Topic: weebles wobble

[Sticky Gerbil]

But just sometimes while decelerating.

1980 CB650. The handlebars wobble sometimes when my hands are off the handlebars. It seems to happen more when decelerating. I took the front tire off and brought it to a bike shop; they said it was perfectly balanced. I had em put a new tire on it because it had a ching chang chong tire on it and the guy said the company wasn't allowed to make street tires anymore.

It doesn't do it as reliably anymore; is this normal? What should I do? 

[Sticky Gerbil]

Disclaimer: I am a European car mechanic.

That being said, at the risk of sounding like a moron, how do I check the steering bearings? How do I check the fork oil?

Tire pressure is perfect. What is the proper torque for the front axle (I am assuming you mean the two nuts on each fork end)? I used the German torque spec, "gutentight".

[Deltarider]

The handlebars wobble sometimes when my hands are off the handlebars.

At some speed it is normal. At any speed it is not.

[Stev-o]

Cal has given you some good advice, but I would go one step further: upgrade your stem ball bearings to tapered roller bearings.

Do you have a front fender?

[juliorice]

I agree with everything that has been said.  I chased a wobble problem exactly as you describe.  Fine on acceleration, would show up on decel.  Turned out to be loose spokes on the rear wheel.  Just something else to check.  Good luck.  Julio

[BobbyR]

But just sometimes while decelerating.

1980 CB650. The handlebars wobble sometimes when my hands are off the handlebars. It seems to happen more when decelerating. I took the front tire off and brought it to a bike shop; they said it was perfectly balanced. I had em put a new tire on it because it had a ching chang chong tire on it and the guy said the company wasn't allowed to make street tires anymore.

It doesn't do it as reliably anymore; is this normal? What should I do?

Please do check everthing mentioned here.  If you are using the tire pressures on the Honda sticker you can get a deceleration wobble. Modern tires are built differently today and require more pressure. Go up 10 lbs if you are at the sticker pressure and then lower it till the bike feels good to you. 

[jamesbekman]

What does "European car mechanic" mean exactly? 

[Deltarider]

Turned out to be loose spokes on the rear wheel.  Just something else to check.

Actually most 'unrest' at the front originates from the rear.

[Sticky Gerbil]

James: European car mechanic means I don't know that much about things that are not European cars, that is, until I completely disassemble them.

Cal: great response. I know nothing about the bike. I bought it from a cl trader. Thanks for all the suggestions I will try them all. Front tire is like 4 days old, the rear one is a coupla months old. Front tire is a Dunlop. Forks as far as I can tell are stock length. Bike is a daily driver now; doubt it was before. My model had an arrow --> for forward on the lower fork cap. It is correctly oriented. I will drain the oil in the forks and flush them if possible.

Stev-o: I have a front fender.

Julio: I assume you are talking about zillion spoke wheels. Mine are the black and silver star looking ones. Also, it only does it at times on decel, not reliably.

Bobby: I have no stickers as my bike is ghetto fabulous. I keep the tires at 40psi.

[750K]

Don't overlook your swing arm bushing as well, if the bushing is worn or the swing arm bolt is loose it can result in a wobble at times. My wife's cb400t hab a wobble going into a left hand turn, PO didnt torque the swingarm bolt to spec. That solved the issue.

[PeWe]

Bad/not tightened bearings in front can also be identified by braking hard with handbrake. But just a short brake, multiple times after each other. You will feel eventual play between fork and frame.  Possible when rolling the bike slowly without engine running.

One more thing is steering damper.
I mounted one for many years ago so I might have forgotten this kind of wobble.
I think I have this  wobble  when I had forgotten to set the damper to harder setting which is the normal.

Or when the wight balance is displaced to the rear.

[Sticky Gerbil]

So I took the bike out for a ride today on the interstate, which sucks. Tested for a wobble at all speeds and such, seems to only be reproducable at a medium engine decel around 40 ish. What the hell.

[BobbyR]

So I took the bike out for a ride today on the interstate, which sucks. Tested for a wobble at all speeds and such, seems to only be reproducable at a medium engine decel around 40 ish. What the hell.

If you do a search the wobbles come in on deceleration at around 40 or so. In my case it was low air pressure but you covered that.
You can take a spanner wrench and tighten down the steering head bearing. It can be a band aid or a diagnostic.  On the center stand the steering head bearing will want to center forks, due to a flat spot that develops over time. Steering head bearings only rotate a few degrees so they get a flat rather than wear out.   

