Another high speed wooble accident

[LeeWonnacott]

All that said, it's clearly true that the 1300 police bikes have a real problem with high speed weave.

Well, I've ridden over 16,000 miles in the last 90 days, in ALL weather and road conditions and usually fully loaded. In another thread about crossing the St Johns River at Jacksonville I was somewhat admonished here that my observations about a wobble or weave were probably incorrect.

Here's what I think after considering it fully... and observing a phenomenon of the ST1300 several times now. It WILL weave at speeds above 70 MPH when fully loaded with the windscreen down IF you are following another vehicles draft at the right spot. The first clue is a minor buffet following by the weave. It's a gentle movement, but if you have some crosswind buffet it CAN get out of hand if you are unprepared. I suspect the rider in question simply had his attention elsewhere when the weave started, he over corrected and induced the wobble himself.

Before you start throwing rocks at me... look again at my first sentence. I've LIVED with this bike every day for the past three months. I think it's the finest touring machine I've ever had. As a sport machine... can't tell. I've never had a sport machine and probably never will - I don't have the desire to drag a knee or toss the thing around the corners like it was stuck to a rail. BUT, I must admit, I've been on so many mountain roads lately and the thing rides so nicely that I must might find an available track day and take an advanced course just to explore those performance corners.

Back to the weave/wobble. I've noticed this even when some mini-vans are ahead of me. And with big trucks it's there sometimes and sometimes not. The effect of the wind stream seems somewhat lessened by the position of the windscreen - a high position seems simply to move the entire bike rather than induce any weaving motion. AND, I have actually practiced altering my seat position in these conditions. When I know I am entering a draft situation I can lessen the movement just by locking my knees to the tank and stiffening my upper body as I slightly relax my grip on the handlebars. It helps.

I think the ST1300 is VERY susceptible to even minor changes in your body position. Try this on your next day out. Pick a lonely road with a smooth surface and no traffic, of course. At about 40 mph just let the throttle drift down... or lock the throttle, and take your hands from the bars and sit upright on the seat. You are in balance almost immediately ... now drop a shoulder - doesn't make a difference which one. The bike will move accordingly... you can gently weave back and forth across the lane just by moving your shoulders.

If we all keep in mind that body position, wind buffet, angle of lean, and TIRES each have a significant affect on how the bike moves we will be better off - and better riders. Tires? Yes! I've seen a great deal of difference between the Dunlop RoadSmart and the OEM Bridgestone. Once the RoadSmart gets over on the side of the tire and into the different compound area it turns into a VERY sticky tire and much more willing to grip the road in all conditions. I'm actually beginning to ride into corners more aggressively just so I can be assured of better grip... but the down side of that is that even a small amount of gravel or debris will slide the rear tire very fast!

As to avoiding that 'weave' I see ... I worried at first but now I don't - it's a normal condition, at least for me and my bike. I just anticipate it and if the condition seems to get worse I just back off and bit from the draft or slow down. This should be how we ride ANY bike, regardless of the manufacturer or model - know how it reacts, don't be macho and say you can handle, be practical and explore the potential problem and KNOW you can handle it.

Leaving Monday for another 7,000 mile loop. Going through WV to PA and through NY to Maine and then back through New England states MD and VA.
Any of you want to ride with me for a few miles just send an email or PM.

Lee

 

[Randy Bowers]

Yes, glad the guy is going to be OK. I,ve had the V-65 Magna and Sabre and for the first year that I had the Magna it had a wobble that would start at 110 riding solo, 120 riding two up. Well I finaly found the problem- the rear wheel had lost a weight. So I agree with the Too Many Variables point. Having these bikes led me to buying the ST, and I love it, and as I've said in other posts this one has been to 142 indicated, sitting upright smoking a cigarette. By the way the Sabre was steady to 155. If it were the bike itself, it would happen to us all.

