High speed handling issue

Joined
Sep 11, 2011
Messages
32
Location
Scottsdale AZ
Bike
2006 Honda ST1300
I just replaced both of my tires using Michelin Pilot 4 GT's. Under 70 MPH the handling is great, but over that speed the handling feels squirrelly. I have a Clearview aftermarket windshield and I know that it is contributing to my issue since when I adjust it lower the squirrelly feeling gets less severe, but does not go away. I also notice that when I am around other vehicles it seems as though the issue gets worse due to how the air from their vehicle is being moved around and hits the bike. I reseated the axle to ensure that everything was aligned and not twisted and then re-torqued all bolts. I even attempted to adjust the rear shock settings, but nothing made a difference. I already replaced the steering head bearings with tapered ones and they seem to be adjusted correctly (turns freely from side to side and no play when checked while front end is lifted).
I guess that the tread design has a lot to do with this issue since I didn't experience it with the previous Michelin tires and it also has to do with the aerodynamics of the windshield and that a fork brace may help with this issue? Any thoughts? If so, Superbrace or Motorcycle Larry fork brace?
Any suggestions or thoughts?

Thanks
 
Joined
Jan 8, 2011
Messages
7,062
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Arizona
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2007 Honda ST1300A
A few questions for you...
What are you carrying in your saddlebags or trunk? How much weight?
Have you serviced your pre-load adjuster, and replaced the fluid? (search forum)
I am not big on fork braces, as they can cause more steering and handling problems than not. I have had several bikes come through the garage with fork braces that caused the forks to be crooked and misaligned due to the way they were machined, and caused bind on the forks and axle.
Here's what I would try first.
1. Service your preload adjuster
2. Set it at two turns in only (4 clicks)
3. Set the damping screw on the bottom of the shock to 1.5 turns out from fully closed (turn clockwise till it gently stops, then 1.5 turns counter clockwise)
4. Remove everything from your bags, run your shield in the low position, and make sure your tire pressure gauge is correct, and you have 42 psi in both tires.

Report back on how it handles after this is completed.

What year bike?
How many miles?
Are you having any brake dragging issues on either wheel?
When was the last time you checked your driven bearings in the rear wheel?

PM a contact number to me if you would like to discuss any of these instructions further.
Igofar
 
Joined
Jul 15, 2015
Messages
46
Location
Rock Spring, GA
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ST1300
Very curious issue you have. I do know that lowering the wind screen helps with handling at freeway speeds and above though. I wear a half helmet more than not and run my screen up to keep wind from hitting me in the face hard but when I wear a full face helmet I run the screen down and it is so much better on the interstate at 70mph and up. It has never been really bad like you describe though with the screen up so I am sure you have something else going on. As stated above check first for improper mounting direction on your tires. Then check other things out. If the tires are mounted correctly they could still be defective and it would be nice if you could mount someone else's tires and try to see if you can verify tire problem or not.
 
Joined
Apr 10, 2012
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Donegal, Ireland.
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Vstrom 650
I like to ride with the top box, but it can make the back end wiggle about depending on which way the wind blows.
I can imagine that the new adventure style metal luggage eg the giant Givi trekker outback 58 litre would make this problem worse, at least the plastic top boxes have a profile that is a bit more aerodynamic.
 
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Donegal, Ireland.
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Of course, that is another factor - but it is me that isn't aerodynamic. I create a massive eddy - I am beautifully proportioned (viewed in an appropriately curved mirror) and at 6'4" there is quite some turbulence there. Those large flying insects that you don't see until the last second ? - The ones that don't hit me buzz past. A fraction of a second later, they have got caught in the eddy and come hurtling past me from behind and smash themselves onto the inside of my windscreen.
You paint an interesting picture John :) I think I'm going to try riding without a top box in future unless it's really needed, I have discovered my new HJC size L helmet fits ok in the pannier.
I can feel that pressure on my back on the ST alright,and she can be very twitchy in crosswinds, particularly in one mountain pass near me, there is some kind of vortex there on windy days and it can affect the bike very suddenly, it's ok now I am aware of it but the first time it happened it was interesting,
I am 6'1" I have an mra maxia vario screen.
 
