Higher Speed Wobble Problems

Discussion in 'Dyna Models' started by texasdynaryder, Oct 6, 2009.

  1. texasdynaryder

    texasdynaryder Member

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    im am owner of a 07 dyna street bob. this is my second bike and i love upgrades and looking diff. but...
    6 months ago i installed an Accutronix Wide Glide Conversion kit with a 3 degree built in rake... nothing fancy had those powder cated.. had both wheels torn down ( to have hubs and rims powder coated) and relaced. an 1inch lowering kit in the back to bring the trail and drag back to normal. once back together it has an awful wobble above 65 to 75 MPH. the bike has been in 2 seperate HD dealerships where nothing could be found wrong. and its 10 k service. if anybody has as suggestions i am ALL ears. thanks
     
  2. Hoople

    Hoople Account Removed

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    Tex,
    Do you still have the same stock tire sizes on the Bike. If not what sizes are they.

    From where I am it Sounds like you have a Dynamic imbalance (2 Plane imbalance) in one of the tires. This type of imbalance can Not be detected in a simple bubble balance procedure. Suspending the tire on a knife edge and finding the heavy point by gravity will NOT correct a 2 plane dynamic imbalance.

    A rotating mass that has a static imbalance (bubble balance) will have a "Tramp" or a vertical up-down imbalance. A rotating mass that has a dynamic 2 plane imbalance will have a "Wiggle" or a dynamic imbalance.

    What size rear tire are you running. Did you make ALL the modes at the same time.
    I certainly can be wrong but if I was to have only 1 guess as to what it was, without seeing the bike & without being able to test a few things or ride it, I would say it is a problem in the re-lacing of 1 of the wheels. The reason I say this is because a 2 plane imbalance will manifest itself at a specific resonant frequency (narrow band of RPM or MPH) which is exactly what you have.

    Hoop!
     
  3. springer03

    springer03 Active Member

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    really sounds like front to rear alignment.. Low speeds you compensate. Tires will probably wear on one side.
     
  4. texasdynaryder

    texasdynaryder Member

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    they should be stock size Metzler Me 880 but will check for sure when at hope.... as far as alignment. they seem to be wearing pretty evenly?!? and yes all MODs were at the same time.
     
    Last edited: Oct 6, 2009
  5. texasdynaryder

    texasdynaryder Member

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    Front tire is a 100-90-19 57h
    Rear tire is a 190-70-b17 73h
    both of which are tubeless. now another question of mine would be can a spoke rim be
    balanced and still be untrue? or if thats even possible. gonna try and get some pictures posted today of other possble questions.
     
  6. Hoople

    Hoople Account Removed

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    Absolutely. You can bubble balance a tire and rim that was in the shape of an Egg. The balancer is blind and is only telling you where the heavy spot is.

    This is Especially true if you only Static (knife edge/bubble balance) balanced your rims/tires.

    What I would do is lift the bike so both wheels are off the ground. Rig up a fixed metal pointer to you can check BOTH vertical and lateral run out. Of course it is only a rough check but you at least will see a bad case of run-out which you could easily have.

    Hoop!

    Not that it has anything to do with your problem... I though all laced rims needed Tubes. ?? I did not know you could have adjustable spokes and be tubeless.

    Hoop!
     
    Last edited by a moderator: Oct 7, 2009
  7. texasdynaryder

    texasdynaryder Member

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    I also thought the same also! if u get time check the pictures that were just uplaoded and check out the front end. the kit came with an aftermarket axle. if looking in the dyna service manual it requires a 7/16 drill bit to fit through the axle tension hole. then butted up against the lower fok tube. my after market axle still has probably near a 1/4 inch to go... and as far as the front rim goes to be centered within the forks. is there any off-set in the front rim?
     
  8. Hoople

    Hoople Account Removed

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    My guess is you must have Tubeless tires with tubes in them. There is nothing wrong with that..

    Don't see any uploaded pictures..

    Hoop!
     
  9. texasdynaryder

    texasdynaryder Member

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    they are on my profile
     
  10. Hoople

    Hoople Account Removed

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    You took this bike to 2 different dealers and they think that offset is OK.?
    I am amazed you can ride this bike at all.

    Disregard everything I said about dynamic imbalance. Springer03 was right from the get go.