 

[FJRHank]

Just did a google search on "rake and trail st1300", here's an excerpt from one of the results:

05/02/07 The results of the Coroners Investigation --------> http://news.bbc.co.uk/1/hi/england/merseyside/6600897.stm

Notice that the article refers to a "high speed weave", NOT a "speed wobble". Speed weaves result from the rear tire having a lot more grip than the front tire. Or the front tire not having enough grip to stabilize the chassis. All two-wheeled vehicles will speed weave at some highway speed, and, if the rider wants to cruise at very high speeds, he needs to pay attention to the weight distribution and the front tire profile, as well as front spring preload and the weight of the fork oil. Part of the ST1300's problem may be the extra police equipment over the rear wheel. The weight distribution shifts and the center of gravity rises. The front tire has even less grip than before, while the rear tire has more grip. The front tire has to work a lot harder to stabilize the motorcycle and it fails to do so. A perceptive rider will notice that the handlebars seem to waggle a bit more and the motorcycle seems to be rocking slightly from side to side. The solutions to speed weave include mounting a less pointed front tire, dialing off fork preload, and reducing rebound compression to let the tire grip the road better. Also, if the forks can be pulled up in the triple clamps by around 10 or 12 mm, the speed at which speed weave begins will be raised significantly, at
the expense of heavy steering in parking lots. Once you shift the weight balance a little to the front by pulling the front forks up through the triple clamps 20 mm, the speed weave will vanish, but, the motorcycle's steering will become heavy at low speeds.

The chassis engineer has to compromise between light steering at slow speeds or high speed stability. I guess they figured most people want that "sporty responsive" steering feel all the time even at low speed. After all the ST1300 is a Sport Touring Bike. It makes sense if you look at it that way.

Kawasaki's original Z-1 didn't use very much rake or trail, perhaps 3.25 inches. This was in the interest of light steering at low speed. But, when racers experienced "wobbling" and general foul handling at very high speeds, and bracing the frame didn't help, Kawasaki and other Japanese manufacturers responded by building chasses that had as much as 6 inches of trail. Of course, the professional racers who rode such machines were never going to try to ride them in a parking lot... Steering dampers prevent "speed wobbles". The problem with the ST 1300 is rightly understood as a *high speed weave*. "Speed wobbles" are something else, entirely. Speed wobbles occur when the motorcycle is in the vertical position. They do not throw the rider off the motorcycle, but they scare him. In the case cited, the constable was thrown off his motorcycle and a car ran over him.

Speed wobbles occur when the front tire contact patch is unweighted while crossing bumps, railroad tracks, etc. The speed wobble occurs at such high frequency ( 5 ~ 10 cycles per second ) the rider has no time to react, and the speed wobble is over and done with. When the front tire regains traction, the energy of the speed wobble is absorbed into the chassis and the oscillations are quickly damped by inertia. A steering damper will not prevent a high speed weave, because a high speed weave involves more than just the oscillation of the forks around the steering spindle.

High speed weaves tend to occur when the motorcycle is leaned over in a turn. High speed weaves involve the whole chassis, so the oscillations around the roll and yaw axis occur at a much slower frequency (about 1~3 cycles per second). The amplitude of oscillation in the pitch axis is very small, because the steering head jacking effect of waggling forks is small. But the amplitude of the oscillations about the roll and yaw axis is absolutely terrifying. The rider can get out of the speed weave by leaning forward, rolling off the throttle, and dragging the rear brake lightly. A rider can also stop a speed weave by dropping his feet off the footpegs and lowering the center of gravity, but he risks running over his foot if the roll oscillations are extreme.

The ST1300 police model has a high center of gravity, and the front tire lacks enough traction to stabilize the chassis. A lower profile, wider, or less pointy front tire is indicated. Or, a narrower rear tire might be fitted to stop high speed weave by reducing traction at that end of the machine.

----------- end of quote ----------------

It seems like the most telling thing mentioned is the balance the designer makes re rake and trail. We've all noticed how easy it is to turn the ST in, "once moving you don't even notice the weight"...

I think they designed it a bit too aggressively. And the yamaha fjr has been said to be "slow to turn in", but it doesn't have a weave / wobble issue.

regards,

 

[bmcdonau]

Dayum.

