Topic: Wobble at speed

[anparkinson]

If I take my hands off my bars on my 550K3 at between 40 - 50 mph the bars start wobbling until it wants to tank slap.

I have checked the wheel alignment, had both wheels rebalanced, checked and adjusted headstock bearings, checked tyre pressures but no difference.

My friend's identical K3 doesn't do it so it is a problem with mine.

Any ideas (apart from not letting go of the bars)

[flybox1]

did you do all of this ^^^^ to the rear as well?

rear swing arm bushings?
did you replace wheel bearings in both wheels?
are the wheels our of round?
front fork service/rebuild?

[mono]

mine does the same thing at 40-50, then smooths out again at +50 MPH.  i just go slow or go fast.  *shrug*  also, i highly recommend keeping your hands on the bars.   

[killersoundz]

'checked and adjusted headstock bearings'

Did you raise the front end off the ground and check for a notch? That's likely the cause IMO. If this starts to happen one thing that can keep the bike stable is shift your weight forward by sliding up far on the seat.

[NewOldSchool]

Mine used to do that when my REAR tire was fairly worn out. Got a new front and rear + had them balanced and its rock steady now.

[anparkinson]

rear swing arm bushings good -  no play and greased

did you replace wheel bearings in both wheels? -  No.  Still on originals at 23,000 miles. No play and smooth.

are the wheels our of round? Will check

front fork service/rebuild? -  yes.  About 4,000 miles ago.  Fresh oil last year.

Alignment front and rear done.

Tyres quite new

No notch on headstock bearings

[brooze72]

Are you running with a fork brace or fender? Matched tires? Double check alignment with a straight edge? Change the headstock bearings anyways, IMO. Or steal your friend's K3 & replace it with yours