Front wheel wobble cause?

[Stu]

What can cause the front wheel to wobble IF you take your hands off the bars?

The front wheel bearings have been replaced to no avail.
Front tyre pressure is OK, tyre tread is worn & mostly on the right but I don't think it should be so bad as to cause the wobble.

Wobble happens at all speeds, so long as you're going fast enough to take both hands off the bars ad gets progressively worse until it's almost a tank slapper & you have to grab the bars again.

Bike is an 02 reg half faired Fazer.

TIA

Head bearings and tyre balance???

[Mark_h]

Often down to a dodgy tyre. Mate had it on his FJR and that's got a load of mass to wobble. Other obvious one is if it's a bike that's been laid up for a while with ultraseal or some other puncture gloop in it then it may clump somewhere. Go get it chucked on a tyre balancing thing and see if it's balanced. This should show up either an iffy tyre or gloop.

If not then it's down to head bearings, suspension and other complex stuff so start with the simple stuff.

[Biker Biggles]

Bent wheel?

[Stu]

Originally Posted by cb1000rsteve

Head bearings and tyre balance???

Be disappointed if bike shop suggested wheel bearings & it turns out to be head bearings. I thought tyre balance only showed itself at a particular speed???

Originally Posted by Mark_h

Often down to a dodgy tyre. Mate had it on his FJR and that's got a load of mass to wobble. Other obvious one is if it's a bike that's been laid up for a while with ultraseal or some other puncture gloop in it then it may clump somewhere. Go get it chucked on a tyre balancing thing and see if it's balanced. This should show up either an iffy tyre or gloop.

If not then it's down to head bearings, suspension and other complex stuff so start with the simple stuff.

Don't think ultraseal is involved - could be tyre, but a little expensive to change it & it's not the problem.
So how would suspension cause this & how would you rectify it?

Originally Posted by Biker Biggles

Bent wheel?

s'pose will look & see

Keep it coming if anyone knows more thanks

Wow, scare mongering or what

I get wheel wobble, and it only ever happens when (most common, not all causes obviously).

a) Tyre pressure is low, or
b) Tread is low. Time for a new tyre.
c) Tread has dropped as above, hence the tyre becomes slightly out of balance and needs re-doing.

I doubt its bent wheels or bearings.

[maviczap]

My old CBx550 used to do this on deceleration at about 35mph

Was worse when the front tyre was old and worn

My mate's Ducati developed a horrible front end wobble. Surprisingly, when he had the REAR tyre replaced, it went away.

[Mark_h]

Originally Posted by Stu

I thought tyre balance only showed itself at a particular speed???

Nope. Just typically worse at certain speeds when you hit the resonant frequency.

Originally Posted by Stu

Could be tyre, but a little expensive to change it & it's not the problem.

Hopefully a quick spin on the balance thing should find it unless it's something really weird in the carcase.

Originally Posted by Stu

So how would suspension cause this

Anything loose or broken could contribute

Originally Posted by Stu

& how would you rectify it?

Tighten or replace affected part

Do you know anyone accommodating with another fazer, you could quickly eliminate half the problems with a quick borrow of someone else's front wheel.

However, my mate with the FJR had it in and out the dealers trying to get it sorted and it turned out to be a tyre problem. One bit of the sidewall was stiffer or floppier than the rest and that set up the wobble. Not sure if it got picked up on the balancer though.

Wheel alignment?