front end wobble

Discussion in 'Technical' started by KZ25, Jul 14, 2013.

  1. KZ25

    KZ25 Ol'Timer

    I've noticed the front wheel "feeling funny" and thought it's low air pressure. But after filling the tire it still felt a bit unusual. Took the hands away from the handle bar at 70km/h and it slowly started wobbling from left to right, quickly accelerating and getting stronger so I had to grab the bars again. It's going straight, doesn't pull to the side, but starts shaking. Never had an accident; tires are in good shape.
    It doesn't feel too bad when I'm riding normally but of course I want to know what the cause is. Mileage is almost 30,000km, bike is five years old.
    Any ideas what may cause the front end to wobble?
     
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  3. hawaiianbrians

    hawaiianbrians Ol'Timer

    Simple things first, I take it no load, just rider right? Mileage is low for steering head bearings to go out but that would be my next guess followed by swingarm bearing as a second bet. Any service done lately, ie: anything to do with changing tires, improper torque would be another option. Those would be my guesses unless you were carrying 100 kilos of bricks in your top box! Good luck, hope you get it sorted out...Brian
     
  4. monsterman

    monsterman Ol'Timer

    Loose head bearings or worn ....best to check get bike up front wheel off floor , pull forks back and forward and feel for steering stem play .
     
  5. KZ25

    KZ25 Ol'Timer

    Nothing has been done to the bike lately, that's why I thought it's tire pressure. Checked the steering head, no movement there. Guess I'll take it to the shop, see what the guys say.
     
  6. KZ25

    KZ25 Ol'Timer

    Went to a shop and the mechanic inspected the front end, no problem there. He then proceeded to take off the plastics and loosened the steering head nut with a hammer and screw driver after an attempt with a hook spanner failed. Why he didn't hit the spanner with the hammer I don't know. Then he loosened the second one underneath and tightened them up again. The forks looked okay, no oil on them.
    The wobble is still there at 60+ km/h; now the bike feels weird in slow speed turns. Not an improvement!
    It's no big deal as long as I keep my hands on the bars. But knowing that there's something off is not comforting.
    If the front tire wouldn't be in good condition I'd change it, maybe that's where the problem lies.
     
  7. JAGI00

    JAGI00 Active Member

    I had a similar problem some years ago with steering wobble on my car - checked everything and found nothing wrong. The tyres looked OK but eventually the garage mechanic convinced me that was where the problem lay. Changed them and problem gone!
     
  8. monsterman

    monsterman Ol'Timer

    Stiction in the forks , worn bushes ,, but tyre are strange things they can look good but still perform bad
     
  9. crowster69

    crowster69 Active Member

    I would next be looking at a tyre change and a wheel balance if you think your stem bearings are good and torqued up properly.
     
  10. KZ25

    KZ25 Ol'Timer

    Yes, I'll spoon on a new tire at the next oil change and have the feeling that it will do the trick!

    Like batteries, sometimes you spring for a new one and seemingly non-connected problems disappear.
     
  11. Vic Alborn

    Vic Alborn Ol'Timer

    I would suggest that the mechanic has stuffed up and has over-torqued the head bearings as you now have two problems: head shake at 60kph and stiff bearings giving you weird low speed turns. The head bearings need to be re-torqued but by a competent mechanic. As for the head shake I can't offer much more than what has already been said. Are you sure this is a new problem or have you just noticed it? Have you hit any holes in the road lately, or kerbs? Is the front wheel "round"? (Run true at the rim when spun up?) Sorry if this sounds a bit trite but sometimes the most obvious are over-looked? Keep us posted as the eventual solution will help us all. Cheers
     
  12. KZ25

    KZ25 Ol'Timer

    I've just recently noticed it so I don't know if it is a new problem. Don't think so because there were no impacts of any kind and the front mag is straight, not bent, and with the fork lifted up there's no problem with the steering head.
    It is only a small problem, as long as I keep my hands on the grips I can't feel it and the slow speed cornering has gotten better somehow but knowing that something is not 100% doesn't make me happy. I'm not a perfectionist but when it comes to my ride I need to know that everything is as it should be.
    I'm fairly sure it's the front tire, it looks alright, has lots of thread left and is only a year old (I make sure when I get a tire that it's a recent one).
    Today I pushed the bike slowly in a parking garage and the front wheel felt a tiny bit "knobby" as if I'm pushing an enduro. I checked and felt the surface of the tire, found nothing, but pushing it feels like the tire has small blisters. I always run the right pressure so it's not that.
    I'm fairly sure a new tire will take care of the problem and will get one soon.
     
  13. jimbobs

    jimbobs Ol'Timer

    I learn something new everyday off you guys,,,,,,I have felt a wobble,,,I had it checked out

    my front wheel was not tightened up,,,,I have ridden it thinking it is nothing

    i really am a man who has ridden bikes for years and not questioned things,,,

    could have been quite hairy

    thanks
     
  14. Linds

    Linds Ol'Timer

    Have you checked your discs?
    what bike are you on about?
    if your on mag wheels then evan a small crack you would not see with your eye,but you would feel it on your ride.
    Rim true is also important ,both sideways and up and down as is correct balancing ,,,as you know already

    As above torque wrenches are not used here as should be,also torqued nuts an bolts should be replaced if done too many times

    Tank slappers are bad so are busted wheels at speed no matter what you ride......

    hope u accept the input
    Regards
    linds
     
  15. Vic Alborn

    Vic Alborn Ol'Timer

    OK. The steering head bearings have probably settled in a bit since the re-torque. One more thing comes to mind (in view of the above quote) if a new tyre does not improve things, check the front wheel bearings. Cheers.
     
  16. DavidFL

    DavidFL Administrator Staff Member

    I'd go for the steering head bearings. New ones should only be a couple of hundred baht I think.
    How old are your tyres?
     
  17. NickyBKK

    NickyBKK Ol'Timer

    I had the same issue (or similar) with my Ninja 250 a few years back. It happened after I changed the front tire from stock to a Pirelli :crazy: . After I balanced the tire again the problem was less but still there.
     
  18. Vic Alborn

    Vic Alborn Ol'Timer

    Have you tried any of the suggested fixes or found the cause?
     
  19. KZ25

    KZ25 Ol'Timer

    I've replaced the tire and things have improved. Not 100% but it seems like the tire was the culprit. Maybe messing with the steering head was a mistake.
    The tire was only one year old, had lots of profile left and showed no cracks. But something must have been wrong after only a few thousand km.
     
  20. Franz

    Franz Ol'Timer

    Sorry Klaus that I reply soooo late but had the same problem with my Nouvo 135 Elegance. During my time in the Hospital had my partner bring the scoot to Yamaha Square and get rid of the pompemm. First some Somchai's tested and said no pompemm, then I asked Daen the Yamaha big bike mechanic to have a look. Frontforks were slightly out of center, triple tree had hair cracks and all bearings//sealrings have also been replaced by him with the result that the wobble is gone. As a precaution also changed the tubeless IRC tyre with the same make and model but before the tyre change a friend tested the scoot and said now you can ride it 'free handed'........Total costs were slightly above 4,500 THB but must admit Daen did a very good job. This all because I had this nasty crash earlier this year at around 90 km/h. Hope this still helps; get yourself new front forks and a new triple tree for holding them in place. All bearings you can usually get at any shop with SKF or NTN logos. Rgds, Franz
     

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