Death Wobbles

[MrWasabi]

I haven’t been on my bike much since the last Friday putty loop run. Maybe once or twice, but today on my way to work, I noticed that when I let go of the handle bars, they started to shake slowly. The shakes progressively got bigger and bigger. I didn’t let it get big enough to actually put me in any danger, but I have never noticed the bike do this before. It would only happen if I was travelling any faster than 60.

I don’t usually let go of the bars, so I don’t know if this has been happening for a long time, or if its normal.

Any ideas what it could be?

[Wattie]

what tyre on the front??

i found that bridgestone bt014's always wobbled a little bit.


also when i tyre is nearly rooted it will start to wobble.


possibly check your headstem bearings too

[MrWasabi]

im sure the front is bridgestone, but not sure if its a bt...
will check on my lunch break.
dont think the tyre is too bad, there is plenty of tread left on it

headstem bearings, i presume are the same as steering column bearings? if so i replaced them when i got the bike.

[ducati_paul]

Yeah I was the same on my Ducati for a while until I put a new Tyre on the front then it was instantly cured, I just thought they all did it when worn but now that you mention it I think mine was a BT 014 too Great tyre though! (when they are aren't worn out!)

[robracer]

im sure the front is bridgestone, but not sure if its a bt...
will check on my lunch break.
dont think the tyre is too bad, there is plenty of tread left on it

headstem bearings, i presume are the same as steering column bearings? if so i replaced them when i got the bike.

with the steering head bearings check to see if there is any sideways movement which would mean having to tighten the main nut, you want a very very slight binding as you turn the bars... & no sideways play at all & not loose so that the bars slop from side to side.

The tyre can have lots of tread left but start to feather if the tyres are out of alignment & the true alignment can only be done via string line or a newer invention laser alignment, for me its the string anyday forget the side plates on the adjusters as they are never correct.

so I would suggest it may be one of these or both......... steering head bearings or tyre alignment / wear.
give us a yell if you need help to do either.

[SoundGuy]

Yep i think its your steering head bearing dude.

[JetPilot]

Possibly front tyre out of balance. Just a thought.

[98ninja]

dont let go of the bars...........

[MrWasabi]

dont let go of the bars...........

yeah thats an option

Ive checked and the front is a Bridgestone Batlaxe BT45F
Also checked for what you said rob and there is no play in the steering head bearing that i can notice. Bars are solid, they are left where i place them if i have the bike on its center stand and i put weight on the rear.
so they dont flop down.

how bad would it be to keep riding with this issue? might look at a new tyre next month, but the weather looks good this weekend and i was going to come to the PITS, as i havent been in a while.

[Six Addict]

my dads old beemer get head shakes.... he has a big knob on the steering haed that can tighten and loosen the streering head.... so he can just tighten it when the bike is stopped... no such luxury on modern bikes...

[6maniac]

Also - excess weight behind the rear axle will give the same effect .

[98ninja]

my zzr250 had wicked headshake with no hands on the bars. i took it as the weight of the bike coupled with the not so great suspension (91 model).
next bike a c model zx9r never had such problem. the 12 i have now had bad headshake with no hands on the bars until i wound the preload on and now its as good as the zx9r.

[timmyrocks]

if you changed the bearings when u got the bike have you checked the prelead on them?
the bearings in your steering head are taper locks (car wheel bearings) and after a while of running in they will need to nut tightned again to "preload" the bearings again as the break in initially and will apear to be loose but thats just them bedding in
try this, if that dun help check if your wheel striaght, forks are tight and wheels on tight.
if none of the above then yeh maby the wheel
lolz
cheers Tim

[jl4049]

I get the same on my 9 with a rooted front tyre, with both michelin tyre and bridgestones. Haven'tgot it yet with the pirelli supercorsas, but there is still alot of life left in the front one.

[Smitty]

dont let go of the bars...........

yeah thats an option

Ive checked and the front is a Bridgestone Batlaxe BT45F
.

BT45s scallop out because of road camber (they have soft sides)

I used to get this on the Gpx...and after a quick check of wheel and steering bearings
I would suggest a new front tyre (it always fixed it for me)


hth

Smitty