"SPEED WOBBLES" - how common are they?

[DRM]

I used to get it descending on my Giant Defy Composite, at anything over 38 mph it would start, knees against the top tube calmed it down, but swapped the factory wheel set for an inexpensive Shimano R501 wheel set and it’s not happened since

 

[cougie uk]

Only had it once on one bike - a giant TCR. Descending a hill in the Peak District with a nasty side wind. Never had it again so I guess it was a particular combination.
Once in 40 years or so isn't bad I guess.

 

[DCBassman]

Clamping the top tube tube doesn't work when you've got this problem on a mixte...

 

[lazybloke]

scary when it happens .i had this descending Otley chevin but had read that putting your knee to the top tube would cure it which it did ...god bless shared information from others who were there before me

Ha, the Chevin was my first speed wobble; over 30 years ago. I've never forgotten that terror.

There are no hills like that where I live, but there's a short drop near me that I reckon is steep enough for a crack at 50mph. I bottled-out when the bike started to feel very unstable.

 

[mustang1]

I used to get speed wobbles occasionally on my old road bike from 20 years ago. Not frequently, but often enough for me to be aware (and it was a good learning experience).

With my newer, and far more expensive, road bike, i habe not had any speed wobbles.

 

[HLaB]

I've had it a few times on TT bikes sprinting for the line having probably not fully transferred my weight balance properly. The first time it happened it was a converted sportive bike with TT bars, it was compliant enough to let me sprint through it but the 2nd time I had one it was a full on TT bike and it seemed uncontrollable. It might have happened since but I couldn't say for certain as anything has actually been controllable quickly with clamping of the top tube and never escalated to a full on wobble.

 

[robjh]

Rare. Happened to me twice in 40 years riding, and the second one, at 42mph downhill with a following car, scared me so much that 10 years later I still instinctively touch the brakes when I get over about 35mph.
The first time was probably due to badly packed front paniers on a tourer, the second - no idea, I was on a light road bike with no obvious cause.

As others have said, there are tricks involving lifting weight off the saddle and knee-clamping the frame, but you learn about these afterwards and I've thankfully not had any cause yet to put them into practice.

 

[ColinJ]

Hang on - I'll find one of my old posts...

I chased the same rider down the descent of Holme Moss towards Woodhead on two occasions.

The first time, he was riding a heavy touring bike and the second time he was on his lovely new lightweight carbon fibre racing bike. He experienced violent shimmy on the right hand bend at the bottom of the descent on both occasions!

Since the weather conditions were different on the two days and the bikes were very different, I conclude that it was due to the way he was riding the bikes. I had no problems either time. I think he carried too much speed into the bend, scared himself, tensed up and got into panic braking. I knew what the descent is like and probably began braking before he did so I was able to do it in a much more controlled fashion.

I did look up what to do at the time, so (hopefully!) if it ever happens to me, the top-tube knee-clamping thing will stop it.

 

[presta]

I've done tens of thousands of miles on mine without any problem at all, including coming off Fleet Moss at 47mph. Then more recently I changed the stem to one about half the length....

I was riding down Market Hill in Maldon. It's only a shortie, but it just touches 1 in 6 at the steepest point, and has a bend which is fun to go round flat out with the bike heeled right over if the cars don't dawdle. That was where the shimmy hit, right on the bend at the steepest point.

 

[johnnyb47]

I strangely get speed wobbles as I pass the beer garden.They get that bad they often throw me off straight into the beer garden were I have to stop and have a pint to calm my nerves down.

 

[Paulus]

I've not had a speed wobble for a long time. The last being 50 years or so coming home from school. Coming down Osidge Lane, quite a steep hill, on my old Raleigh 3 speed. The knee on the crossbar did the trick, then a generous amount of front brake.