I wish we could get a "collective body of knowledge" about this. I mean first person type, not "I heard..." or "The article said..." or "I read on the internet..."

We all know that the ST's we ride are rock solid. At least mine is and the ones I ride with are. What are the variables? Tire pressure? Tire Condition? Loading? Aerodynamics?

For every condition I can think of, I can already think of an exception. I mean, I've seen George and Mac on the road with tires lashed on their other stuff I've been known to ride a tire until just before the air shows...

What causes the condition?

There are plenty of members here who have experienced the wobble first hand. It takes just the right road, load, wind, and speed to induce the wobble. I had it happen to me once at 120 mph with a passenger, top box and pretty stiff breeze out of the front right quarter.

The bike is indeed unstable in "some" conditions. Luckily, in my experience, it doesn't just jump right into a tank slapper, but starts as a gentle weave back and forth which increases as speed increases. As I've said before, the bike is not unsafe, only an idiot would keep increasing speed in the face of a bike weaving back and forth.

I've had it all the way up to 150 many other times and it felt stable as a rock. just be aware, just because yours hasn't done it yet, doesn't mean it won't do it ever.

I don't normally jump on the throttle and hit top speed as fast as I can when I ride fast. I just accelerate normally and wind it out to 7000 rpm in each gear. It takes me awhile to get to high speed. I think cops have problems because they are probably responding to an emergency or in pursuit when they have problems. My theory is they blow right through the "gentle weave" part and hit tank slaper speed.

I'm sure the police departments who had accidents had many other isntances where their officers rode the ST above 100 mph with no ill affects.

 

[bmcdonau]

Here's what I think after considering it fully... and observing a phenomenon of the ST1300 several times now. It WILL weave at speeds above 70 MPH when fully loaded with the windscreen down IF you are following another vehicles draft at the right spot. The first clue is a minor buffet following by the weave. It's a gentle movement, but if you have some crosswind buffet it CAN get out of hand if you are unprepared. I suspect the rider in question simply had his attention elsewhere when the weave started, he over corrected and induced the wobble himself.

Lee, you described what I felt to a tee. It only happend once in 16,000 miles and it wasn't dramatic, but the bike was slowly drifting back and forth. I was following a friend on his wing and was probably 50 feet behind him.

 

[LeeWonnacott]

Lee, you described what I felt to a tee. It only happend once in 16,000 miles and it wasn't dramatic, but the bike was slowly drifting back and forth. I was following a friend on his wing and was probably 50 feet behind him.

Dennis - thanks for the affirmation, especially that it doesn't take a big vehicle to induce the problem. If we could wind tunnel test the bike in various configurations we would likely find there is some swirl position that plays havoc with the bike. I've just gotten used to it and will usually just pass the problem or somehow move away from that part of the wind stream.

As our teachers used to say all of the time - "Knowledge is Power!"

 

[Randy Bowers]

In regards to the light front wheel, what about a wing atop the finder. I've seen these on some other bikes and at speed they can create a fare amount of down force. ??

 

[mjhenne]

I keep my front tire glued to the road by consuming mass quantities of road crushing PIE.

May I recommend the oscillation dampening cherry?

I'm probably 235 geared - wonder if lighter riders have more of an issue with stability? A lighter rider no matter with a passenger or load will certainly have a different front to rear weight distribution than a heavier rider.

 

[suedez]

Was the windscreen up or down? My ST seems a lot happier at high speeds when the windscreen is full down.

 

[tommyboy]

Now that's a great idea- eat more PIE to save our lives! In seriousness I was wondering about the larger than stock windscreen (I won't complain about Cee Bailey because they make a great product and they are right down the street from work). My ST is much happier with the screen down. I think someone sells "tuning blocks" to change the angle on the windscreen. I wonder if it helps.