[Retro Rocket]

If you're a mechanic then you will know how to tighten wheel bearings, do the same to the steering head bearings, check wheel for straightness, check wheel bearings and all mounts, make sure the forks are clamped tight, check swingarm bushes and rear wheel bearings and also the condition of the rear wheel and shocks, all can contribute to a wobble...

[Sticky Gerbil]

Gonna check rear bushings and steering head tonight. Rear wheel is fine . Rear shocks are 3 months old and set at a medium setting. No ply in rear wheel bearings. Will post results.

[Sticky Gerbil]

So I tightened the steering head, and the problem seemed to be the sameish. Checked the swing arm bushings- the swing arm slides back and forth, which I am assuming means the bushings are trash. Where to get them?

[Retro Rocket]

So I tightened the steering head, and the problem seemed to be the sameish. Checked the swing arm bushings- the swing arm slides back and forth, which I am assuming means the bushings are trash. Where to get them?

That could be your problem right there, do a forum search for Hondaman, {Mark Paris} he sells the best oilite brass bushes, he will also rebuild your swingarm completely if that what you want...

[ofreen]

 The handlebars wobble sometimes when my hands are off the handlebars.  What should I do?

Here is part of the answer -

https://www.youtube.com/watch?v=zCh7z5EwYF8

 

[Sticky Gerbil]

No.

[ofreen]

Deceleration wobble beginning between 50-40 mph is very, very common.  It can happen with any style of bike. Even a bike with everything in correct adjustment and appropriate tire pressure may do it, especially as a front tire wears.  You need to fix those swingarm bearings, but even after you do, you may have the wobble.  Every bike I've had from dirt bikes, dual sports, sport bikes and standard bikes have all done it to some extent.  Ask a Gold Wing owner of any vintage (bike, not rider) about deceleration wobble.

The advice the Hee Haw doc gave is valid.  If it wobbles when you take your hands off the bars, then don't do that. 

[Stev-o]

 The handlebars wobble sometimes when my hands are off the handlebars.  What should I do?

Here is part of the answer -

https://www.youtube.com/watch?v=zCh7z5EwYF8

 

Good one Greg!

[Sticky Gerbil]

That doesn't make sense. That's like me saying to you, oh, sorry, your car is old so there's nothing I can do to help you with an oil leak. Or hey buddy, sorry about that suspension noise just turn the radio up cause I suck at my job.

Clearly there is a problem here if the bike didn't exhibit this issue before. Accepting a dangerous condition is stupid advice. I will continue my diagnostic and repair until the #$%*ing wobble is gone, not just turn my mental stereo up.

[Retro Rocket]

Deceleration wobble beginning between 50-40 mph is very, very common.  It can happen with any style of bike.

I disagree completely, although it was common trait in older style bikes it is NOT a common thing these days, tire tech is a hell of a lot better, brass bushes, tapered steering head bearings and steering dampers and better shocks all help, if your bike is set up well it should NOT wobble at any speed, period.... There is a video here somewhere showing these wobbling 70's bikes, all were know to have inherent problems built in, not enough trail, wrong rake and trail combinations, poor suspensions, cheap bearings all of which can be sorted with the correct parts and maintenance....

[Stev-o]

Deceleration wobble beginning between 50-40 mph is very, very common.  It can happen with any style of bike.

I disagree completely, although it was common trait in older style bikes it is NOT a common thing these days, tire tech is a hell of a lot better, brass bushes, tapered steering head bearings and steering dampers and better shocks all help, if your bike is set up well it should NOT wobble at any speed, period.... There is a video here somewhere showing these wobbling 70's bikes, all were know to have inherent problems built in, not enough trail, wrong rake and trail combinations, poor suspensions, cheap bearings all of which can be sorted with the correct parts and maintenance....

And the video has a guy wearing a scuba diving weight belt to stop the wobbles!

[ofreen]

Deceleration wobble beginning between 50-40 mph is very, very common.  It can happen with any style of bike.

I disagree completely, although it was common trait in older style bikes it is NOT a common thing these days, tire tech is a hell of a lot better, brass bushes, tapered steering head bearings and steering dampers and better shocks all help, if your bike is set up well it should NOT wobble at any speed, period.... There is a video here somewhere showing these wobbling 70's bikes, all were know to have inherent problems built in, not enough trail, wrong rake and trail combinations, poor suspensions, cheap bearings all of which can be sorted with the correct parts and maintenance....

Modern bikes will do it.