manic Mechanics new owner is now selling sprockets with the adapters.
    I hope that he stays in business as we need more sources of accessories.
    http://www.mmbikeparts.com/order.htm

    PS: I have no connection to the new owner and only leave the MM link
    in the race announcements as a gesture of thanks to previous support
    from Jim.
     
  6. multipaul

    multipaul New Member

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    It's interesting to read that the balancing of the crankshaft will not be necessary if the rear sprocket is exactly centered.

    Multipaul
     
    #6 multipaul, Jun 15, 2012
    Last edited: Jun 16, 2012
  7. donphantasmo

    donphantasmo Member

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    Sorry, MultiPaul. I don't know what in the world you are talking about. You took my thread and went a totally different direction with it.

    I just wanted to let people know that the engine driven sprocket is very important to be perfectly centered. Just a minute variance will throw off your centerline and make you vibrate your sphincter loose, lol..

    And if you were to want to perfectly center it, you should trust the guys of Manic Mechanic.

    I really didn't want to bring up motorized bicycling in Germany. I LOVE Germany. I've been there, and it's one of the best countries I've ever went to in the world. With that being said, people of Deuchland should like the sprocket adapter. It centers the sprocket to an almost perfect "zero tolerance" degree. And we all know how Germans love perfection!!!

    Anywho, Cheers.

    Danke!
     
  8. killercanuck

    killercanuck New Member

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    He's talking about the difficulty of passing an engineers inspection with a manic hub adapter. You started the thread to talk about the adapter, right? :p

    I've had one crappy kit sprocket not seat the chain properly too, had to get out the dremel and "fix" it. It had really bad vibes, and felt like gravel in the wheel bearing. That'd be something to watch for too, for future readers.

    Happy cruising on your less-vibey ride :)
     
  9. multipaul

    multipaul New Member

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    You're right. Vibrations often result of errors in the chain track. And of course, from not centrally current sprockets.

    I did not want to destroy your thread and I didn`t want to annoy anyone. But I'm afraid I did a bit, because I was too licentious. I will edit my text above and... I'm sorry!

    Regards - Multipaul
     
  10. monark

    monark New Member

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    been working quite a bit with small engines (rang. from rc to 500cc) and almost everytime vibrations of this kind has something to do with drivetrain.with these small displacements the vibrations seldom gets so big and when they does the engine is about to give in so you are bound to notice,a vibrating mirror sure but im talking about those times you dont even want to start it.glad it worked out!
     
  11. donphantasmo

    donphantasmo Member

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    Multipaul, do not change anything in your reply to the thread. No problem. I just wanted to bring us back on course.

    I didn't know how hard it is to register a bike with an aftermarket hub. So, I apologize for that. I hope it works out for you, though..
     
  12. monark

    monark New Member

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    hello! sometimes when these threads get out of line you great members of this forum have to think about the other atleast 60% of us that live abroad.we seldom think in the same lines that you in e.x LA does because we just cannot "just pop down to the shop". Just recieved a B&R rod from the states, it began at retail 58$ and i paid 229,20$ for it with tax and customsfees!!!
     
  13. multipaul

    multipaul New Member

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    Don't apologize. We are adult people. Once again, it is your thread and I went off topic.
    If I could not handle criticism, I should not post in a forum.

    I miss the smileys "drinking beer" and "shaking hands". They are sozial very important and reach more than a hundred smiley with bikers.

    ;) - Multipaul
     
  14. killercanuck

    killercanuck New Member

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  15. Allen_Wrench

    Allen_Wrench Resident Mad Scientist

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    I've never used an inferior tire-rubber spoke-clamp adapter. I read a number of posts here before I built my first bike. I've used an MM hub adapter from day one. It's been one of the things about my bike that, though I've checked regularly, I've never really worried about. And I can't really complain about vibration either, although I do not use rubber motor-mounts. I bolt directly and solidly to the frame. I tend to keep my rear wheel and chain as aligned as possible. Perhaps that is why it vibrates so little, regardless of RPM. The engine, and the way the bike glides, always seem to feel "just right".
     

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