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Discussion Starter · #1 ·
Today I was riding home in the rain. I have ridden a ton in the rain so it is nothing new. Going to a friend's house this morning it was not raining. I did 80 mph in a few places and the bike was rock steady as it always is.

Leaving his house, it was raining. I rode for about a half hour with speeds around 70 mph and very stable. THEN in an area of black top highway I got a severe wobble. I let up on the gas and it took some time before the wobble let up. I thought I was going to go down. So I eased myself to the center lane going slower about 60 (the traffic was heavy in that area) and it wobbled again but not as severe and finally I got to the shoulder to stop and look things over. I thought I had a flat but none.

Nothing makes sense. How could I ride for a half hour with no problem in the rain and then all of a sudden go into that wobble? The water on the road didn't seem higher than usual.

Later I was on concrete highway and the bike was steady again but I didn't bring it past 65 mph though.

I didn't lose any wheel weights. I can't figure it out.
 

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That is odd.
Were there any of those black tar strips they use to fill cracks?
I know I've ridden over those on Mopac and get an odd wiggle, not a severe wobble like you describe.
Sometimes, especially with the Bonnie, I think it helps to loosen your grip and let the bike shake it's head if it wants to. I think tightening your grip may have made it worse. That could happen when you get spooked and tense up.
Was yours to the point of a tank slapper? I'd check all your spokes (due to all the talk on here about spoke breakage). I checked mine and they seem fine. I ride an '05 790 with about 7500 miles on it.
That is weird indeed. Do you have any windsield on your bike? Could it be wind related?
I'm stumped. :???:
 

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BB,

The same thing happened to me about a year ago on a bitumin road.

The only thing I could put it down to was the speed I was going at, trying to do a ton, and the corrugation in the bitumin which really unsettled the bike causing me to have a major tank slapper!! scared the sh1t out of me.

I might also suggest you ride the road again in the dry, at the same speed, to see if it happens again and if it does you'll be ready for it this time. Hope this helps.

john
 

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Check for broken spokes, anything else on the front end that could have worked loose. Before I replaced my tires, I had a high frequency wobble if I took hands off. This was over time as my front tire wore out where yours started quickly.

Also check for tire damage.
 

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Discussion Starter · #6 ·
Good points.

My spokes were just checked and fine.
Tire pressure fine.
Wheels look good too.

It was not a tank slapper but a fast handle bar wobble. I did not tense and was thinking the whole way thru. I held the bars but not tight.

I avoid the tar strips on the road when wet. In this area though, the water seems to collect in the tire alleys due to it being concave there. I could not see the road close enough to see if I were running on tar strips with so much black.

It's the same section of road I've taken many of times. But next time when it's dry, I'm going to take that exact lane and see what that road is like on the surface.

Hard to believe I was hydroplaning with that small amount of water. SURE taught me a lesson about smooth black top roads though. That is more wobble than I ever want to deal with again.
 

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Discussion Starter · #7 ·
Check:

- rear wheel bearings and swing arm
A friend of mine has a tire changer. Yesterday we changed the rear tire on my bonnie.

If it were the bearings or swing arm, why would it have done it just in that area and not:

1. The 40 miles riding home after the wheel change? But it was dry then.
2. Riding this morning to the same house with speeds up to 80 mph on dry roads?
3. Riding for about a half hour on wet roads with speeds at least to 70 mph feeling rock steady prior to the wobble that then came.

You're right, I can't ignore this. I will check out that area of road again sometime in the near future. I may also bring my bike to the shop and have them do a check on it. It would be worth it to me.
 

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I bought new tires for front and rear, at a dealer, and they were both installed backwards! That led to some interesting handling.
I checked, and the direction indicator arrows on the tire were opposite what they should be.
On some tires, the tread is universal. On mine, it makes a difference, as I learned, quick.
I should learn how to do tires to avoid any other surprises from the "professionals".
 

