Handlebar Shimmy/Wobble (HELP)

[frusso10]

I can’t figure this out! I’ve been riding road bikes for about 10 years now and I seem to ride fairly steady. I’ve been told by people drafting me that I ride smooth and hold my line. But every once in a while and for no reason that I can see my handlebar will start to wobble which transfers throughout the bike. I have three road bikes and at certain times have done it with all of them. Seems to accrue while going done hill in a cross wind. I’m I tensing up? When I start to wobble do you know of any way to stop?

Thank you. Any advice will greatly be appreciated.

 

[FrankBattle]

I assume here the wobbles happen while you have both hands on the bar ..

.. I have experienced some wobbling while going down an incline free-hand. It's due to the size/geometry of my frame and I can stop or minimize the wobbling by clamping my thighs around the top tube. My guess is yours may not be a frame issue.

In your case, check a few things:

Headset (too loose, bearings loose or missing, bearing retainer bent ..). How old are the headsets?

Do you have quick release skewers? Are they on correctly (cone-shaped springs mounted with the smaller ends inward?)

Wheels all true .. really?

Try a new headset on the worst offender and see if the problem disappears.

Just some ideas. FWIW, I eventually had to replace the headset on the one frame I had that had the wobble .. it was time as I ride that guy hard and in rain etc.

 

[frusso10]

I assume here the wobbles happen while you have both hands on the bar ..

.. I have experienced some wobbling while going down an incline free-hand. It's due to the size/geometry of my frame and I can stop or minimize the wobbling by clamping my thighs around the top tube. My guess is yours may not be a frame issue.

In your case, check a few things:

Headset (too loose, bearings loose or missing, bearing retainer bent ..). How old are the headsets?

Do you have quick release skewers? Are they on correctly (cone-shaped springs mounted with the smaller ends inward?)
Wheels all true .. really?

Try a new headset on the worst offender and see if the problem disappears.

Just some ideas. FWIW, I eventually had to replace the headset on the one frame I had that had the wobble .. it was time as I ride that guy hard and in rain etc.

Thank you. I'll check. The bike I was riding is a new bike 800 miles. Both hands on the handlebars. I'll try clamping my knees to the top tube.

I have two other bikes and have had wobble with both. But only in certain conditions.
Thanks again

 

[JungleBiker]

I was reading just yesterday this article about shimmy and one of the causes could be incorrect fork alignment:
http://www.velonews.com/tech/report/articles/9786.0.html

 

[gclark8]

A couple of ideas, stem length? Longer than 100mm?

Wheel balance and tyre mounting, manufacturers mark at the valve, not opposite.

 

[frusso10]

A couple of ideas, stem length? Longer than 100mm?

Wheel balance and tyre mounting, manufacturers mark at the valve, not opposite.

After posting my shimmy problem message I washed my bike and noticed a slit in the front tire which crated a small bulge in the side wall. This could have contributed to my problem Thank you