Pan Weave

I would like to attack my pan weave which is very consistent in the 100-110mph range depending on road conditions. I do a lot of Autobahn so it is really bothering me..

I will change the steering head bearing back to ball bearing (Conical was VERY counter-productive), remove the auto-levelling Wilburs nivomat, set-up is not good for me ( "comfort" option selected, the rear ride height is WAY high). Then I can start to play with dropping the triples, see if it helps...

Does anybody recommend to replace the swing-arm bearings ? or just re-setting the torque ? Bike is at 62k miles.
I have been playing with the idea to change the steering angle by replacing the triples with machined versions with a different angle on the fork-holes.. probably very complicated and $$$ to achieve, but am desperate to stabilise the bike...

Any suggestions welcome
 
Superdirk said:
I would like to attack my pan weave which is very consistent in the 100-110mph range depending on road conditions. I do a lot of Autobahn so it is really bothering me..

I will change the steering head bearing back to ball bearing (Conical was VERY counter-productive), remove the auto-levelling Wilburs nivomat, set-up is not good for me ( "comfort" option selected, the rear ride height is WAY high). Then I can start to play with dropping the triples, see if it helps...

Does anybody recommend to replace the swing-arm bearings ? or just re-setting the torque ? Bike is at 62k miles.
I have been playing with the idea to change the steering angle by replacing the triples with machined versions with a different angle on the fork-holes.. probably very complicated and $$$ to achieve, but am desperate to stabilise the bike...

Any suggestions welcome
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I just wanted to get rid of my ST because of the weave starting at 80mph!

Does it happens the same way with a tank full or close to empty?
If you feel a notable difference, back preload is the way to start.
Did you have the opportunity to check it with different front tires?
I had the problem with Dunlop on the front never with Michelin or Shinko.
At the end I replaced the oil in the fork and shock by a 7.5W, checked and retorqued swing arm and steering head bearing to spec and never happened again.
Also check if you have the proper quantity of oil in the fork.
My suspension is a little bit hard now, but the bike is on rails at high speeds.
I am sure that you will be successful, good luck!
 
I would like to ask a question to the Aeronautics people here.

When I look at the silhouette of the 1300 I see where lift can certainly occur. After installing the wind deflectors it seems even more likely. Does this seem to be in like with airplanes? Is it not why MotoGP put on wings?
 
TourNut said:
I read one article that said Honda's factory of the ST would test ride each to see how much shims to put in the swingarm bearing area to prevent movement that causes " the weave ". Sounds like a "hit or miss" deal there & I wonder about future wear in the swingarm set up maybe causing it then ?
Click to expand...

Where might i aquire these shims?

Would anyone know?
 
Savago said:
Experienced the weave once: 130mph + trunk + windshield up + bike fully loaded (panniers, trunk, medium bag in the rear seat).

What I thought was scary is that there was no warning: the bike was stable and suddenly started to weave side-to-side. Really scary!

Keep it under 120mph and you should be fine.
Click to expand...

Sounds like your's was setup correctly.

I think i might agree that something mechanical could fail and need replaced
 
Probably beating a dead horse here, but as a new Pan European owner (02 model), I felt this weave last Sunday when riding with my wife as a pillion and with the windscreen up; I was doing between 100 and 120 kmph on the highway, a bit windy but nothing crazy, I noticed that past 110 kmph it randomly showed up, if I slowed down to 100 kmph or less the weave stopped. It felt like if the front wheel was crooked, like it felt on my XR650L when the front wheel was indeed crooked, lol.
 
ST-Charro said:
Probably beating a dead horse here, but as a new Pan European owner (02 model), I felt this weave last Sunday when riding with my wife as a pillion and with the windscreen up; I was doing between 100 and 120 kmph on the highway, a bit windy but nothing crazy, I noticed that past 110 kmph it randomly showed up, if I slowed down to 100 kmph or less the weave stopped. It felt like if the front wheel was crooked, like it felt on my XR650L when the front wheel was indeed crooked, lol.
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Charro.
For all the reasons already stated it does happen to some bikes.
After checking all the normal and already covered items there's not a lot you can do.
The main items to check IMO FWIW in order of importance would be tyres and wheel fitment, bearings including headstock and suspension set up.
Tyres can make a huge difference but only if everything else is sorted too.
Someone will know but I believe Honda did something to the early bikes under recall. Although it's probably already covered here.
Good luck.
Upt.
 
