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  • Headshakes!!!

    Hi Everyone

    I ride a very tidy 2005 Kawasaki 250 GPX and it has been a hoot to ride so far.

    A while ago i noticed that when i took my hands off the bars at around 70kmh, the head started to shake...

    So I was lucky enough to have Monday off work, took the bike to my local bike mechanic. He balanced both front and rear wheel, aligned them and then tightened the front end. Took it for a test ride, better but the front end still shakes at 70kmh. He seemed a bit out of ideas and suggested it could be the front tyre (plenty of tread, but factory tyres).

    Has anyone else experienced this or have any ideas?

    Forgive my lack of technical knowledge, trying to learn where i can.


  • #2
    Yep it could be the tyre itself. if it has been out of balance for a while it would have worn unevenly. Now even though the wheel is balanced the tyre will still have some sections worn more than others effectivly having high and low spots.


    • #3
      the front tyre could be cupping, check for uneaven wear and flat wear spots on the front tyre.

      While we're on the question of headshakes, I seem to be getting them often on my r1 under hard acceleration, i've been told its due to the front skimming the ground. whats the best way to make them stop beside wheelies? damper?


      • #4
        I'd say correct suspension set up before getting a steering damper

        Your pretty light mike so i doubt you'd need to respring or anything.

        Maybe give martymoose a PM


        • #5
          It's a GPX, there's nothing to adjust in the suspension.

          If the bike is 4 years old and still has the original tyres on it, I'd wager they're due for replacement. Maybe not worn down, but still not good for riding on.
          For LAMS information and resources -
          For LAMS discussion and to ask questions -


          • #6
            thanks for the responses...

            yeah i was kinda hoping it wouldnt be the tyre, im a cheapskate...

            someone from work told me another thing to consider is the rear swing arm... something to do with the bushes being defective or the main bolt holding the swing arm to the bike being bent.

            any thoughts?


            • #7
              Change your front tyre...


              • #8
                The fact that its shaking and your going HEY LOOK MAH, NO HANDS!

                Could end badly...


                • #9
                  4 years on stock tyres? really?

                  When I boughy my ZZR the tyres had 1.5years on them. After owning the bike for a year, the tyres had no grip what so ever, the compound had gone hard and in rain it offered to grip. (This were Dunlop arromaxes). The new Battlax offer so much more confidence.

                  So if I was you I would Change the tyres regardless, you and your riding will benefit immensely.


                  • #10
                    Originally posted by Michael/ View Post
                    The fact that its shaking and your going HEY LOOK MAH, NO HANDS!

                    Could end badly...
                    How else are you gonna check whether your bike steers straight?
                    Originally posted by Dragunov-21
                    If you want me to answer a question, I want you to ask one that doesn't put words in my mouth that were never there.


                    • #11
                      I gots me an '04 GPX and before I bought it (private) got a mate of mine to test ride it for me and he said he noticed the same thing. I can tell my bike has been dropped on the right hand side has yours been dropped hard at any point? As for the tyres they're next to new, bike has only done just over 7k.
                      I'm not too worried about it to be honest, as long as nothing is loose and steering is unaffected I think its OK, but it would be nice to know wtf is going on.

                      Originally posted by timmay
                      So UC bike spots people speeding, pulls out magnetic siren,
                      and sticks it on his head?


                      • #12
                        Fall away they calls it,
                        1. Support bike in an upright position so the front end is completely suspended & the bike is level.
                        2. place masking tape over front tyre. Tape a ruler over the tape (wish I could send pictures) Draw a line on the tape even with the centre of the ruler.
                        3. install a pointer on the floor or hang a string from above weighted and vertical. Loosen lower fork stem bolts (triple tree bolts)
                        4. Tap the tyre slowly left and record the distace travled before it swings down by itself, record mark on the ruler. Do the same for the other side.
                        5.Subtract one number from the other. The distance between the fall away marks should be between 51 - 102mm. Find a workshop manualfor more details. loosen triple tree top & nut. tighten (most likely the steering head bearings.WHEN IS THE TUNING DAY ???
                        Last edited by Sooty; 18-10-2009, 08:38 AM. Reason: spacing


                        Another perfect day in paradise.


                        • #13
                          Originally posted by barfridge View Post
                          It's a GPX, there's nothing to adjust in the suspension.
                          Slightly off topic, but in fact you can adjust the suspension on a GPX/ZZR suspension.

                          You can increase the damping by using a different weight fork oil - you'd typically put a heavier weight (thicker) oil in - this is very effective in improving the performance of the front end!

                          And you can also increase the amount of preload on the front springs, by removing the bars, taking the cap of the top of each fork and placing a special spacer (exactly the same size as a 20c piece, hint hint) between the stock tubular spacer and the cap. 1-2 coins per fork makes a night and day difference - totally worth doing if you weigh more than 50kg.

                          This also works on other bikes that have no adjustments, although if they have larger forks than the average 250cc forks you may need to find a different spacer.


                          • #14
                            Hi sooty

                            I bought a manual the other day so i will have a look.

                            Worse come to worse, would a six pack cover a tuition fee?!?!?


                            • #15
                              i dont know much about bikes and all but my old zzr did the same thing as well, quite the shaker, i went in and they said it was the steering bearings... they replaced em and it was all good after that