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Death wobble

Discussion in 'XJ Technical Chat' started by James R Downs, Jun 11, 2020.

  1. James R Downs

    James R Downs New Member

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    I have a 1983 xj750 maxim. It was converted to a trike before I bought it. Its sitting on a 1985 Chevy s10 rear. When I get to about 24 mph, until about 30mph, it gets a terrible death wobble. I have balanced the wheel, put a new tire on it, and checked the bearings. I'm out of ideas. Any help?
     
  2. dkavanagh

    dkavanagh Well-Known Member Premium Member

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    head bearings tight enough?
     
  3. James R Downs

    James R Downs New Member

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    Yea, all the bearings are tight.
     
  4. XJ550H

    XJ550H Well-Known Member Premium Member

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    has it always done this or is it a new issue?
    balanced rear wheels?
    checked the rear wheel bearings?
    check the rear end and how it is attached . a bad swing arm can cause a death wobble.


    got a photo?

    what was used as a drive shaft
     
  5. Minimutly

    Minimutly Well-Known Member

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    IMG_2150.PNG Likely none of the above - if the head bearings are tight it's all to do with rake and trail - it's difficult to get right, most converted bikes to trikes have it. My z750 wobbled exactly like yours, when I bought it it was almost impossible to stop it. After rebuilding the whole frame, and stiffening it up considerably it still wobbled, but you could steady it with one hand. My vmax doesn't wobble at all, but it's really heavy to steer. The sweet spot is very narrow, ultimate fix is a leading link front end, but you could try lowering the front tyre pressure to almost ridiculous levels.
     

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  6. James R Downs

    James R Downs New Member

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    What do you mean by leading link front end
     
  7. XJ550H

    XJ550H Well-Known Member Premium Member

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    what he is showing in photo
     
  8. Minimutly

    Minimutly Well-Known Member

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    Do you not know google?
     
  9. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    Is that really the best way to answer an honest question?


    @James R Downs,
    A leading link front works just like a conventional swingarm that you'd find on the rear of a motorcycle, but the pivot for the swinging arm is behind the wheel. The geometry of such an arrangment makes for a very stable front-end, but at the cost of weight and some minor handling differences (which won't be noticeable on a trike).
     
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  10. Minimutly

    Minimutly Well-Known Member

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    No, it was a bit short. But google did a far better job than I could have done (I checked). Nevertheless, I have noticed that because sitting behind a keboard is easy it means people don't bother thinking for themselves, and ultimately, you know me, I love being helpful, but spoonfeeding is not my thing - life's too short.
     
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  11. James R Downs

    James R Downs New Member

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    I've done some Google searching, where would info about finding an earl fork system for my bike. I haven't been able to ride it because the wobble is literally at speed limit
     
  12. Franz

    Franz Well-Known Member

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  13. Franz

    Franz Well-Known Member

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  14. Franz

    Franz Well-Known Member

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    You are from the USA just noticed that lol.
     
  15. James R Downs

    James R Downs New Member

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    Yea, good ol us of a lol.
     
  16. James R Downs

    James R Downs New Member

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    If anyone has any sites as ti where I could order parts for this type of front end for my bike, I would be most appreciative.
     
  17. Minimutly

    Minimutly Well-Known Member

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    There you go - you taught me something - I never knew they were called Earle forks.
    No one will have these in stock - you'll have to comission someone to make a set for you, or make you own!
    One thing though - you say it wobles at the speed limit - normally trike heads woble at low speed, and it reduces as you go faster. If this isn't happening I would suggest there is something else amiss?
     
  18. XJ550H

    XJ550H Well-Known Member Premium Member

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    he should check anything and everything to do with the bike that may be loose or mis adjusted, before buying a new front end.

    still want to know if this is a new issue or he got it that way.

    how is motor connected to the rear end can we see a photo of the set up
     
    Last edited: Jun 15, 2020
  19. James R Downs

    James R Downs New Member

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    I got it this way. It's a home made trike.
     
  20. James R Downs

    James R Downs New Member

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    What about a steering damper kit?
     

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