Weaving?

[jimbo66]

Hi All,

Really sorry to post this in general, I am new, and have had a quick look, I am sure that this subject has already been mentioned, and I have already been advised that no doubt I would get bombarded with various options.

Also apologise to the Admin's if I have posted this in the incorrect place on this forum :-(

So, here goes.

Just picked up my first PAN ST1300 (2005) on 12th November, I know there are more plastics on this type of bike than Michael Jackson face (RIP), after picking the bike up, and around 70Mph, the bike felt uneasy, weaving, unstable. I have seen that I could try removing the topbox, lowering the screen, fiddling with the rear suspension could help (I haven't tried any of these yet). I have done some homework, and I understood that the weaving on early bikes (pre 2004) Honda did address this and fixed it.
It maybe only a confidence thing, but really want to understand why? and how to rectify this.

I know Triumph has a floating topbox plate so any wind turbulence that hits this the topbox slightly, as in a way the topbox is not directly attached to the bike (topbox moves without causing any instability to the bike handling).
As I will be touring a lot next year (with 2 up), will this settle carrying a pillion and topbox?
can anyone recommend anything to improve the stability?

I understand that some people have never had or experienced weaving, so really just want to understand why some people have and some people haven't and what are those differences.

Any help will be greatly appreciated.

Thanks

James

 

[ibike2havefun]

Hi-

I've never experienced it myself so take that into consideration as you read. I've also never had my ST beyond 90 mph, but at all speeds up to 90 it has been rock-steady except in windy or turbulent air such as exists behind large trucks traveling at highway speeds.

The reports and documented cases of the notorious "Pan weave" all involved speeds much greater than 70 mph (well into the triple digits) and specific loading. It is also described as a violent, abrupt action, not "just" a wobble.

Was it a windy day when you experienced this? The bodywork does make these things into sails, despite their heft.

When I replaced the tires that were on my bike (a 2004 model) when I bought it, I changed brands of tire as well as replacing worn with new. As you'd expect with new tires, the handling improved noticeably. I have not noticed so dramatic a change after my most recent tire change, which also changed brands as well as replacing worn rubber with fresh.

I've found that my GIVI changes things only subtly, though I am careful to limit the weight I put in it. When I am on a loaded ride, I generally try to load heavier items into the saddlebags and leave things like rain gear, the travel cover, and other relatively lightweight items for the GIVI. I've yet to ride two-up so can't provide experience there.

You might check that the tires are properly inflated and not worn; check / adjust the rear suspension pre-load setting (and also check whether it has been serviced-- the adjuster mechanism is known to lose fluid over time); ensure that the wheels actually are correctly installed and the bolts all tightened to the proper specs and in the proper sequence (this may entail loosening then re-tightening them EXACTLY as described in the Honda service manual so that you know from personal experience that it's been done to spec).

All of these are the easy things. Checking steering head bearings is something I've not done but have read about. If they have worn or somehow worked loose I can imagine it would not be a Good Thing but I can't speak to it through personal experience. The same for wheel bearings, of course.

How many miles on your new-to-you ride? Is it the OEM windscreen or an after-market model? Do you have the service history? Have you had the bike checked over and baselined?

Hope this gives you some ideas of things to look into.

 

[dduelin]

Don't worry - you will get plenty of suggestions but if you are scared of the bike at 70 mph you might ought to sell it and move on to something else.

 

[jettawreck]

I would first be looking at tire condition. Subtle odd wear patterns can make for some unsettling handling characteristics.
Never had any "weave" issues regardless of top box or passenger loads, in fact passenger makes for little noticeable change at speed once moving.
Lots of possibilities, but what you are/have experienced is not, as mentioned, anything like the rare "Pan weave".

 

[SteveST1300]

The bike does get twitchy around big trucks but at 70 should be rock solid I have had my 03 well over 100 MPH and had no issues check your sag and adjust the suspension properly and then try it. Make sure tires are inflated properly.

 

[Upt' North]

Jimbo,
I ride an 1100 so can't comment specifically on the 1300 but I have ridden one or two.
The only thing IMO you can do to affect thd handling is tyres and suspension.
I rode an 1100 on Dunlop's in the mid 90's and it was though it was hinged in the middle at even legal speeds. A change to Bridgestone's changed the bike completely and it didn't start to feel light until 100 plus and it didn't start to weave until 120 plus. Speeds that won't bother most of us day to day.
Check your suspension, I suspect it will be just fine and then find someone who has got a 1300 that doesn't weave and fit the same tyres, I would go for Honda recommended fitments. Bridgestone Evo's are getting good reviews I believe.
Also IMO I believe some weave and some don't, my own 1100 is rock steady regardless of tyres and loading and others are pigs.
Hope it helps,
Upt'North.

