sprocket wobble

Discussion in 'Motorized Bicycle General Discussion' started by brucemg51, Aug 13, 2008.

  1. brucemg51

    brucemg51 New Member

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    I've just installed the rear sprocket, along with the two binders and backing plate. I can't seem to get the sprocket to stop wobbling. All nine of the bolts are as tight as I can make them. I tried loosening the bolts a little on one side, but that didn't help. Any suggestions[​IMG]
     
    #1 brucemg51, Aug 13, 2008
    Last edited: Aug 17, 2008
  2. NunyaBidness

    NunyaBidness Active Member

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    don't make the bolts too tight, let them be a little loose. then just try to true it by adjusting the bolts as needed to reduce the wobble. that's what helped me.
     
  3. brucemg51

    brucemg51 New Member

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    But then, aren't the bolts going to loosen up when you start riding?
     
  4. stude13

    stude13 New Member

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    use nylock nuts
     
  5. pedalpower

    pedalpower New Member

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    don't know if it stops the wobble but I don't have any. I think it's because I installed 2 sets of backing plates. the first is the set that has 2 pieces and the second is the set of 3 pieces that staggers the seams like brickwork. I noticed before that the plates will bend a little when you tighten them down. worked for me. jon
     
  6. brucemg51

    brucemg51 New Member

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    What about threadlock or locktite or something like that?
     
  7. stude13

    stude13 New Member

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    nylock nuts lock themselves with nylon
     
  8. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    Torque the bolts slowly in a "star" pattern... Don't worry about getting the bolts as tight as you can!!! Worry more about slowly tightening the bolts, & getting the sprocket to spin straight! Don't over torque!
     
  9. brucemg51

    brucemg51 New Member

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    I've definitely overtorqued. I'll back up and do it over.
     
  10. BlueCollarBike

    BlueCollarBike New Member

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    Very good advice.:)

    loosen all the bolts a little

    spin the tire/sprocket and slowly bring a piece of chalk ( or Marker) close to the top of the sprocket .
    It will leave a mark at the high point.
    Tighten the high point more then the low.
    Also if your unable to get the sprocket to stop wobbling ...

    take a block of wood and wack the high point with a hammer .It may sound barbaric but it works.

    hope this helps.

    Cheers:)

    Bob
    Home
     
  11. brucemg51

    brucemg51 New Member

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    Thanks Bob,
    What I did was to shim one side with a piece of inner tube and that helped. It still ain't perfect, but what is?
     
  12. NunyaBidness

    NunyaBidness Active Member

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    after I last got my 41 chain on, the sprocket was still wanting to let the chain off. I walked up and down my driveway with the clutch in and each time the chain wanted to jump off the sprocket, I tapped the sprocket with a hammer. I kept doing that until it no longer was trying to come off the sprocket, I rode a bit with out the motor and it stayed on fine so I fired it up and it hasn't been a problem since.
     
  13. Frantic Fabricator

    Frantic Fabricator New Member

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    I just finished my first build around 1 month ago. Truing the sprocket was by far the most confusing and difficult part for me. I just eyeballed it and it runs fine. I have adjusted it here and there since then, but I wouldn't stress out about it too much unless it is visibly way off.
     
  14. BlueCollarBike

    BlueCollarBike New Member

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    I feel Truing up the Rear drive sprocket is extremely important .
    extra time and dedication Should not be spared ,
    Not just for performance but for safety Reasons as well

    Cheers:)

    Bob

    BlueCollarBike
     
  15. Frantic Fabricator

    Frantic Fabricator New Member

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    Sorry about that, didn't mean to give anyone the wrong idea. I spun the wheel for a long time and tried to get it as true as I could, but I had a hard time finding a really accurate way to measure it. I guess I'll go back and do the chalk method mentioned earlier. For some reason I had a hard time finding any info on a good way to measure when I was putting the kit on.
     
  16. pedalpower

    pedalpower New Member

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    hear me now and hear me later, ha. I have installed my sprocket and locked it down (centered that hole on the sprocket with the axle) only to see my chain tighten and loosen as it ride. ugh. read my previous post. you can use a combination of methods but the final test is its behavior on the chain so why would you commit an hour of labor before you were sure of equal chain tension. I love my fixed gears and I hate the rollout on cheap chain/cranksets. Also, this is so much easier if you have a parktool bike stand, duh. a quiet taunt chain at 25mph is heaven.
     
  17. Radmanfly

    Radmanfly New Member

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    I'm having the same problem:
    New installation on a Huffy Beach Cruiser.
    I didn't get any instructions with my kit regarding the sprocket, so I went ahead and cut a slice through one rubber spacer to allow it to go inside the spokes and sandwiched the spokes. I faced the bolts in toward the hub and tightened in a star pattern (backing plates installed inside of course) watching the center to make sure it stayed in the middle as I went. (The sprocket doesn't drop onto the hub, it just sits on the end of it, but you can see that it's fairly well centered.) Once it started to move off center, as the bolts were getting tight, I loosened that bolt back up and tightened the three opposite it. At a certain point the sprocket would just go off center in the direction of the bolt I was tightening, I had to go in 1/4 turns in a star pattern from there to keep in lined up. And I still don't have it too tight because I got to a point where it wanted to shift and I couldn't adjust it back, so I left it a little loose. It's straight but I am considering taking it off and filing the center out enlarging it to fit the hub better. Meanwhile, to test fit everything, I put it all together (I haven't tried it out yet, just got it together today) But the problem is, the chain is rubbing on my wide beach cruiser tires, so it turns out, if I had filed the center, it would only make the sprocket closer to the tire and the chain rub worse. I think I can turn the sprocket around so the high side is outside once I file it to fit the hub and hopefully this will happen to be the right distance away from the frame so it doesn't rub, while leaving the correct amount of tire clearance. I am hoping there is a better way than hit and miss here but I suspect not. Pics attached -Scott
     

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    #17 Radmanfly, Aug 15, 2008
    Last edited: Aug 15, 2008
  18. Nomad

    Nomad New Member

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    Now I like that method, sometimes a little Brutalo straightens stuff out.. :)
     
  19. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    I use a hard plastic head hammer to tap it into place while the bolts are still loose.
    Then tighten them a little more & recheck... & tighten a little more & recheck...&............ you get the picture. (^)
     
  20. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    A couple of things here that I'd like to add-

    1.) A lot of these sprockets have the center hole drilled of center, ALWAYS check it before doing anything else.
    2.) If your chain rubs your tire lightly, you'd be better off learning to live with it than to turn the sprocket around and run the sprocket(s)/chain out of alignment.

    It's important to have both sprockets and the chain all in line with each other. Moreso than keeping the whitewalls clean.

    1/2-3/4" of free play at the TIGHTEST, and at the tightest place in the run. (turn the wheel while checking tension, when/if you find a "tight spot", adjust your freeplay with the chain there).

    A chain that is run too tight causes rapid wear to the chain, tensioner wheel, and sprockets and in more extreme cases the bearings in both the rear wheel and the sprocket shaft bearings.
     
    #20 Bikeguy Joe, Aug 15, 2008
    Last edited: Aug 15, 2008

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