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Discussion Starter · #10 ·
Bonafide,

Yeah, when you get to thinking that there is a decent chance of you going down if the wobble gets worse, it kind of makes you want to kiss the ground when the bike finally stops ok.

I also changed the rear brakes today. Still, when the bike is jacked up, the tire rotates fine. There is a slight bit of brake rub at a certain area of rotation, but nothing out of the ordinary.

BonneRocker,

I see you live in Austin. Please tell the dealer who installed your tires the wrong way so I know never to go there. Glad you caught that.
 

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I was dealing with a high speed "weave"..... weaving from one side of my lane to the opposite extreme, whoa!!! Turned out (as suggested above) my rear tire was put on backwards.

Other wiggles I've had
-I believe-
were a result of my sitting too upright with my weight bias too far back on the bike and no weight on my handlebars. This came to light as I was switching back & forth between different bars, risers, and aggresive seating positions.

I believe rear sets is a plus, lower handlebars help,
and....... well,
I gotta ask:
1) What kind of bars do you run,
2) standard 'mid' or rear sets,
3) tour pack on the back?
4) Do you have your tubes raised in the triple trees?
5) What kind of air pressure do you run?
6) Is there something about your riding style, personal weight distribution, and/or your seating position that differs when you ride in the rain?
 

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Discussion Starter · #12 ·
FattRat,

1) What kind of bars do you run,
answer: I have the stock bars with Gen-Mar risers.
2) standard 'mid' or rear sets,
-Standard
3) tour pack on the back?
-Yes, 40 liter H-P but at the time of wobble, not much in the bags.
4) Do you have your tubes raised in the triple trees?
-Not sure what that means.
5) What kind of air pressure do you run?
-38 back and 33 front.
6) Is there something about your riding style,
-At the time I was sitting upright at the front of the seat.
personal weight distribution,
-No weight on bars at the time.
and/or your seating position that differs when you ride in the rain?
-I only sit back and lean forward when there is a strong head wind and I want to tuck more behind my small fairing. It was not windy today but only raining so I was not supplying weight to the front handle bars.

Interesting questions, but, if I had the same riding position, speeds and equipment specs a half hour of riding in the rain prior to the wobble, why only in that one area?

But that area was not of few feet long; it seemed to be about a few hundred feet, considering how long the wobble was originally, then moving to the center lane at a bit slower speed (I don't know what exactly but faster than 55) then getting slight wobble even then.

I will say this, that wobble came on so quick that I am a bit Leary to go test ride my bike at higher speeds even on dry roads.

All your input is appreciated.
 

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I've experienced the wobble in curves at speeds greater than was reasonable , but it was dry and I attributed it to my windshield. How about hydroplaning? I've never experienced it myself but those who have say it is really scary.

Dennis
 

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I'm just another joe who knows nothing but what 35 years of riding has contributed to the right to sound like I know what I'm talking 'bout..... but I don't.

I'm gonna speculate that between the combination of road surface, direction of any wind, and your speed IN THE RAIN, combined with your stock bars equipped with Gen-Mar risers caused you to sit very upright, not to mention the standard 'mid' foot pegs contributing to less weight over the front end of the bike.
Combine this with a 40 liter H-P bag catching the wind and possibly upsetting the bike's aerodynamics in unique climatic conditions, and just enough water under the front tire to cause some hydro planing.

I think riding too fast for the conditions combined with lousy weight distribution and funky aerodynamics caused your foot print up front to disappear lofting the front tire.

I honestly believe that the way the bike is set up from the factory is just fine for speeds under 55 mph in a wind-free environment. Faster speeds beg for more weight over the front end, and crazy riding at high speeds by folk who drop the front end down a bit for a quicker turn-in should consider a steering damper. In other words, I think the standard Bonneville with a rider in an upright seating position is a recipe for unwanted wiggle under the right circumstances. The factory bars force the rider to sit TOO upright for the geometry of the bike.

