Movement in handlebars

Hi all and thank in advance for reading my thread.
For those who have seen my introduction to the group you will know that i have recently passed my bike test and bought a st1300a.
Just a quick question, How much movement shoud the pan have in the handle bars, i beleive they have rubber dampners mounting them but not sure if mine are excessively worn or not as there seems to be quite a lot of movement.
Reason i am asking is, i have been out on the bike in quite a strong crosswinds, while riding even at low speeds i.e 30mph the rear end felt like it was fish tailing quite violent.
Although it only done it real bad the once, i have noticed it the odd time or 2.

My father who has been riding for many years took it for a little test ride to see if he felt what i was talking about, although it never done the fishtailing he did manage to make it do it by a slight shimmer on the handle bars, i,e although you was riding it with the slight shakes. (and i mean very very slight)
I then went back out on it with him following to see if i could replicate it by giving the handlebars a very slight wiggle while doing aprox 30mph, sure enough it did exacly what i was complaining about, but the bonus was that as my dad followed he could see how the back end was behaving. He was shocked with the ammount of fish tailing it did and said it looked like if i was to do it a tad more it would have chucked me off.

Any ideas ?

As although i am a new rider i would like to think i am fairly relaxed with regards to my grip on the hande bars.

I wasnt sure wheather the wind may have been buffeting on my front wheel which created the same effect

Davrus, it could be a number of things causing your fishtailing that you felt. Tire pressures, tire make, head bearings etc. It would be useful for the more knowledgeable folks on this forum to know what mileage is on your pan, that could help narrow down some of the causes. A lot of members, myself included, have had issues with Dunlop Roadsmart tires causing a feeling of snaking or wiggling but that is more at highway/motorway speeds around 60-80MPH than what you felt at 30MPH. Changing the tires to another brand fixes that issue. Looks like that particular model of Dunlop is less suited to the ST1300 than others, at least for some of us, not all.

My bike has 67K on it and the first time i moved the handle bars up and down was a little disconcerting to say the least but it doesn't cause me an issue that i've been able to detect.

Do you have an '05 ?? What does your front end sag measure ? Cat'

The play in the handle bars should be very slight. Maybe .25" or less? I doubt that's the cause of your fishtailing. I characterize my handlebar movement as being very slight back and forth not up or down. That sounds excessive but it's hard to say if it is.

Take a walk around the bike you and Dad look for loose units— fork leg pinch bolts steering head bearings rear shock mounts swing arm etc. Are your tires in good shape? Any signs of tread damage? Can you move the rear tire side to side?

Inducing actual fishtailing (the back tire losing traction) without using the brakes sounds pretty severe to me. Is that what's happening or is it a severe weaving motion?

A new to you bike with 67K on the clock should probably get a good going over anyway but you need to get the stability sorted. Did you get any maintenance records or information when you got the bike?

If you could post some YouTube video that would help the guys who actually know what they're talking about.

Check the preload adjuster, then wheel bearings, then steering head bearings.

Just wondering if davrus's handling issues are the same as those described as "pan-weave" ?? Fortunately,, I have never experienced it. But I have read a lot on the subject, and it always struck me as the cumulative effect of many contributing factors,,, some of which have been mentioned in this thread. Cat'

Thanks for the replys.
It is on an 02 plate with 25000 mls, just passed its mot, tyres are michelins that have only covered 2000 miles so still in very good order, tyre pressues set to 42 front and rear.
I have check for any thing loose but all seems good, preload adjuster has oil in it an resistance after 2 clicks, i set it to 7 click which made no difference so added 2 more clicks at a time untill i got to about 20 then set the rear sag to 35mm while wearing my riding gear which put it back to 7 clicks and on the standard line, all preload setting make no difference to the issue.
With bike on centre stand, no movement or free play detected in rear wheel or swing arm etc.
I will check the front end sag over the week end, but like i say i must have nearly 8mm of movement in my handle bars, the movement is not in the forks, purely in the handle bar fixings them self.

As stated also check the front tire for movement back and forth when on the center stand. An forward/back. You didn't mention if you've done that.
Handlebar movement is which way? forward and back? up/down? side to side? or like some slop in the handlebars when turning them?

Be careful riding that thing until this gets sorted. what you describe and what your Dad said he saw is not normal.

Think it may be easier to post a video, will try and get one over the weekend, the movement itself is if i push and pull on the handle bars while sat on the bike, it is literallyfeels like the handle bars are fixed on rubber mounts.
I have not checked the fork bearing, how would i test them?

Videos are good. If you could straddle the front wheel and hold it tight while twisting the handlebars left to right etc you might be able to tell if any of the pinch bolts are loose. Have someone watch the upper mounting plate for relative movement and not the rubber mounted handle bars. Otherwise you could check all the bolts.

Put the bike on the center stand and jack up the front end. If you push-pull the front wheel from the front you shouldn't get any movement. I used to sit on a bike and rock it back and forth with the front brake on. Looking at the nut on top of the steering stem I could tell if there was play in the bearings. Ah the good ol' days.

While the front end is off the ground you can turn the wheel left to right etc and feel for any 'notchiness' or roughness especially as you steer passed straight ahead in either direction. That would indicate worn bearings and/or races. Doing this for my old 740-4 I found the lower inner race cracked and the upper outer race dimpled.

.... some good suggestions.

Or, you could find another ST1300 to compare with.