High Speed Wobble

[Mopar_Tony_SF1]

I changed tires recently (from B'stone battleax to Continental tkv-11 / -12) and now have a high speed wobble on certain patches of the freeway. I've balanced the assembly. Only wobbles on groved concrete. Aspahlt and smooth concrete is ok. My H2 does the same thing on this strech of road. What is bothersome is my B'stones were perfect over this strech of road. Have any suggestions? Ditch the contis and try something else?

[Mike Barone #123]

I changed tires recently (from B'stone battleax to Continental tkv-11 / -12) and now have a high speed wobble on certain patches of the freeway. I've balanced the assembly. Only wobbles on groved concrete. Aspahlt and smooth concrete is ok. My H2 does the same thing on this strech of road. What is bothersome is my B'stones were perfect over this strech of road. Have any suggestions? Ditch the contis and try something else?

Hi Tony

When there are no other variables other than changing tires....ie....the mile before this everything was fine and the minute after the new tires were fitted the problem starts...it has to be something related to the tires or fitment in my view

Before taking the Continentals off ...check/try front and back tire pressures at 30lb. My experience has been that higher than normal tire pressures make the early model wobble more likely to happen.

Long shot here but check the tire diameters of the Bridgestones and Contis to see if they are nearly the same though if this was the issue it still would not explain the Conti tire behavior just over grooved concrete.

Some tires are just more prone to certain behavior like wobbling over grooved concrete or other unique things....it could be the Contintals are one of them.

Let us know how it all turns out


Mike

[alimey4u2]

If tires are OK, go down the usual route, check damper fluid levels in the fork tubes,fork bushings,wheel tracking, headstock bearings,swinging arm bushings, wheel bearings, rear shocks ( if twin shock,) wheel trueness & general fastener security etc.etc..... If you already know this, apologies..
As Mike said, some tires are more prone than others & is mostly due to tread pattern & or ply bias...

The "wobble" is it a slow weave or a tankslapper ?? Grooves... are they in the direction of progress or across the road ?

[steve murdoch icoa #5322]

My situation was the opposite. I had Metzelers, {ME33 and ME55 i think} on the '80 and i had no problems. When i switched to the Bridgestone BT45s the bike would "hunt?/wobble" over highway grooves and metal bridges.
Fortunately, neither road condition occurs often where i ride.
Evenly matched fork air pressure and oil levels made the situation better, something i tend to let slide.

[alimey4u2]

Evenly matched fork air pressure and oil levels made the situation better, something i tend to let slide.

I forgot about the balanced fork air pressure as I have a balance tube between mine on my 1980... I too run Metzelers & have found them to be the best for my style of riding....

[Mopar_Tony_SF1]

Thanks for the insight.

I will try knocking down the tire pressure to see what happens.

Bike was perfect until I changed tires. I am going to check balance again as well. Sure hope these tires are not prone to wobble as they were not cheap and I have 14 miles of grooved pavement on the road to work.

[Terry]

If you end up swapping tires you might want to try some good (and) inexpensive Kendas. So far on my 82 they work very well and no rain groove tracking like the Brickstones did.

[cbx6ss]

No tire expert here, but I wonder if rear wheel alignment could be a factor? Anyone have a tried and true procedure for ensuring the rear wheel is aligned with the front wheel?

[EMS]

What puzzles me is that it supposedly happens only on a certain surface. "Grooved concrete". The only reason I can think of is the tread pattern reacting adversely to this kind of surface. Unusual but not impossible, I guess.

[Jeff Bennetts]

What year CBX?

[alimey4u2]

No tire expert here, but I wonder if rear wheel alignment could be a factor? Anyone have a tried and true procedure for ensuring the rear wheel is aligned with the front wheel?

Only the taught fishing line method........

[Mopar_Tony_SF1]

Ok, now I'm bummed. Check balance again, etc., no change. Set pressure to 30 psi front & rear - a little better.

Last night I happened upon an old Metzler bulletin about the old laser tires, saying there was a tendency to produce wobble over grooved pavement and grated bridges due to the circumfrential grooves in the tires ... the new front Lasertech have these grooves removed... they also market their ME880s (nice tires, have on my V-max) as being supperior to other brands against wobble on grooved surfaces since the trires do not have grooves around the circumfrence. So what does my Conti front look like:



Perhaps this is part of the problem. What did my old B-stones look like that were excellent on all surfaces:



My pedestrian analysis says the grooves are giving me the problem.

[Mopar_Tony_SF1]

The "wobble" is it a slow weave or a tankslapper ?? Grooves... are they in the direction of progress or across the road ?

It is tankslpper wobble.

The problem grooves in the road are parallel to my movement. When chaning lanes (i.e. tires at an angle to rain grooves) the wobble goes away.

Hey George, when you rode my bike a few weeks ago (when we were getting on the freeway heading south) did you notice anything? This is one of the worst streches of road producting this wobble. We were not going that fast, however.

[cbxtacy]

seemed to have the typical CBX wobble, as long as both hands are on the bars, it's not to scary. I have no idea what causes it. I just replaced the tires on my 82, before it was great, now it wobbles. Your bike wasn't real bad. I had Kenda Challengers on it now dunlop 591 (my favorite) and metzeter marathon on the rear, a combination I've had no problem with before but this time it wobbles.

[Mopar_Tony_SF1]

Here is something funny ... I took my old ladys car in to get the oil changed and they said all the tires were about 15 psi overinflated. I said BS, and went home and checked the pressure and they were about 15 psi under inflated. Then I went and check my other cars and the tires were spot on. Mind you, I was using an nice Moroso racing dial type tire pressure gage ... but suspecting something was amis, I checked my wife's car with two sleazy pencil gauges ... here tires wer spot on ... and my other two cars were 15 psi too high.

So I checked my CBX again and both tires were WAY over inflated. Adjusted them down with the pencil gauge and viola, almost all the death wobble is gone when running over grooved pavement! Huge improvement.