About half-way through the article found in the below link.

A Perfectly Stable ST1300 Overtaking A Semi | ST1300 Related

“My '04 GS Adventure was all but unridable with the Jesse 50 liter top box mounted. Would go into a weave at anything over 80. Sans the box but with the panniers, it was OK up to 120 or so. With a small bag mounted on the pillion, the weave would come back at around 110.”
www.st-owners.com www.st-owners.com
 
Maybe thats why Honda put speed limiters on police models. Maybe thats why Honda discontinued the ST1300.

from Wiki

Pan weave​

[edit]
Evidence indicates the ST1300 can exhibit a weave instability mode at high speed – known in the case of the ST1300 as Pan Weave.

In April 2007, subsequent to the death of a police motorcyclist riding a single seat ST1300, the emergency service version of the ST1300, a British coroner announced he would warn all Chief Constables in England and Wales of the "serious threat" to riders' lives posed by the ST1300 and the "catastrophic result" of the high speed weave.[18] Later safety checks resulted in one examiner sustaining several broken bones in a similar incident. UK police forces subsequently withdrew the ST1300 from police service;[19] London Ambulance Service continue to operate the ST1300.[20][21]

RiDE Magazine reported in October 2007 that a team replicated weave instability mode with a civilian Honda ST1300 – reproducing the instability at a speed of 110 miles per hour (180 km/h) under certain loading conditions. The rider noticed a rear wheel maximum yaw of 11 degrees per second, described as "a consistent and alarming sideways movement." The editors named the behavior "Pan weave". The intent of the testing was not to determine the cause of the weave, but to confirm its existence. Also, the article reported that 43% of surveyed ST1300 owners had experienced the weave.[22]

Honda's response​

[edit]
American Honda published an advisory in August 2007 on the proper selection, installation, and use of equipment on the ST1300PA police motorcycle.[23] They made a strong recommendation to have "qualified personnel evaluate a motorcycle fitted with all intended equipment under the anticipated speeds and conditions before the vehicle is placed into service." The advisory also contained guidelines for the selection and installation of attachments, including:[24]

  • Place equipment as low and close to the center of the motorcycle as possible;
  • avoid exceeding the maximum load limit for the vehicle;
  • comply with weight limits for each saddlebag and fairing pocket;
  • ensure attachments and equipment are balanced on both sides of the vehicle.
 
If Honda engineers could not solve the problem, what make you think thats somethings wrong or you can fix it? Do a normal inspection, if you find a problem fix it if not don't throw parts at it and drive somewhat normal.
 
I've found my bike is happier at motorway speeds without the top box than with. The airflow off me will be turbulent and probably sets up a vortex between me and the box. I'm not sure this is the entire story though, but I did find that my big Lomo bag sitting on the pillion seat did seem to help a little. That said, bestie said she was buffeted quite a bit when pillioning with me.

My pet hypothesis is because the swingarm is not symmetric: it has the spring and damper mounted on one side, and has the prop shaft inside it. Small amounts of torsion will exist between the rear axle, the swingarm pivot and the shock's lower mount, and there will be some small rotation of the axle relative to the tyre contact patch, and that rotation is also elastic so my question is whether surface undulations and/or air turbulence at a given speed could approach some resonant frequency of the swingarm. It doesn't explain why the 1100 didn't experience weave though, except that it has a steel swingarm of a different shape too, so its resonant frequency would be different.
 