 

[jimbo66]

Hi,

Thanks for the suggestions, I brought it from a Honda Dealer, so they do a complete check over, the bike has only done 16,000m so it not really even run in yet. I will double check everything as you have mentioned. Thanks for the advice.

As for being scared!!! no way, After having my previous bikes I only mentioned due to this is the only bike that I felt at 70Mph unstable and with the known issues and other comments, wanted to know if there was something I could do about it.
I ride to the conditions of the road, wet slow down, dry and hot speed up.

Thanks again for all your comments

James

 

[T_C]

Just picked up my first PAN ST1300 (2005) on 12th November, I know there are more plastics on this type of bike than Michael Jackson face (RIP), after picking the bike up, and around 70Mph, the bike felt uneasy, weaving, unstable. I have seen that I could try removing the topbox, lowering the screen, fiddling with the rear suspension could help (I haven't tried any of these yet).

With no pillion, top box on and loaded, my ST will weave, it's not rare, but not at 70mph. No, you have to be in the triple digits. Pull the top-box or add in a pillion and the weave goes away.

The Honda topbox does have some free float, about 1/2" side to side.

 

[drbuzzard]

I've been up to 115mph with the trunk on and never experienced the mighty ST 1300 weaving

 

[flyfisher]

Just because you got it from a dealer doesn't mean they checked everything....tire pressures first, 42/42, are they worn? Secondly rear shock...crank it up (preload) and make sure someone didn't mess with the dampening screw.....good luck.......ff

 

[jonz]

You don't mention how worn the tires are. I had this issue with a Kawasaki Ninja a long time ago but only at *ahem* assertive speeds. A new rear tire cured the weave. Also, my 950SE will weave above 100 when loaded but not when empty (checked several times on a dry lakebed) - the rear squats a little when loaded which subtly changes the front end geometry so I'd advise checking the rear end sag. I personally hate riding with a top box as it changes the handling noticeably and only now will ever carry one if I need it for my wife. Lastly, the ST is picky about how the front wheel axle bolts are torqued - follow the instructions EXACTLY.

 

[Upt' North]

Jimbo and anyone who's interested in a bit of old footage on this subject go to:
You Tube and search on the Murray Walker recording on Wobble and Weave. It's a real eye opener on worn tyres, body weight etc and goes to prove that this isn't a ST thing. Wobble and Weave is as old as the motorcycle.
It seems the solution is to eat pie and fit new approved tyres. Not a bad solution when you think about it.
Upt'North.

 

[SMSW]

A couple of years ago, during the winter, I refilled my preload adjuster (rear shock). There is a great thread elsewhere here how to rebuild the preload adjuster - and if yours has not been serviced, 'cranking it up' may well do nothing to the rear shock because of gradual loss of fluid over time. At the same time, I read the Honda Service Manual, got overly clever, and eased off on the rear shock dampening thinking a slightly softer ride might reduce the bike's response to those raised ridges on some Interstates around here. On my first ride the following spring, I experienced instability in turbulent air (behind semi's) - it was very similar to riding my old Guzzi w/ bias tires on a milled roadway. After a suggestion here, I increased the rear shock dampening, put the preload back to the recommended position (by the Shop Manual) and my 'weave' or instability disappeared.

Since you bought the bike from a dealer, you might ask the service dept to test ride the bike - at 70 mph. However, if they don't want the responsibility of fixing it at their expense, they might come back and say the handling is 'normal'. There is a reason a lot of guys here call them 'stealers'.

Let us know what you discover - and what the fix is.

 

[T_C]

It's a real eye opener on worn tyres, body weight etc and goes to prove that this isn't a ST thing. Wobble and Weave is as old as the motorcycle.

Pan weave is an ST thing. It's a pretty specific set of circumstances. High mounted weight, top box, no pillion and high speed.

General wobble and some weave is also an option.

 

[jimbo66]

Hi All,

Just to keep you peeps in the loop.