 

[stovepipe]

.....opcorn

 

[psquiggs]

I am sorry this guy crashed...but

the person who posted this story seems very upset as I would be also. My own experience is that I have never experienced a wobble. Last summer I did a 7000 plus mile trip loaded to the gills with stuff. Full top box, loaded side bags, tent and camping gear on the passenger seat, tank bag loaded, both side pockets full and my fat ***. I was pushing 3 bills at the time. I hit speeds in excess of 140 MPH in WY. I also cruised in the 90 to 100 MPH for hours on end. Sorry but I don't get it.

 

[Marshal_Mercer]

Now that's a great idea- eat more PIE to save our lives! In seriousness I was wondering about the larger than stock windscreen (I won't complain about Cee Bailey because they make a great product and they are right down the street from work). My ST is much happier with the screen down. I think someone sells "tuning blocks" to change the angle on the windscreen. I wonder if it helps.

Hi, Tommyboy:

Two comments:
1) Although "tuning blocks" are available, they are not really needed. Mounting the windscreen in its upper mounting position angles back the screen sufficiently to prevent most of the oscillation producing by wind-loading at the base of the screen. Yes, I did the primary research on this;
2) making more firm the damping on the stock rear shock, or replacing the shock with something more robust, markedly diminishes weaving, especially when in "dirty" air.

I'll be gone to Canada for about ten days, starting on July 1. Why don't we try to get a ride in after that. I'm in West Covina.

Marshal

 

[tommyboy]

I saw something similar to what the poster is telling on a GL1500, but, as it turns out, his rear tire went completely flat because his angled stem came loose. He thought he had lost the front end. It as only after he stopped (safely) that we found the problem.

 

[bmcdonau]

I am sorry this guy crashed...but

the person who posted this story seems very upset as I would be also. My own experience is that I have never experienced a wobble. Last summer I did a 7000 plus mile trip loaded to the gills with stuff. Full top box, loaded side bags, tent and camping gear on the passenger seat, tank bag loaded, both side pockets full and my fat ***. I was pushing 3 bills at the time. I hit speeds in excess of 140 MPH in WY. I also cruised in the 90 to 100 MPH for hours on end. Sorry but I don't get it.

Glad you haven't experienced it. It starts out mildly disconcernting and if you don't acknowledge it by slowing down it can become catastrophic. I'm not sure what you mean by "Sorry but I don't get it". Do you not understand how it can happen, or doubt that it does?

Police departments on in Europe and Africa have lost officers in high speed accidents linked to the weave. I'd bet it happens very infrequently when you consider how many Pans or STs are in police fleets and how often they are ridden at high speed.

Ride magazine (published in England) loaded up a Pan European with sensors to measure side to side aerodynamic forces and movement and after some experimentation were able to make the Pan weave at will without maladjusting the suspension or underinflating the tires.

Several of our ST-owners.com members have experienced it first hand.

It's done it to me once in 16K miles so the odds are most of owners will never experience it in person which is a good thing. But, that doesn't mean it isn't real or it won't happen.

 

[tommyboy]

Marshal: I will be in Port Orchard, WA starting on July 4 for a week. I can get back on the bike when I return (doctor suggested I stay off it for a month, but that was another post - I will learn how to stop and put my RIGHT foot down first!).
I never ride fast enought to need the Penske shock you have, but I would love to head off to Julian or Mt. Palomar again!

 

[kanem]

The boy's definitely got a problem.

 

[bmcdonau]

The boy's definitely got a problem.

Mike, I'm not asking you in particular, but your post is the last one addressing Hammick's attitude on the Adventure Rider forum so I'm placing this here. I read the thread and didn't think he flew off the handle. He is just a upset about his friend and is asking the same questions a lot of people on the internet have asked before in regard to the ST and wobble/weave. What did he say that makes you say he has a problem?

 

[Burger]

First off let me say that any opinion and experience I have is purely mine and I am not voicing my experience in any official capacity as an admin of this great forum. I want to say that up front because there are some that might be a little shocked by my words but I hope you'll read them accurately and therefore understand.

