Stability question

I road my 03 st1300 quickly up to 90 mph on the interstate into a headwind with the windshield all the way up.
my original tires have 3400 miles on them and my bike was extremely twitchy, it wanted to wiggle badly. Very badly, my question is , is that the handiling trait that I read about? At 80 it did not do it. Thank you dave

I can't comment because I drop my windshield considerably for higher speeds....however....as you mentioned in a previous post....your tires are extremely old and should be replaced.

Re: Suggestions needed

The windscreen shouldn't be part of the equation, altho the wind on the screen tends to "lighten" the front end. I would check to see if a previous owner altered the ride height. If the rear shock was lowered for a short legged rider it throws more of the weight to the rear and makes the bike want to go into a tankslapper. The higher the speed the worse the effect. I have found that changing the rear ride height by as little as 1/2 inch can tremendously affect the front end stability. Aftermarket suspension can do this if the ride height was not carefully set. So will a really fat pillion rider

Pico,,, what was on the back of your bike,, when you ran it up to 90 ?? ie: an oem or givi style rear case ?? Cat'

If you are saying your tyres are 14 years old then it's time to change.
Check what other 13 riders recommend for a stable ride. I like Bridgestone's on my 11.
BUT, all bikes wobble and weave, slow speed wobble felt through the bars and high speed weave. Loading, tyres, pressures, speed, wind flow etc will all upset the handling to a degree.
There is an interesting video on the net, it's ancient but very relevant, search on Wobble and Weave, Dunlop, Murray Walker. It's a must watch.
Hope it helps.
Upt'North.

Earl43P said:

change brake and clutch fluid if looks dirty.

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Brake fluid (goes in the clutch too) is hydroscopic. Even if it is clear, it might have absorbed enough moisture over the years to start corrosion inside the brake system. Honda recommends changing it every two years (cooling system juice, too) and some guys here change the brake fluid every year. Were this my bike, absent maintenance records, I would change ALL fluids after this time, tires, and regoop (technical term) the splines in the rear wheel. I'd also go over the whole bike checking everything.

I refilled my rear preload adjuster a couple of years ago and played with the rear shock rebound adjustment (if it ain't broke, make it so). When I took the bike out in the spring, I found it unstable at speed in turbulence behind semi's. You might check those two items and adjust both to Honda's recommendations. I run Pirelli Angel GT's and love them, after reading Larry's (Igofar) review.

I just changed my fork oil and reduced the sag (or rather I watched and handed Ray the tools). I can honestly say that the improvement in handling is remarkable. The most obvious symptom before was the 'dance' that would happen with shield up in dirty air (passing a transport). IMO checking the front end sag should be on your list. Relatively easy to check and non invasive.

Picopower said:

...my original tires have 3400 miles on them...

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Please tell me you're not riding around on 14-year-old tires.

--Mark

Yes I'm using these tires up, fluids all changed at required times over the years. Givi was not on. She's a squirmy girl at speed.
im sure the tires have a lot to do with it. I don't believe it's been lowered. Cause I've got a 32 Inseam and I'm on tippy toes at stop.
but it's sad that I can't ride it to 140. Just kidding 80 is fast enough for me. Thanks for all tips. Will use good information.

For what it's worth my Tiger 955i also tended to weave at speeds over 80 mph when carrying the panniers and top box. I increased the pre-load to compensate for the weight of the luggage (empty I'd estimate they weigh about 25lbs) and changed my riding position to put more weight on the bars. This cured any instability. I can run to 110mph without an issue now.
That said, the owners manual warns about instability with the luggage on at speeds over 80 mph. I suspected that was due to the effect of the bags on the aerodynamics of the bike.

My 04 was tested WAY over that for scientific purposes. Set your rear rebound screw at the point where your rebound doesn't take forever to find static sag and doesn't rebound too quickly and oscillate. This setting tames the mass of the swing arm/tire etc. not dependent on load. You might also check the preload knob for range of adjustment it might need fluid if you have a ton of turns with no resistance.