After a long time messing around trying to understand where this instability was coming from, I have now sussed it... (for me anyway)
After checking all your suggestions, which helped (thanks).
My issue was very simple, it was that simple it was annoying....

My issue is the screen, when the screen is fully down, I have no instability issues at high speeds, which is very good news for me, as at least I now know the cause. As soon as I raise the screen about 1/3rd the bike starts to feel unstable, back end feels like it is slipping (I suppose you can call it wind buffer, with or without the top box).

So my thoughts...
Has anyone replaced their standard screen?
If I place a deflector on either around the base or the top of the screen, would anyone care to comment if this would work? Or get another custom screen (from MRA) that would allow me to raise the screen without any instability problems?

Thanks for your suggestions and help.

James

 

[Mellow]

I have the MRA spoiler on my Super Tenere and I can still get it to weave. There are a lot of factors. It's not just the shield, if you have any kind of wind blowing then it's all out the door as a different screen will only work for one scenario such as a head wind.

Stiffening up the rear suspension helps some.. but I've been able to get all my bikes to weave including GL1800s, VStrom, ST1300s and Super Teneres, even a Valkyrie.

For me, the best thing to do is reduce it so the MRA may help, i did have a laminar lip on my ST1300 but went to a the bike quip screen for better looks. Both worked well but only for allowing the shield to be a little lower than stock which is what you're trying to get to. They would still weave but on all the bikes it's been at high speeds and I just don't need any type of sustained high speed riding so I back off once I feel it and just settle into whatever speed the weather will allow.

Not sure if that helps much.

 

[Rekoob]

Good to hear.

I have a Clearview aftermarket screen that the PO put on and also added a vent about 1/3rd the way from the top. It seems it's a few inches taller and wider than stock (which I also have). I don't notice any issues with ether screen but will say the larger clearview does a nice job at blocking wind with minimal buffeting.

I normally ride with the clearview on just because the stock screen is hazed otherwise it would be on during hotter weather. I haven't found a way to make it clear again.

 

[JimGregory]

My 07 with very low miles was skittish at high speeds. Never noticed a wobble really, but trucks and wind had a large effect on it.
As you raise the screen I believe it also stands straighter up, More barn door ish.. I think. I installed a Clearview GT screen which didn't make much difference in any area, and even made a howling noise at high speeds. Then I installed some homemade windscreen stand off's, moving the screen farther forward and creating a larger gap between screen and fairing. This quieted things down. THEN I changed the angle of the screen, tipping it back more. This made a huge difference. I could raise the screen as high as I liked on the highway. Trucks and disturbed air had far less effect on me, topbox or no.
My thread on My issue. https://www.st-owners.com/forums/showthread.php?151713-Any-way-to-slow-down-the-1300-steering
There are others listed under windscreen mod or something like that.

 

[TomStickler]

The Pan can feel twitchy if the rear suspension is wound up. Contrary to urban myth, winding up the rear suspension pre-load does not make the suspension stiffer - it simply raises the rear end of the bike, which allows a heavier load to be carried before the suspension 'bottoms out' when riding over bumps. What raising the rear end will do is have the effect of moving the front forks towards the vertical - tucking front wheel under - which can make the bike feel much more twitchy.

We have a winner!!

I have proven this to my satisfaction by setting my McCruise, then reaching back to play with the rear preload knob. I can make it start to weave by cranking it up, and make it stop by cranking it down.

By raising the rear, the fork angle steepens, the trail decreases and the steering becomes "quicker".

 

[dduelin]

We have a winner!!

I have proven this to my satisfaction by setting my McCruise, then reaching back to play with the rear preload knob. I can make it start to weave by cranking it up, and make it stop by cranking it down.

By raising the rear, the fork angle steepens, the trail decreases and the steering becomes "quicker".

Unless the shock has been serviced the preloader doesn't do anything on most ST1300s until it's cranked nearly full hard and then it's barely doing anything. Two up riders on the stock shock are riding on the bump stop most of the time and max preload with a perfect preloader with a full 10 mm of travel barely gets the shock working in a usable range.

My ST never exhibited the Pan Weave under 120 mph or so but I'm not riding on the bump stop of the shock and I raised the ride height by 11 mm in the front which in itself slows the steering geometry. Weaving at 80 means something else entirely, I have to think The Weave and the weave here in this thread are not the same.

Seriously you are reaching down and winding up the preloader 30 clicks at a 115 mph or more?