Joined
Jan 8, 2011
Messages
7,062
Location
Arizona
Bike
2007 Honda ST1300A
Of course, that is another factor - but it is me that isn't aerodynamic. I create a massive eddy - I am beautifully proportioned (viewed in an appropriately curved mirror) and at 6'4" there is quite some turbulence there. Those large flying insects that you don't see until the last second ? - The ones that don't hit me buzz past. A fraction of a second later, they have got caught in the eddy and come hurtling past me from behind and smash themselves onto the inside of my windscreen.
I think you will find that the insects hit the black plastic dash cowl and then ricochet up onto the inside of your shield between the gap of the shield and the cowl, and don't really come from behind you :rofl1:
 

MajorTom

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I have Michelin PR4 GTs on my '04 ST1300 and installed the front about 8k km ago, just before heading out to eastern Canada on a 7k km trip. I have a standard screen and a top box mounted. In no way could I describe the bike's handling as "squirelly" under any of the conditions I've ridden in, including riding in heavy rain on new pavement, two up and near (or maybe over) the max GVWR. I suspect something else is in play than the tire brand and fitment.
 

dduelin

Tune my heart to sing Thy grace
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Riding weight. The ST1300 rear shock is quite undersprung for riders of 160 lbs or more and all two up riding and needs at least 7 clicks of preload to the Standard setting and more than than for high speed solo riding and for all heavier riders. Less than that and the rear of the bike is prone to oscillating up and down and feeding forces into the frame that can develop into the well documented ST1300 Weave. This subject is beat absolutely to death in here: https://www.st-owners.com/forums/forumdisplay.php?479-ST1300-Suspension

The ST1300 is not particularly stable at very high speeds and at somewhat lower supra legal speeds in the dirty air of traffic. Generally speaking probably nothing is wrong with the particular bike it is just the characteristics of this bike. Proper tire pressures and suspension set up help to settle it down. The twitchiness or "happy feet" at speed in traffic is one of the prices we pay for the light, neutral, and quick steering in the twisties. I'd venture PR4s are among the slower handling tire fitments which is odd considering the OP's complaint after the tire change.
 
Joined
Sep 22, 2015
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1,282
Location
Wasaga Beach, Ont. Canada
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'04 ST1300 Blue STar
I noticed some interesting handling characteristics of my '04 ST1300 Blue STar this summer,, with respect to high speed handling. My bike is stock suspension,, mirror deflectors,, Clearview GT shield,, and no top case when solo. At high speed on the interstates,, it is a bit skiddish,, kind of twitchy,,, and I think that is a result of the full fairing aerodynamics and the ability of the low rake and trail of the front end design to handle turbulence. It can be a bit irritating,, but not dangerous. Then I noticed that when my wife rides with me,,, Blue STar is definitely more stable (less twitchy) at all speeds. And that is when there is an extra person,, and the givi top case is in place. So what is different between those two situations. One, there is more inertia, which resists against turbulent influences. Also,, the aero is changed over the bike,, due to the passenger and top box being in place. Also,, the extra weight on board,, lowers the back end and increases the rake/trail geometry slightly in the desired direction, for increased stability. Now a large blast of cross wind is going to have a different and more severe effect than a bit of, mostly forward, turbulence. So what I take from that comparison is that, when riding solo, I don't want my top case on. Don't want excess front end sag. Don't want the shield up any farther than needed. Don't want the rear suspension up any higher than it needs to be. All the other points made in the prior posts are valid too. I just wanted to add these for consideration as well,,, cheers,, Cat'
 
Joined
Sep 4, 2013
Messages
8,109
Location
Cleveland
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2010 ST1300
Of course, that is another factor - but it is me that isn't aerodynamic. I create a massive eddy - I am beautifully proportioned (viewed in an appropriately curved mirror) and at 6'4" there is quite some turbulence there. Those large flying insects that you don't see until the last second ? - The ones that don't hit me buzz past. A fraction of a second later, they have got caught in the eddy and come hurtling past me from behind and smash themselves onto the inside of my windscreen.
John, Maybe you need a ping pong paddle to whack them as they pass you?

