High Speed wandering

[mshihrer]

Hey all,

So, I got my new rear tire on, and finally got to go for a ride. On the way home, was cruising down hiway 99 with the windshield about halfway up. As I started to approach 80 mph, the bike started to wander, kinda like when you get behind a tractor trailer. First I thought it was wind gusts, but there was no wind. When I got close to 100 mph (indicated on speedo, I think it's off a good 10 mph anyway) the bike was almost uncontrollable. So, then I set the windshield all the way down, and the bike felt better. My question is, is there an issue with the windscreen up high and at hi-speeds? Anyone else notice this problem? Also, I thought I read in another post about a manual setting, I guess there are two mounting positions for the windshield. Which is best? Thanks.

[nurseBob]

I'm still running the OEM Dunlops. I've had the bike to 125 indicated with the windshield up and had no issues (other than realizing I was out of my skill level).

[gstanfield]

Did not have any at all on my bike this past week, and I was acting pretty stupid out there. Here's a link to the thread about my ride (http://www.st-owners.com/forums/showthread.php?t=6122) where I ran flat out for several miles and had no wobble at all, if I had I would have slowed down immediately. I am running the factory Dunlops on my bike and have a 2003 with the non-electric windhield in the upper position.

George

[mshihrer]

ok, so it looks like I might have a problem. But, again, this was on the freeway, and there was traffic, so I'm wondering if it might have been turbulence created by the other vehicles. Keep in mind too, that on this particular stretch of freeway, most cars are traveling between 75 and 85 mph, I'm just trying to keep up, or just slightly ahead. I'll double check my tire pressures and such.

[nurseBob]

ok, so it looks like I might have a problem. But, again, this was on the freeway, and there was traffic, so I'm wondering if it might have been turbulence created by the other vehicles. Keep in mind too, that on this particular stretch of freeway, most cars are traveling between 75 and 85 mph, I'm just trying to keep up, or just slightly ahead. I'll double check my tire pressures and such.
I was in your neck of the wood not long ago and cruising in the 75 - 85 range with trucks etc.; I don't remember any handling issues. I think you'd be wise to check things out.

[IntruderCruiser]

what brand of tire?

used to be a great place in Bakersfield for motorcycle parts, but I believe that Pat Ryan bought the Kawaksi dealership and shut down his Bakersfield Motorcyle Parts

[Blrfl]

Do you have a top box? Honda doesn't recommend going any faster than 80 with one, presumably because the wind catches it and takes weight off the front wheel.

--Mark

[Burger]

Many years ago I had a Kawasaki GPZ750R. For it's time it was one of the best handling bikes available and in comparison to anything else you felt like you were riding on rails. Then I changed the tyres... at anything above 60mph the bike felt like it was floating, wandering, drifting and that the wheels would slip out from under me at any second. I had the wheels balanced, the tyres checked for roundness and deformities etc etc. Nothing changed it. So then I swallowed the cost and swapped the tyres again for a completely different make and the crisp, fine handling returned. No idea to this day what was really wrong, but I believe from this that some tyres simply don't suit some bikes even if they are the correct size etc.

Regards,

[crazykz]

I ride with the windhshield up most times and I've had this issue since the day I got the bike on the Bridgestones and now with the Pilot Roads.

Curt

[Mongo]

135 MPH, shield all the way up (ELECTRICALLY), in the upper of the 2 manual settings, OEM Bridgestones, the faST blue (of course), solid as a rock. Might want to check alingment of your rear wheel/axle. just my 2 cents.

[pdfruth]

ok, so it looks like I might have a problem. But, again, this was on the freeway, and there was traffic, so I'm wondering if it might have been turbulence created by the other vehicles. Keep in mind too, that on this particular stretch of freeway, most cars are traveling between 75 and 85 mph, I'm just trying to keep up, or just slightly ahead. I'll double check my tire pressures and such.


Mine is rock solid up to 135 (indicated).
Do the same test again, in clean air, no rain grooves (did the freeway have rain grooves), tires at 40 - 42 psi.

