Low Speed Wobble?

Low Speed WobbleDiagram by Vittore Cossalter and Roberto Lot

I get this question frequently: “Do you know why if you let go of the handle bars under 30 mph my ‘Wing has a bad wobble?”

Early ‘Wings and most other bikes of this vintage don’t have any inherent wobble tendencies and they are rarely ridden at the “limit” where handling anomalies are magnified.

If a “normally” ridden early ‘Wing has a pronounced low speed “wobble” problem (less than about 45 mph…especially when slowing down) – that usually points to issues such as these:

1. Tire problems: incorrect size, incorrect tire pressure, tires improperly balanced, excess or irregular wear, damaged carcass, mounted with incorrect rotation orientation, etc. (front or rear)

2. Defective wheel bearings (front or rear)

3. Shock / spring problems (front or rear)

4. Steering stem bearings problems: worn, loose, pitted or with “memory” indentations

5. Lose / broken spokes / wheel issues (front or rear)

6. Defective swing arm bearings

7. Weight distribution problem

8. Overloaded vehicle

9. Too much weight carried too high on the bike: for example: heavily loaded top trunk or lugggage rack

10. Brake problems: loose, binding, warped or damaged components

11. Poorly installed, handlebar-mounted windshield

12. “Misbehavior” by poorly coached passenger

13. Steering damper improperly mounted or adjusted (if equipped)

14. Loose engine or other major drivetrain mounting bolts (thanks to John Relph in the UK for this one!)

15. Counterweight issues:

GL1100 Fairing

GL1100 Counterweight

‘”All GL1100 Interstate and Aspencade models came with a 3 pound counterweight that acts as an electrical junction box as well as a dampener to prevent deceleration wobble. If the mounting hardware for that 3 pound counterweight is loose, if the 3 pound counterweight is not mounted to the fork pipes properly, or if it is removed from its mounting at the fork pipes, a very severe uncontrollable deceleration wobble can be aggravated. This problem does not apply to the naked GL1100 Gold Wings, but if the Hondaline fairing is added to a naked GL1100 Gold Wing, the kit came with the 3 pound counterweight. If the owner fails to install the 3 pound counterweight with the Hondaline fairing, a very severe uncontrollable deceleration wobble can be aggravated.

Howard Halasz

GWRRA Wing World magazine contrubutor

If a “normally” ridden early ‘Wing has a pronounced high speed “wobble” problem (60mph+) – that usually points to issues which include all of the above plus these:

1. Aero imbalance: for example – fairing hung crooked

2. Problem with fork alignment

3. Problem with swing arm alignment

4. Problem with frame alignment including cracked or bent frame

Any single track steer vehicle (like a bicycle or motorcycle) will have some instability at some point in the operational speed range. The physics of “wobble” and “weave” are very complex. They are explained quite well here by Vittore Cossalter and Roberto Lot including neat videos!

Engineers take exceptional pains to eliminate or minimize these instabilities and still retain good overall handling characteristics. Many compromises are made to accomplish this.

But, engineers assume that you will keep at least one hand on the bars at all times, so they don’t concern themselves with “low speed, coast down wobbles with no hands.”

All motorcycles with conventional front suspensions do this to some degree. Usually, it’s nothing to worry about. Fixing problems on the list above will usually make the problem less noticeable.

Comments

  1. I have an 86 and an 83 that both have this wobble problem. Everything is tight and bearings are all good or have been replaced brakes and tires have also been replaced. It is almost as if it is some sort of phenomenon with the weight of this bike. I learned very quickly to keep your hands on the handlebars while decelerating

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