Arellcat said:
My pet hypothesis is because the swingarm is not symmetric: it has the spring and damper mounted on one side, and has the prop shaft inside it. Small amounts of torsion will exist between the rear axle, the swingarm pivot and the shock's lower mount, and there will be some small rotation of the axle relative to the tyre contact patch, and that rotation is also elastic so my question is whether surface undulations and/or air turbulence at a given speed could approach some resonant frequency of the swingarm. It doesn't explain why the 1100 didn't experience weave though, except that it has a steel swingarm of a different shape too, so its resonant frequency would be different.
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Nods knowingly with chin in hand......
 
Arellcat said:
I've found my bike is happier at motorway speeds without the top box than with. The airflow off me will be turbulent and probably sets up a vortex between me and the box. I'm not sure this is the entire story though, but I did find that my big Lomo bag sitting on the pillion seat did seem to help a little. That said, bestie said she was buffeted quite a bit when pillioning with me.

My pet hypothesis is because the swingarm is not symmetric: it has the spring and damper mounted on one side, and has the prop shaft inside it. Small amounts of torsion will exist between the rear axle, the swingarm pivot and the shock's lower mount, and there will be some small rotation of the axle relative to the tyre contact patch, and that rotation is also elastic so my question is whether surface undulations and/or air turbulence at a given speed could approach some resonant frequency of the swingarm. It doesn't explain why the 1100 didn't experience weave though, except that it has a steel swingarm of a different shape too, so its resonant frequency would be different.
Click to expand...
The 1100's did. But seemed tyre dependent. I had a new out of the box ST11 on Dunlops that tried to kill me.
All bikes are capable of a wobble, all bikes weave, just some are better at it than others. Where the ST13 got it drastically wrong is when they did it they did kill people.
Honda XR400's would weave insanely on knobblies.
Earlier Japanese bikes were renowned for it too, but today you would have to upset and neglect the bikes an awful lot to experience the same.
Upt.
 
If the weave wont show bellow 110 kmph, I can live with that, that would also be a punishment/warning for me if I ever get throttle happy :ang1:
 
This weave is what has kept me off a ST1300, although I probably wouldn't go fast enough on it anymore for it to be an issue. The bike sure is easy on the eyes, though.

My unqualified thoughts....be nice to me if they're way off the mark.)

When I had the stock shock on my Blackbird, I noticed the back end would wallow in highish speed corners when the rear would pack down. Then, one day, the rear moved out and felt like I'd hit a patch of gravel on the road when going around a corner. Later, I was going around a corner at maybe 50-55mph and the bike developed a severe tank slapper that I couldn't control and off I went to the hospital. I totaled the bike. All things pointed to a suspension problem so I rebuilt the bike and put a properly sprung Penske shock with increased ride height on it. I also replaced the races and steering head bearings, wheel bearings, etc. I didn't touch the swingarm bearings or shock linkage. No problems since.

I think the Pan Weave is suspension-related in that there is a geometry and weight distribution change that the bike is sensitive to at speed. I also think that it's an issue of aerodynamics at the front that are contributing to it. That whole fairing and windscreen looks like it would create a lot of lift at speed rather than pushing the front of the bike downwards. If lift is being created, a topbox creating its own weight distribution and aerodynamic issues would surely make things worse. Has anyone run the bike up to speed without the windscreen? Or without the entire front fairing assembly? Does the steering get lighter or heavier at weave speeds? Has anyone tried MotoGP type wings on the fairing to create downforce?
 
I've never experienced any weave on my 1300 in 9 years of ownership, with or without a topbox, and at speeds up to 100 mph (about 160 kph). Some bikes apparently do it more than others.
 
RobbieAG said:
I've never experienced any weave on my 1300 in 9 years of ownership, with or without a topbox, and at speeds up to 100 mph (about 160 kph). Some bikes apparently do it more than others.
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I guess one of the only ways to get to the bottom of it is to get two absolutely identical bikes - one with weave and one without - and put the same rider on each one to see what happens. Without telling the rider which is which, of course.

If an owner of an ST1300 does something that corrects the weave for him/her - and I'm assuming this has happened - why don't all the other owners do the same thing? At some point, there should be a consensus of things that work and things that don't.
 
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