[mshihrer]

some sections of 99 do have rain grooves. But there are also sections recently repaved. It did it on both section types. I have stock Dunlop tires. Only 1200 miles on the front one, 100 miles on the rear one. It is possible it is the road, because I have ridden other roads at those speeds and never felt that sensation. Still, gonna recheck everything.

[Doobage]

Had my bike up to 115(i) this weekend. Right at about 100(i) it felt a little floatish, but above 105(i) felt like it was better. I didn't stay there long, probably only a minute or two.

[wjbertrand]

I've had mine up to a true 120 a few times, both on the OEM Dunlops and the current Avons. Never noticed any level of instability like you describe. Make sure your tires are all the way up to 42 PSI each and that you have the proper amount of preload set out back. I've noticed that the 1300 gets a little squirrely if the rear shock is set up too soft. I think it lets the wind push the bike up and back, taking too much weight off of the front wheel.

[crazykz]

This is all interesting as I've had this issue with mine on the Bridgestones and the Pilot Roads. I get it around 80-85 MPH and it does the same thing that is described here about it feeling like your catching the wake behind a truck. It's done it since day one with 4 different sets of tires and I'm pretty sure I'm assembling everything correctly. Can't imagine I would do it wrong 4 times but I suppose it's possible.

Curt

[IntruderCruiser]

Some Dunlops had a problem -- might check it oout

[mshihrer]

I've had mine up to a true 120 a few times, both on the OEM Dunlops and the current Avons. Never noticed any level of instability like you describe. Make sure your tires are all the way up to 42 PSI each and that you have the proper amount of preload set out back. I've noticed that the 1300 gets a little squirrely if the rear shock is set up too soft. I think it lets the wind push the bike up and back, taking too much weight off of the front wheel.
This COULD very well be the problem. I'm a pretty heavy guy, about 250, and I have the spring loading at the softest setting. Makes sense that this way the front end could get light. Gonna try stiffer setting. Thanks.

[Scaredy Cat]

I find that fully loaded (i.e. over-loaded), two-up, with screen fully up, I get a weave above 125. I've done a lot of autobahn miles and I'm sure it's the screen that does it. Doing that speed with the screen down is uncomfortable though.
I'm pretty sure my bike is straight (4000 miles, and she's done it from new).
I always ride with the topbox, but when I'm going fast on my own I keep the screen down. I'll try it topboxless, solo - I never saw it as much of a problem though, "nature of the beaST" and all that)...
:-)

[805gregg]

It's like the sound barrier once you are past it no problema, it's just testing your huevos. All kidding aside if it wobbles shut it down, you've probably seen the guys at the salt flats, it starts with a wobble and ends in a crash. Mine wobbled at about 137 indicated in the desert, but later in central cal I got to 135 gps no wobble, maybe side wind?

[nisbeam]

I am running Metzler Z6s and have experienced this problem both with these and BT020s. The problems are now completely gone, and the reasons were (in reverse order of importance):

3. Tyre pressures a bit low - need to be 42psi
2. Rear pre-load was set too soft. This made a BIG improvement when raised.

and the number 1. cause... rider input. Much more noticable with the screen up, I did not realise at first that I was in a bubble of air - BUT was still being buffeted slightly by crosswinds. Not being held back by wind from the front my upper body movement were slight but transfered through to the bars. The trick is to try to keep a very light grip (more of just a touch if that's possible) on the bars, and no more wobble.

I have even done this in 50mph+ buffeting crosswinds, and just let the bike sway about underneath. It will track straight & true if you can avoid that rider input. Easier said than done when you're nearly getting blown off, but just grip the tank with your knees.

Hope this helps.

Oh yes, my bike also slips through the air better because it is silver :D :03biker:

[mshihrer]

I am running Metzler Z6s and have experienced this problem both with these and BT020s. The problems are now completely gone, and the reasons were (in reverse order of importance):

3. Tyre pressures a bit low - need to be 42psi
2. Rear pre-load was set too soft. This made a BIG improvement when raised.

and the number 1. cause... rider input. Much more noticable with the screen up, I did not realise at first that I was in a bubble of air - BUT was still being buffeted slightly by crosswinds. Not being held back by wind from the front my upper body movement were slight but transfered through to the bars. The trick is to try to keep a very light grip (more of just a touch if that's possible) on the bars, and no more wobble.

