High Speed Wobble

[MSGU1-4936]

I have never experienced a high speed wobble until this weekend. I was out on the bike on a stretch of highway when I opened her up and off I went at one point the bike started to wobble, scared the shit out of me. I have never experienced this before, I rode most of the day cruising between 70-85mph. There was a lot of high cross winds this weekend and even at 70-85mph I would have to counter steer to get back on track. At what speed should I be experiencing this high speed wobble. Not sure if the wind was a big factor or there is a problem with the bike, like I said I have never experinced this before and I have opened her up on this same stretch of highway without any wobble.

:ummm:

 

[maxcruiser]

I have never experienced a high speed wobble until this weekend. I was out on the bike on a stretch of highway when I opened her up and off I went at one point the bike started to wobble, scared the shit out of me. I have never experienced this before, I rode most of the day cruising between 70-85mph. There was a lot of high cross winds this weekend and even at 70-85mph I would have to counter steer to get back on track. At what speed should I be experiencing this high speed wobble. Not sure if the wind was a big factor or there is a problem with the bike, like I said I have never experinced this before and I have opened her up on this same stretch of highway without any wobble.

:ummm:

Might be time to have a look at your steering head and swing arm bearings.

A well set up bike is good up to 120+ mph before wobble, but there is of course many factors that can create a wobble at different speeds, crosswinds, bumps or wallows in corners, sitting geometry, etc....

I had it happen twice on a vmax - once at 120mph on a wide sweeper corner with a wallow in it and the other time was on rapid decelaration at 120 or so mph - both times I managed to get out of it safely, but scary shit :surprise:that's for sure.

 

[shawn kloker]

Might be time to have a look at your steering head and swing arm bearings.

A well set up bike is good up to 120+ mph before wobble, but there is of course many factors that can create a wobble at different speeds, crosswinds, bumps or wallows in corners, sitting geometry, etc....

I had it happen twice on a vmax - once at 120mph on a wide sweeper corner with a wallow in it and the other time was on rapid decelaration at 120 or so mph - both times I managed to get out of it safely, but scary shit :surprise:that's for sure.

I'll bet that high speed sweeper was the frame flexing.

 

[maxcruiser]

I'll bet that high speed sweeper was the frame flexing.

Shawn, I believe you are right, it was before I put solid motor mounts and steel hollow dowel pins on the removable lower right frame section's bolt holes.

Mike

 

[MSGU1-4936]

not sure if its the frame flexing Shawn, I have a set of frame braces from RMS, and the reinforced swingarm from cycle one, as well I replaced the swing arm bearings less than 6 months ago, and the bearings in the steering head were checked and greased les than 3 months ago.

Ron

 

[Buster Hymen]

How's the air pressure in your tires?

 

[shawn kloker]

not sure if its the frame flexing Shawn, I have a set of frame braces from RMS, and the reinforced swingarm from cycle one, as well I replaced the swing arm bearings less than 6 months ago, and the bearings in the steering head were checked and greased les than 3 months ago.

Ron

I have all the crap on my bike and can still flex the frame.It is no where as bad as it used to be but is still there when you are really riding hard in the turns.

 

[MSGU1-4936]

Air pressure is good, weights are still on both wheels, I also have the beefed up fork brace. I did tighten the bolts on the fork brace, and on the handle bar clamps. Possibly just the strong gusts of cross winds. I was not in a turn this was a straight open section of highway. I will put the center stand on this weekend and see if the front and rear are snug.

Ron

 

[shawn kloker]

Air pressure is good, weights are still on both wheels, I also have the beefed up fork brace. I did tighten the bolts on the fork brace, and on the handle bar clamps. Possibly just the strong gusts of cross winds. I was not in a turn this was a straight open section of highway. I will put the center stand on this weekend and see if the front and rear are snug.

Ron

Check the bolts on the 2 removable frame pieces to see if they are tight.The one behind the radiator and the one one the right side that comes out to remove the motor.

 

[MSGU1-4936]

Just wondering Shawn if a wind screen would have anything to do with the wobble. I recently installed a larger wind screen, and this is the first time out on the highway with it.

Ron

 

[maxcruiser]

Just wondering Shawn if a wind screen would have anything to do with the wobble. I recently installed a larger wind screen, and this is the first time out on the highway with it.

Ron

I have both a small (Givi) and large (Memphis Shade Hellcat) windshields and there is difference in handling at high speeds. The large windshield creates more "lift/push" at high speeds which makes the front end feel light and can lead to wobble.

Mike

 

[MSGU1-4936]

Thanks Mike, I gues the only way to find out is to go for a ride with it off.

Ron

 

[gleno]

Thanks Mike, I gues the only way to find out is to go for a ride with it off.

Ron

Hi Ron,

I read your post yesterday and spent half the night reading about front end wobble.