I just replaced both of my tires using Michelin Pilot 4 GT's. Under 70 MPH the handling is great, but over that speed the handling feels squirrelly. I have a Clearview aftermarket windshield and I know that it is contributing to my issue since when I adjust it lower the squirrelly feeling gets less severe, but does not go away. I also notice that when I am around other vehicles it seems as though the issue gets worse due to how the air from their vehicle is being moved around and hits the bike. I reseated the axle to ensure that everything was aligned and not twisted and then re-torqued all bolts. I even attempted to adjust the rear shock settings, but nothing made a difference. I already replaced the steering head bearings with tapered ones and they seem to be adjusted correctly (turns freely from side to side and no play when checked while front end is lifted).
I guess that the tread design has a lot to do with this issue since I didn't experience it with the previous Michelin tires and it also has to do with the aerodynamics of the windshield and that a fork brace may help with this issue? Any thoughts? If so, Superbrace or Motorcycle Larry fork brace?
Any suggestions or thoughts?

Thanks
Barry, I echo what Larry said (Post #2). My bike was more or less fine, then one winter I juiced up my preload adjuster and played with the damping screw on the shock. Bad move. Next spring the bike was terrible in turbulence behind semi's. Tweaked the damping screw and that brought the bike back to normal. With my Calsci windshield I do have a little 'uncertainty' or wobble at just the right point behind a semi, but nothing serious. I weigh 150 and always ride alone.

Somebody recently had trouble getting an MCL fork brace to fit on his bike, and I think it was mentioned that the fender mount stiffens the forks. So, while the brace might do you some good, I'm not sure it will make that significant a difference on the slab (big assumption here - you are not doing 70+ on roads like Tail of the Dragon).
 
OP
OP
Joined
Sep 11, 2011
Messages
32
Location
Scottsdale AZ
Bike
2006 Honda ST1300
Please see my replies below;
I don't have a top box, I weigh approx. 175 lbs and typically ride solo.

A few questions for you...
What are you carrying in your saddlebags or trunk? Basic tools in left bag How much weight? Approximately 5 lbs
Have you serviced your pre-load adjuster, and replaced the fluid? (search forum) No, not yet but I will put on on my to-do list
I am not big on fork braces, as they can cause more steering and handling problems than not. I have had several bikes come through the garage with fork braces that caused the forks to be crooked and misaligned due to the way they were machined, and caused bind on the forks and axle.
Here's what I would try first.
1. Service your preload adjuster
2. Set it at two turns in only (4 clicks)
3. Set the damping screw on the bottom of the shock to 1.5 turns out from fully closed (turn clockwise till it gently stops, then 1.5 turns counter clockwise)
4. Remove everything from your bags, run your shield in the low position, and make sure your tire pressure gauge is correct, and you have 42 psi in both tires.

Report back on how it handles after this is completed.

What year bike? 2006
How many miles? Approx 21k
Are you having any brake dragging issues on either wheel? No
When was the last time you checked your driven bearings in the rear wheel? Recently when the tire was replaced

PM a contact number to me if you would like to discuss any of these instructions further.
Igofar
I will attempt some of the simpler suggestions that you and others have made and will let you know the results. If those don't work I will then attempt the others.

Thanks to you and everyone else that replied!
 

SteveST1300

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Don't just set your suspension you need to check for proper sag blindly adjusting multiple things will not let you find your issue try one setting change at a time but you do need more preload on the stock shock/spring. Look for the article ddulin posted about setting sag its very good.
 

mlheck

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How many miles are on the rear shock? Anything over 40-50k and you are looking at a worn rear shock. I've been where you are at and replaced all kinds of bearings and bushings before replacing the rear shock. Replacing the rear shock solved the problem.

At higher speeds a worn rear shock will not control the small movements of the suspension and make the bike feel very loose.
 