I have even done this in 50mph+ buffeting crosswinds, and just let the bike sway about underneath. It will track straight & true if you can avoid that rider input. Easier said than done when you're nearly getting blown off, but just grip the tank with your knees.

Hope this helps.

Oh yes, my bike also slips through the air better because it is silver :D :03biker:
just found my front tire at 25 psi, rear tire at 35 psi. Thanks Fred Cummings Honda Center, Bakersfield. Also, just found a real nice gouge in my rear wheel finish, just had new tire mounted. Thanks again, Fred Cummings Honda Center Bakersfield. I may have also been putting some slight input into the bike as well, I was kind of on the tired side and was rushing to get home. I'm sure all is going to be good from now on. thanks all.

[IntruderCruiser]

quite frankly, take it back and complain -- there is no reason for that type of service

[msev111]

I ride w/top box usually too. A few days ago I took it off and went for a ride on I287. I could DEFINITELY tell the difference; front end was much more planted. Not even at high speeds, just 75 to 80.

[nisbeam]

Just posted this on the other "weave & wobble" thread...

kaipan - glad to hear you're happy now it's a great bike when the set-up is right & such a disapointment if not, so thanks for the good news.

The top-box extra weight is further out over the back wheel than extra weight in the panniers, so can potentially be more of an issue. I think the real problem is that the extra weight requires more pre-load on the rear shock to stop sagging. If you dont do this, the rear sags, the front becomes light & you get both the inherent weave and also of course the front will be even more succeptable to (unwanted) rider input.

I think you're correct about the rear shock. A friend of mine (over 300lbs) and his son were unable to get the bike to handle well & it was an issue on a recent touring holiday - had to keep the speed below 50 to avoid the wobble & weave.

It's OK for lightweights like me, but is you are on the bigger side (including passenger & luggage) I think a stronger spring is in order.

But how about this idea Honda ? - Time to invent automatic sensing pre-load setting - like self levelling suspension. The auto bit could do the main work keeping the bike handling sweet & our manual pre-load adjustment could fine tune the stiffness at the rear. Go for it Honda - you know you can do it !

:03biker:

[duane57]

Mine does the same thing at 125 starts to weave with windshield all the way up. If I lower it down steady right up to 135. Im 6'4" 265lbs and have spring set hard and dampinging to nearly 5. I believe its a combination of two things the windshield acting like a big wing and lightening the front end and the bike being softly sprung in the rear. Duane

[Kempo-STer]

Same here with Top BOX on...

Hit 80 and she started to dance....

I fixed it this way..
Preload was WAAAY too soft. stiffest setting now all the time..
Relaxed my grip on the bars..Higher speed = higher wind on arms = unwanted input to the bars..(Since you going faster, I may have subconsiously tightened my grip)..I relaxed and could really feel the difference..

Sometime she still displays some symptoms of this but the wind is usually is always kicking hard when this happens..

[CruisingDog]

Do you have a top box? Honda doesn't recommend going any faster than 80 with one, presumably because the wind catches it and takes weight off the front wheel.

--Mark

I recently [last week] rode with a Honda Top Box and didn't have any issues at 100 MPH! Actually it got a bit too quiet and comfortable at times! I was out in the open plains in AZ and there were occasional cross winds but nothing to write home about!

So here's a peice of very good advice I got from a BMW LT rider. Apparently the BMW handbook meantions putting all your heavy stuff in the lowest position in your panniers. They also talk about balancing them out properly. For 2 reasons.

1) C of G is lower which means the bike will handle better in the twisties
2) The bike won't pull to one side. Don't forget, your rear wheel is a Gyroscope when you travel above 30-ish MPH.