But what do I know.....
I just sell noodles and TV's to inmates in prison.




:-D

[ This message was edited by: FattRat on 2006-12-24 09:04 ]
 

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It has been mentioned already but it sounds like just plain old hydroplaning. The water doesn't have to be very deep. Just enough for the front tire to ride up off of the road surface. Boom no traction.
 

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assuming everything about your bike is fine, there could have been a small patch of oil or diesel on the road. On a wet day with water all over, it would be hard to see.

Zaq
 

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Discussion Starter · #18 ·
First, please let me say that this issue has made me lose a decent amount of sleep last night, and I deeply APPRECIATE all of your inputs because I'm trying to make sense of this all.

Nor am I exaggerating any of this. That was a very dangerous situation that I can't get myself into again and I never want to see anyone else get themselves into.

I don't want to make this response long, so in brevity, reading what you have all said and FattRat's analysis, along with this great article about motorcycle hydroplaning http://motorcycles.about.com/gi/dynamic/offsite.htm?site=http://www.msgroup.org/TIP089.html,
it certainly makes sense that given the circumstances that I did hydroplane. Please read this article for all of your rain riding safety.

My experiences in rain led me to believe that it takes a high speed and a lot of water to hydroplane a motorcycle tire but I was wrong. Thank God, not DEAD wrong.

Along with what FattRat said about no weight on the bars and aerodynamics, as I remember that area of road, where the car tires traveled the road tunneled there, meaning the center of the lane and outer parts of the lanes were the high points.

I copied this from that article:

"By driving closer to the center of the lane than you normally do. Why? Because normal vehicle traffic actually cuts a trough into the pavement where the wheels ride. Those troughs are essentially where we motorcyclists normally track our rides. Obviously water depths are higher in these troughs."

Along with:

"(formula)....which shows that if your tires hold 35 psi, hydroplaning can be expected at 60.76 MPH,.."

I also remember when I got off to the shoulder to check my bike and then looked at the lanes, that the water in the road troughs look "sudsy" with all those cars running through it. So "snot" or an oily mix may have been contributing.

NO MORE GOING OVER 60 MPH FOR ME IN THE RAIN!!!

I will keep more weight up front and increase my tire pressure too if I know the conditions can be wet.

Thanks again for all of your sage info and caring hearts.
 

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I find the following very interesting, as I have asked the question but never could get an answer:

"By driving closer to the center of the lane than you normally do. Why? Because normal vehicle traffic actually cuts a trough into the pavement where the wheels ride. Those troughs are essentially where we motorcyclists normally track our rides. Obviously water depths are higher in these troughs."
I take it that the above is advising us motorcyclists to ride in the CENTER of the lane when it's raining? My question has always been, "...should I ride where I normally track my bike in the paths of the cars' tires that have gone before me, OR should I ride in the center of the lane where I see little water pooling, sometimes even dry, but where I know cars leak oil and/or coolant?"

Interesting..... and another question of mine was about air pressure in the rain. I have asked, "...should I run higher air pressure in an attempt to make for a harder/skinnier foot print to cut through the water thereupon decreasing my chances of hydroplaning?"

Once again, it seems your post (via that article I should go back and read) suggests that higher air pressure is desirable. I could never get any answers from the guru's of various boards, but now YOU have just come to MY aid. And for that, I thank you and of course wish us all a Merry Holiday and an upcoming season of MORE wisdom to be shared! (perhaps proving that Time magazine's "Man of the Year" may have been spot on, albeit a bit gay......)

Thanks!
:-D

[ This message was edited by: FattRat on 2006-12-24 10:33 ]
 

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Black-Bonnie,
Thanks for taking the interest in posting your experiences in the first place, and thanks to you and the other members for some very helpful info & link.
This is a great Christmas present for all of us. Maybe some lives are saved by this.
Happy Holidays
null

[ This message was edited by: MOBRIT on 2006-12-24 11:49 ]
 
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