wobbly speed wobblings....

[ElkWorks]

Has anyone had this problem with their fazer?

Typically, I use the bike for commuting 70 miles a day, and it sits on the motorway around 65-70mph.

Yesterday I took it out with some friends for a spirited ride…

However, when exceeding 70mph (on a private road) the bike starts to shake, a lot. At 80mph and above it just feels like its gonna chuck itself over. This is in a straight line. During cornering it felt worse, and my mate commented it looked like it was buckarooing…

Tyre is only 3k old, and was balanced when put on
Tyre pressures are fine
Head bearings seems fine from the side to side trick, not front to back play either.
Bars are raask jotas (with a much wider spacing which in theory should hold the bike more stable from rider input) , but it also did this on the stock bars.
Wheel axle, is tight, all yoke bolts tight
Brakes aren’t interfering, and the discs aren’t warped, it brakes smoothly from that speed also.
Tyre wont have gone out of round either as its left on centre stand at night and covers at least 250 miles a week., it also wont have slipped on the rim, as it’s the front, or maybe the back on has?!



Wtf? I don’t remember it doing this before, but then again, ive always really only used it for commuting as I have other bikes to be silly on.

Wheel bearings?
Suspension fooked? Ive got a 98 mode, so cant adjust anything.

[noggythenog]

I dont really know what the engine mounts are like on these...ive never actually looked for them but has it either had the engine out or had a replacement engine & maybe the mounts are iffy or is there mounting bushes that are maybe focced and the engine is vibrating about in the frame....surely it would wobble about on the centre stand at high revs if that was the case though....just throwing it out there.




Anyway i cant see how that would cause buckarooing.






As a complete novice i would guess more likely the rear wheel bearing but wouldnt you get a whining from that at speed or knocking when you pull away?.






As always i look forward to hearing what the pro's think.




One of these days ill guess something right

[Ruby Racing]

Tyres would be my first thought. 3K miles is a fair bit.


However I'd be tempted to say perhaps one of your wheel weights has come off, or the wheels were not balanced correctly in the first place. Or they may be the weights that were fitted for your previous tyre. I get around this by taking off the wheel weights when getting my tyres fitted. Also helps stop your rims getting scratched by some neanderthal prising off the old wheel weights with a screwdriver!


The front is more sensitive than the rear, however I would get them both rechecked for balance if I were you. The symptoms sound the as when I once had a wheel not balanced correctly. If you don't usually exceed 70mph then maybe the problem hasn't shown itself before, because it only happens when you go faster.


Wheels bearings is another possibility.


Get them rebalanced, that would be the cheapest option I think.

[Fazerider]

Swingarm pivot bearings?
Excess play in the rear suspension linkage?

[darrsi]

Uneven fork oil levels could possibly cause front end wobbles as well.

[unfazed]

Your first check should be the wheel bearings and then the wheel balance. Front wheel first and then the rear wheel. Take off the calipers before you check the wheel bearings, you cannot check wheel bearings properly with the calipers on and then take of the wheel to check the balance
Check the rear shock and linkage bearings and finally check the Swinging arm bearings.
Wheels can go out of balance from numerous things like hitting potholes, hitting speed ramps or losing a wheel weight.