3) OK, I said there were 2 but there's another side effect; Wrist strain. Typically you'll have to put more pressure on the handlebar on the opposite side of the loaded side because you'll need to counteract the weight.

4) Yeah, another one. Improperly loading also causes tires to wear unevenly.


Very good advice from a fellow rider. You see, some BMW guys are pleasant! :-)


It might be worth thinking about how your bike was loaded since a heavy pannier could do exactly what you describe.

[clmixon]

There are probably a lot of causes. I wanted to reassure those who have a wobble that they are not imagining it or assembled wrong, heres why.

On the Texas trip I was loaded at the same weight every day, same stowage poistions, same preload ( almost all the way in) and so forth. At about 80 on I-10 the first day I had the wobble start, nothing too serious, easy to counteract but it was there.

Next day heading N. from Van Horn we went this speed or even more (figuratively of course for any LEO's) and I did not have any wobble at all, even hands free to take a picture.

On day 3 and 4 no wobble at any speed, but on day 5 it came back with a vengence. About the same weather every day, same temps and so on, windshield in multiple positions did not have any effect.

I did have to add air on day 6 5 pound low front and 6 rear. Had a wobble for a while on Friday going east and none on Saturday.

Dunno, I just live with it, it is not that bad when it occurs, just gets my attention that there are some inputs going on that I did not make.

I do not have a Hondaline trunk though, mine is the 52 L Givi. I am running a set of Bridgestone 020's with about 4500 on the back and 4000 on the front.

Chris :04biker:

[Peter]

By Design The Honda topbox is designed to go from side to side on the mountings located underneath the plastic covers (seen with the topbox removed) try spraying them with some silicon spray or similar. In doing so the box should now go from side to side more freely....this seems to have a positive effect on the high speed wobble

Try it what have to lose accept your sanity as some ask you why you are greasing up your topbox

Regards

Peter

[gottaride]

This COULD very well be the problem. I'm a pretty heavy guy, about 250, and I have the spring loading at the softest setting. Makes sense that this way the front end could get light. Gonna try stiffer setting. Thanks.


Crank up that pre-load (and I mean closer to the top end than the bottom...probably about 5 clicks from the top to start) and you'll have a brand new machine. It's virtually unrideable at your weight on the softest setting.

[Doobage]

Wobble, I noticed it for the first time this last weekend and I've had two significant changes to the bike that could be the culprit. (which I'll describe in my ride report).

Since it's an '03 with a fixed windshield, I know that it wasn't the windscreen. About 3 weeks ago I added some Dunlops (not sure if they are OEM) and still haven't found how to determine that, with the exception of a recent thread that says the "plys" are different. But how do you determine that without cutting the tire apart or wearing it down? There MUST be something written on the tire.

The other addition to my bike is a large luggage rack 2.5 ft X 1.5 ft that sticks off the back and looks something like a cookie sheet.

I've noticed that since I have added that, going fast 85i-95i, the bike dances as if you were in a tractor trailer drag wind. But up over 95 it seemed to stabalize. It wasn't severely bad, but enough for me to notice and realize that I didn't like it.

I suspect anything that alters the wind flow will have an impact when you reach higher speeds. I haven't tried stiffening the suspension, which may help, because it is probably the wind coming over the bike and depressing the rear wheel.

I suspect a poorly mounted wheel would reveal itself at all speeds and become more prominent at higher speeds...but that's just a guess.

[Kempo-STer]

Hey Mid..
I've got MCL risers on and don't think it has an impact on any wobbling effect. I'll tell what it DID do was really nuetralize any added weight to the bars and MAN did it make steering input so much easier and quicker. Since your upright and any weight is not on the bars, a lot less intput is needed on either bar and she dives into a turn. Very good!
People are also talking about weight..I'm in a 265 so i am no lightweight either..
Biggest thing is relax the arms/grip and Preload to stiff..

Oh BTW I put the Calsci belly pan on for the winds and added stability and it SEEMS to have made a difference as well. Could be my imagination trying to justify spending 30 bucks on it..But it was only 30 or so dollars...

Have fun and ride safe..
Kempo Todd