If you mean you have original '03 tires with tread left, PLEASE do not ride it until you get tires they're not just hard and out of round. Setting up sag/preload is not your biggest problem.

I disagree about the windshield not being a issue, especially if it is not perfectly even on both sides of the bike. Or if it starts bending in the wind, wobbling, causing a wobble in the bike. If shield leans to the right, the wind will push you left.
Of course the tires and bags should be looked at first.
I often have my ST1300 up to 120mph. (Stop right there, I don't need the haters and I'm not listening. ) Windscreen down, no top box, no wobble.

Sent from my SAMSUNG-SM-G935A using Tapatalk

Trying to run at a high speed with the shield up is just foolish IMHO. Try sticking your hand out of the window at a car at speed with your palm facing forward, and tell me the wind does not affect the drag your hand causes.
I'm in the same boat with everyone else in this thread...ditch the tires unless you can afford your medical co-pay for when your tires cause you to have an accident. Tires should be replaced every 5 years no matter what they look like.
Sounds to me that your issues (besides old hard tires and trying to push a shield against the wind) is that your preload adjuster is probably empty. Search the threads on how to service your preload adjuster, set the damping screw on 1.5 turns out from seated, and once you have your preload functional again, start at 5-6 clicks in from fully open to match the stock springs. I would also change the fork oil.

Picopower.
Now it's clear your tyres are as old as stated, please, please, change them.
Whether they are the cause of your weave is immaterial.
I cannot stress this enough you owe it to yourself, your friends, and your family not to die horribly from a tyre defect or an uncontrollable weave. Watch the video I suggested high speed weaves kill and maim riders.
There was a good reason the 13 was withdrawn from UK and other EU police use, they can be a handful if pushed too hard, bad tyres won't help.
Just my two'penneth​.
I'm waiting to be shot down in flames.
Upt'North.
All 13 riders out there please understand, I am not attacking the 13 at all, it is an exceptional motorcycle, but some can be a pig to keep in a straight line at speed, others are rock steady.

Hey Pico..... gotta agree with everyone here.....get new tires. PM sent as well......

ToddC

Upt' North said:

Picopower.
There was a good reason the 13 was withdrawn from UK and other EU police use, they can be a handful if pushed too hard, bad tyres won't help.
Just my two'penneth​.
I'm waiting to be shot down in flames.
Upt'North.
All 13 riders out there please understand, I am not attacking the 13 at all, it is an exceptional motorcycle, but some can be a pig to keep in a straight line at speed, others are rock steady.

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About the police use, I was told by a police bike mechanic that they cut part of the rear frame to fit in the radio. His words, " under the right circumstances the bike can just fold."
Maybe the reason they were pulled.

Dave.David said:

About the police use, I was told by a police bike mechanic that they cut part of the rear frame to fit in the radio. His words, " under the right circumstances the bike can just fold."
Maybe the reason they were pulled.

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:bsflag: This flag was not directed at our friend Dave.David, but to the "police bike mechanic" who dreamed up this stupid story.
I am sorry if Dave.David thought it was a reference to him.
My bad.

I have a 2012 ST. No problems at any speed. Loaded or unloaded. Bought new December 2014 and now has 16k miles. 65% of those miles are on the interstate at above 80 mph . If you are have a problem with stability something is not set up right. Start with changing your tires and service the bike. These are great bikes.

If you search the web enough, you may find the original test results for the UK police tests (or someone here may be nice enough to post it) as I can't find it at the moment.
One of the tests showed several different runs, shield up, shield down, bags full, bags empty, preload minimum, preload maximum etc.
It was interesting because the best handling, most stable set up was with the preload adjuster near the factory setting, or lower!

The Bike mag tests from 2007 were actually inconclusive with weave appearing (or not) with different suspension, pannier loads, and windshield heights. A second test by the same magazine that totaled 400 miles concluded that with a light solo rider increasingly adding preloaded reduced weave. This mirrors my experience.

Changing the worn caged ball bearings in the head stock at 96,000 miles to tapered rollers pretty much completely removed any tendency to weave when lightly loaded even when running to speeds just over 140 mph.