Joined
Jan 14, 2018
Messages
138
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New jersey
Bike
St1300PA
Got my bike with New pr2s put 11,000 miles on them second set I put pr3s on and started have troubles after going over everything I couldn't find anything with 4,000 miles on the pr3s I took them off, With a cross country ride coming up I had a set of pr4s put on and had a wobble at 65-70 put pirellis on angel GT and I couldn't ask for anything more as the bike runs great with them no wobble at all I'm on my third set
 
Joined
Feb 2, 2014
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1,857
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houston, tx
I'd follow Larry's advice - be sure to do one adjustment at a time (for example, shock adjustment), then ride, to see if that fixed it.

I've had PR4 GTs on the 2003 and was never sold on them. I toggle between T30 GTs and Angel GTs, and if you hold me to a decision, I'll pick the Angel GTs.

Opinion piece: I've been riding 45+ years and have never had a need or want to exceed 70mph. I avoid multi-lane freeways at all costs (ever read Zen and the Art of Motorcycle Maintenance??) and prefer the lonely, lazy backroads, which precludes high speeds. The ST, with large Givi, standard windscreen, better half pillion, is stable at 60-65; with me alone, great at 65-70mph, so can't effectively comment on stability over 70.
 
Joined
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If all you did is change the tyres, then I think it's the tyres.
The advice re checking pre loader etc is all good, but if it rode OK the day before then I can't see what else changed.
Tyres make a huge difference to the 11, some are planted and some are down right, yes, squirrelly. Good word innit. I know the 13's have their own issues with handling, engine mounts etc, but if all you did is change tyres?
I recently went from 023's to T30 Bridgestones' even though they're from the same manufacturer, they are very different in feel.
Good luck.
Upt'North.
Alternatively......Pie diet might be fun.
 
Joined
Sep 4, 2013
Messages
8,109
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Cleveland
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2010 ST1300
I'd follow Larry's advice.

can't effectively comment on stability over 70.
+1 on following Larry's suggestions. My bike is stable at 75, and all the way up to the highest speed I've taken it (under three digits). Only problems I have had are in very turbulent air - behind semi trailers and other rectangular trucks. If you have read about the vortex that can flip a light plane flying behind a landing big jet, you will understand what is going on here - the buffeting behind some trucks will give almost any bike a shake.
 

jfheath

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If all you did is change the tyres, then I think it's the tyres.
The advice re checking pre loader etc is all good, but if it rode OK the day before then I can't see what else changed.
Tyres make a huge difference to the 11, some are planted and some are down right, yes, squirrelly. Good word innit. I know the 13's have their own issues with handling, engine mounts etc, but if all you did is change tyres?
I recently went from 023's to T30 Bridgestones' even though they're from the same manufacturer, they are very different in feel.
:plus1:

Another significant factor is the stiffness of the tyre wall. Bridgestone seem to thoroughly test their tyres with the St1100 and ST1300, and they make their recommendations based on how the bike handles - and make 'F' rated tyres for their BT020s and GT rated tyres for the more recent ones (021, 023, T30) Although you can get other makes of tyres that fit, they are not necessarily tested to the same degree. (USA had the 023s much earlier than we had in the UK - when I asked the question of Bridgestone, they told me that they were still testing them for the 'Pans' in Scotland. )

I don't require an answer to the next question, but consider your own and your pillion's weight. When another rider makes a recommendation, it might be that their riding weight is nothing like your own - be it heavier or lighter. I've always used Bridgestones and I ride with a pillion and often camping gear and we are up to the maximum weight limit of the ST1300. I typically get 5K miles from a rear, and the bike always feels secure, although I stick to the speed limits, it felt perfectly fine on the derestricted german autobahns.

My 023GTs were superb - for the first 1500 miles. After that the outer part of the tread was wearing down much faster on the rear than the centre, and it was beginning to get a grainy texture on the surface. The rear end started to feel very loose - I reckon the textured was moving around more than the normal tyre surface. The T30 GT Evos - I love although the tyre wear is still to be established.
 
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