The Honda ST1300 has many fine attributes and to my eyes is a very good looking bike but I will never ever own another in its current design. I have owned many different bikes over the years and no other ever gave me the, quite frankly downright scary, at times, feelings of vagueness and complete unpredictability the ST1300 did.

Someone has already stated that the weave, the one that can easily kill you is nothing like the instability felt from the wake of trucks etc. and I can tell you first hand that it's not. They are nowhere near the same thing. So when you read about the weave, please don't think you know what it is if all you've felt is some turbulence from other vehicles.

Yes, all motorcycles will weave to some extent if they're not loaded correctly or the tire pressures aren't right etc etc. But no other bike I'm aware of will send you into a life threatening situation if it isn't set up 100% accurately for you - especially when, it's been proven time and time again that while set up might affect the point at which the ST1300 will weave it will absolutely not guarantee it won't happen. It never ceases to amaze me when this subject comes up how many 'experts' start to post about suspension set up, saddlebag loading, tire pressures etc. and how many then pipe up with I've had mine to 175mph and it's rock solid. You're all missing the point.

The life threatening weave the ST1300 can put you into can occur at any time, any place, any settings, any tire pressures with NO warning. It can happen one up, two up, screen up or down, tires right, over or under inflated, shock pre-load wound up or down, top box on or off or any other combination you can imagine. There is no logic to it. You can ride a section of road at 130mph one day and have no issue and ride the exact same section the next with the same configuration the next day at only 70mph and experience a weave. If you've never experienced one then you're lucky... but lucky for what? Who knows? Your build, your posture, your set up? Something they got right or wrong when they built your bike? NO ONE KNOWS or at least the one's who do are not telling us.

And THAT, the unpredictability and inexplicity of it are THE PROBLEM. You might not have experienced the weave, but you cannot deny it exists because I have and I know others who have. Honda are well aware of it but refuse completely to admit it or provide any explanation because they couldn't handle the law suit and so rather they are happy for you to sit on a time bomb that could one day kill you.

So, should you all run out and sell your ST1300's? I don't think so. It's a fine bike in many other respects and if you've never experienced a weave the law of averages says you probably never will. Just don't belittle it, think you can explain it or bury your head in the sand... none of these will do any good either and you cannot, no matter how good you think you are, explain it.

It's real and very frightening.

By the way, experiences from those on ST1100's are pointless in this subject... the 1100 didn't weave but then it also doesn't have the aggressive rake of the 1300.

I love the community here on ST-Owners because despite that being my experience of the ST1300 as many longer term members are aware, they're still happy to have this somewhat odd Brit as an admin. If however, anyone feels I've overstepped the mark or should not be welcome here because I believe the ST1300 is the most dangerous bike on the roads today then I'll hand my resignation into Joe. Joe, you know my experience and feelings on this so of course, feel free to pull this post if you prefer.

I don't want to scare anyone and I don't in any way want to damage this great community, but please, please stop thinking this problem doesn't exist or that you know the cure... it does and you don't - I tried them all.

Regards,

 

[GregSTer]

One responder on this thread had this comment: "I think the ST1300 is VERY susceptible to even minor changes in your body position. Try this on your next day out. Pick a lonely road with a smooth surface and no traffic, of course. At about 40 mph just let the throttle drift down... or lock the throttle, and take your hands from the bars and sit upright on the seat. You are in balance almost immediately ... now drop a shoulder - doesn't make a difference which one. The bike will move accordingly... you can gently weave back and forth across the lane just by moving your shoulders."

BOY -- I wish mine would behave this way. If I lock down my throttle and take both hands off the bars my ST1300 imediately begins moving to the right. It can be compensated for or steered by excessive body English, but can not be held in a straight line.

I've never experienced tank slappers on my ST1300, but have experienced that on other machines -- no fun. I do ride in a lot of challenging wind conditions, I am convinced that the aerodynamics of the bike are such that it leans into wind, and if a rider does not try to control it, it manages wind very nicely. If one attempts to control the bike when it is responding to wind, then it begins to be a bit unstable. This might be at the root of many of these wobble and weave reports we see.