Pushed around by trucks

At high speeds and passing 40' containers I get a weaving that is akin to riding a snake through the grass. I have installed new tapered steering bearings and suspect I got them a bit tight although that condition on a BMW R100PD gave me more of a front wheel slide sensation side to side. Opinions please. I'm also running with a 4" higher CEEBailey and a Givi Blade trunk. The rear shock is new (OEM) and load adjustment at 2 from bottom. My weight is 190.

Also, to adjust the torque again do I need to remove the wheel and go through all the alignment procedure as when I changed the bearings?

At near 70K miles the wheel bearings checked good last week, new PR3 tires front and rear and set at 36/42 front /rear. Are the swing arm bearings usually good at this distance or should I replace them? Can anyone provide a link to a special tool source for these two jobs? Without the usual Honda parts cost? I found on flea bay Horsepower-House tools listed but have not verified with anyone. I borrowed the special tools for the bearing change but would like to buy the tools for the next go round.

Special thanks,

Rob

Don't hold on too tightly and it seems to be less of an issue. If you "Death Grip" the handlebars it will seem worse. I just ride it out.

I look forward to the other suggestions too.

Mike

Many moons ago, we installed belly pans to help with this. It closes the opening of the bottom cowling. Some say it makes all the difference in the world, some say it doesn't. I have them on all three of my ST1100s and what I get is one 'hit' and then the bikes seem to stabilize. YEMV. ;-)

Uncle Phil said:

Many moons ago, we installed belly pans to help with this. It closes the opening of the bottom cowling. Some say it makes all the difference in the world, some say it doesn't. I have them on all three of my ST1100s and what I get is one 'hit' and then the bikes seem to stabilize. YEMV. ;-)

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+1 along with well maintained suspension on both ends...

I also run mine with a front fork brace and a custom air deflector under the front cowl.

My ST1100 wiggles when I ride through the 'bow waves' around tractor trailers. This is normal...your car does it too.
Compared with my unfaired GL1000's and CB750...ST's are no problem.

I appreciate the responses but I don't recall this ever being a problem before. At first I thought it might be the trunk and large screen resistance upsetting the air flow. The problem with testing is I live just over an hour from I-75 and between the weather and a broken tail bone I'm finding it hard to run back and forth at my leisure. If anyone has the experience to compare, I got the chance to ride a 2015 FJR1300ES the same day I experienced the weave and it was rock steady in the same conditions. But the shield was stock and there was no trunk.
As for the tools I mentioned here are a couple of links if anyone is interested or can give me some input
http://stores.ebay.com/Horsepower-House/Slotted-Lock-Nut-Tools-/_i.html?_fsub=18393535011&_sid=90037321&_trksid=p4634.c0.m322

The first tool on top row. There is another down the page that might work for the swingarm.

Rob

Outlaws said:

+1 along with well maintained suspension on both ends...

I also run mine with a front fork brace and a custom air deflector under the front cowl.

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We used call that 'custom air deflector under the front cowl' a STEFI plate ... I've got those also.

I have experienced this in the past with a +4 clearview, give trunk and bias ply tires. Change any one and it went away. I now have a slightly shorter shield and it is fine with bias or radial trunk or no trunk.


Ashley

Thanks for that Ashley.

Can anyone provide a drawing or picture of the air deflector and belly pan?

Last year I refilled the rear shock preload adjuster and, in a moment of 'if it ain't broke, lets make it better' loosened the dampening screw on the shock itself. Voila - the turbulent air behind semi's gave me the weaves. Since that was my only change in the winter layup, and after suggestions here to 'unfix what I fixed' I tightened up the dampening and preload a bit (I had wanted a softer ride - and didn't notice much difference after I had eased the dampening and preload) and the bike went back to her old stable self.

So, you might check the preload adjuster and maybe tighten up the dampening screw 1/8 of a turn or so. Then maybe another 8th if that doesn't change things.

Its also not a good idea to ride behind these big trucks - they can throw road debris quite a way back.

I went from a +4" Cee Bailey screen to a Laminar Lip Combo and have noticed a decrease in the amount of turbulence I feel around trucks and in crosswinds. I haven't done controlled back to back tests so it is possible that it is just confirmation bias but I thought the big screen was catching more air and added to the weaving.

The extra tall windshield may be some of the problem along with the top box... that being said, you may want to back of the tension of the steering head bearing some. With the front end up in the air you want to be able to move the front end from side to side with minimum effort but it should not flop from side to side on its own. Steering head bearing being too tight can give you the weaves. You should not have to remove the front wheel, just remove the handlebars, and loosen the lock nut, straighten the locking tang on the lock washer, back off the steering stem nut a little and test the movement again. It helps if you have something overhead or a helper to support the handlebars while you are preforming the adjustment to keep the cables from influencing the movement. Like I said, minimum effort with no flop.

Wow! That's embarrassingly dirty and who scraps the sides of these things...

Belly pan from a scrap piece of aluminum cut to fit inside the opening secured at the front by factory screws that the attach the two sides and a couple of machine screws with lock washers and nuts along the side. Have not had time to get into the wind tunnel to measure the lift and low pressure vacuum created by the little lip bent down in the back but am confident it is substantial...

Under cowl piece from an old tin back of some home appliance. Made up a cardboard template and kept trimming till cleared the forks tubes and brace. Added a couple blind rivet nuts into the side panels to mount the back with the front obviously using factory screws. This view is from below, it directs air at speed under the lower tree directly into the radiator.

That's it.

Again, thanks to all. Preferring the shotgun approach, it seems I've got a lot to do.

Plus 1 on the Stefi plate and belly pan. Seems to help on mine with a +3 Clearview and 52L Givi trunk. I also made a quick detach method of securing the saddlebags to the rear fender. Who needs them flopping around too?

SMSW said:

So, you might check the preload adjuster and maybe tighten up the dampening screw 1/8 of a turn or so.

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Sure wish my 1100 had a pre load adjuster

Ashley said:

Sure wish my 1100 had a pre load adjuster

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Oh well, maybe I should have checked the bike before i posted my reply. Sorry.

Ashley said:

Sure wish my 1100 had a pre load adjuster

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Well, there is one... for the rear spring though... ;-)

I fully agree with Vinny that (too) tall windscreens and the (unneeded when riding solo) topcase are the major contributors in that "bow wave" issue, as well as getting shaken up in the drag when following a semi too close...
Get an appropriate sized windscreen, loose the topcase and trust on the "auto-lean" of the ST1100... no kidden, ease up on the handlebar and let the bike choose its leaning angle in side-winds; it works, the rig actually knows what its doing... ;-)

I've been on this forum for almost three years. First time I've heard of the Stefi Plate and belly fairing fillet. Thanks Phil! any other great tidbits of knowledge you can pass along? Now I've got more mods to do!

Well, there is the 'flip clip' handle bar riser mod, the police switch mod, the adjustable windshield mod (from MADSTAD Engineering) - just to mention a few!