This link deals with BMW handling issues but I think you will find it useful. http://w6rec.com/duane/bmw/wobbles.htm

and this is good too. http://w6rec.com/duane/bmw/forktool/index.htm

If you really want to do your head in go to google books and type in 'motorcycle fork wobble' :ummm:

Your fairing probably is having an effect.

 

[MSGU1-4936]

Thanks for info Gleno, I was reading the info you provided, very detailed and useful. It seems that in the cases mentioned the wobble seems to be limited to the handlebars, I experienced the whole bike going side to side, or at least thats how it felt. At no time did my hands leave the handlebars from the wobble.

 

[shawn kloker]

Just wondering Shawn if a wind screen would have anything to do with the wobble. I recently installed a larger wind screen, and this is the first time out on the highway with it.

Ron

I had a memphis shades Hellcat too. I was sick of getting stung by bees in the fall.It made it real squirly at high speed or in any kind of wind.I took mine off after only a few rides then sold it on ebay.

Take yours off and try it.

 

[broook]

I took mine off for a while last year as I thought the same thing but unfortunatly it didn`t make any difference.
Progressive shocks made a slight change in cornering and a big change on bumpy roads.
I have a set of Kawi ZX shocks on the way to try next spring. If they make a difference I will post.

 

[Robbarrie]

If you have taken a riding coarse they want you to learn how to do a push steer to move the bike right or left to swerve out of the way of a bad pot hole or something on the road. If you push on the right bar - it causes the bike's weight to shift to the right, much faster than trying to lean it over that way. That being said, allow you to lean the bike faster as you correct the bars to straight and lean in that direction to quickly swerve around something. It doesn't take much pressure on the bars to make the bike's weight shift in the direction of the pressure. Now in relation to a speed wobble : Your reaction is to compensate too fast and hard and next thing your going too far and hard in the opposite direction. This alone can be enough to put you down. Now do that at high speed it will be mutiplied by 5 or 10. The biggest thing I think is to stay calm and let the bike work itself out naturally. Light hands don't fight it. Some have said let go of the bars. I don't think I'd wanna try that nor suggest it, I'd sooner just hold loose and pray that I don't go down - if you got time !

I 'm in no way saying this causes one to get into a speed wobble in the first place I'm just going by my experience on what I did - that probably saved my life. Either give it some throttle or let it down ez but never hit the brakes. This will cause you to loose it ! You don't want to hit the brakes with the front end turned even slightly at that speed, nor want the back end try to pass you in the direction of the weight shift, left or right of perfect center. It's something that you just have to be aware of when you going that fast.

Best thing is to all this is prevention, don't ride that fast in the first place. But then again that's not much fun is it ! For most of us who this has happened to will tell ya how they saved it. But for those who never have, this is my advice. I'm alive now to tell you about, I hope you will be too to tell yours.

 

[lankeeyankee]

I have never experienced a high speed wobble until this weekend. I was out on the bike on a stretch of highway when I opened her up and off I went at one point the bike started to wobble, scared the shit out of me. I have never experienced this before, I rode most of the day cruising between 70-85mph. There was a lot of high cross winds this weekend and even at 70-85mph I would have to counter steer to get back on track. At what speed should I be experiencing this high speed wobble. Not sure if the wind was a big factor or there is a problem with the bike, like I said I have never experinced this before and I have opened her up on this same stretch of highway without any wobble.

:ummm:

I have had a few before I strapped my front end down The worst was at 125 wobbled back and forth 4 times shifting into 5th talk about shitting your pants. The onlything you can do is whack the throttle and try to get the weight off the front
I havent had any since I strapped the front down I am stable now all the way to 155+ on the speedo yeah its rough if you hit a bump and coming down from wheelies but its a whole lot better than wobbles

 

[Rusty McNeil]

I have had a few before I strapped my front end down The worst was at 125 wobbled back and forth 4 times shifting into 5th talk about shitting your pants. The onlything you can do is whack the throttle and try to get the weight off the front
I havent had any since I strapped the front down I am stable now all the way to 155+ on the speedo yeah its rough if you hit a bump and coming down from wheelies but its a whole lot better than wobbles

You keep your front end strapped for street riding?:ummm:

Rusty

 

[lankeeyankee]

You keep your front end strapped for street riding?:ummm:

Rusty

Rusty

Yeah ever since I strapped my front end down 3 yrs ago I have never had any wobbles. As I said the ride is rough if you hit a pothole and you have to be slow on speed bumps and going up small 1 in curbs such as turning off the rd into a store
The roads are pretty good here in TN. If I lived in PA NJ NY there would be NO WAY i could ride with a strapped down front end. I dont use it for a cruiser mostly street racing, bike nights and sometimes a Sunday Rip.
And the plus side I dont have to worry about emulators rebuilding fork seals or checking the fork pressure LOL!

No more wobbles for me :banana: