Wobbles of Speed

I was out for a little training ride last Saturday when I experienced every cyclists worst nightmare at 45 mph.  No, I didn’t spontaneously combust due to my awesomeness.  Maybe that’s actually a dream….

I got the speed wobbles.  AKA – speed shimmy, death wobble etc.  In case you’ve never experienced this, let me summarize it for you.  Seconds are hours.  Don’t fear death, but do think about how bad road rash sucks (but picking scabs can be fun).  Hope for a field to lay it down in and not cliffs on both sides.  Hope a vehicle doesn’t run over you if you do crash in the road.  Here’s a [fat] kid who eats it (and a stupid friend who eats it as well – unrelated to the wobbles).

“Don’t put that on youtube!”  [Snickers…]

Back to seriousness.  Speed wobbles can be a serious thing – and if you’ve ever held on for dear life, you know.  So what causes the wobbles?  No consensus has ever been made.

The Bike
Many o’ things can be wrong with your bike.  Your wheels are not coplanar, you front fork is cracked, not enough trail, too much trail, frame isn’t stiff enough, frame is too small, headset is loose, hub bearings are loose etc.  So, check everything to make sure you are nice and tight.  Certainly, you’re stuck with the steed you have until you plop down cash for a “better” breed (but I’d start with new wheels), so if your headset isn’t loose or your hub cap things, perhaps it’s the combination between bike and rider (which is the more likely possibility).

The Rider
I believe this to be the bigger culprit.  If I was 5’2″ and weighed 115 bls I bet I could crush some descents (and ascents) and not have to worry about wobbles.  My center of mass would be lower to the ground.  Sadly, I’m a foot taller and more than 100 lbs heavier.

But this is only one reason why you can buy the same bike a pro was riding and you get the wobble.  Your descending style is important.  And the pros train for it.  Me, I learned to ride a bike down the street without eating asphalt 27 years ago.  And that was the last lesson I ever had in cycling technique (and from a guy who doesn’t have the best cycling style – sorry dad).

Unfortunately, to practice dealing with the wobbles one must induce the shimmy.  This isn’t something I am too keen on doing.  Ever again.  Especially at 45 mph.  But, there are some good practices we can all put into place to keep ourselves from having the wobbles.  And we can all mentally prepare ourselves on how to deal with it.  Opposed to the situation I was in this past weekend when I was praying for the best and cleaning out my shorts.

Preventative Measures

  1. Grant at Rivendell suggests never to ride a loaded bike a high speed with no hands.  Check.
  2. Ride the drops – this naturally brings the center of mass down and forward.
  3. Have a commanding, but loose grip.  It’s easier said than done, but when you get the shimmies, do not grip the handlebars with the death grip.  I did, and it instantaneously got worse.  You want to dampen the shims, not become part of the mass which is oscillating uncontrollably.
  4. Pedals at 6 and 12, outside foot down.  Change as needed.  This is a much easier position to hold than the 3 and 9 while keeping low.
  5. Unweight your saddle, but your butt doesn’t need to fully come off.
  6. Squeeze your knees against your top tube.  The theory is this helps to dampen the shakes.  And I partially agree.  This position also causes one to shift their weight forward, which I also believes helps.
  7. Pedal.

Of course, we can’t do all of these things at once.  But, when I descend I consciously get in the drops (which gives one a more powerful braking position), focus on a loose grip, bringing my rump off the saddle a bit and either pedaling or squeezing the knees.

What do when you get the shimmies

  1. Pray.
  2. Look for rougher road.  Not like the “wake up strips” or a pot hole, but maybe you come out of the worn tire track.
  3. Brake – the trick here is not to increase your grip.  Some practice braking without giving her the ol’ death grip is warranted.  I like the rear brake as you have less power (slower and more gradual decrease in speed) and it adds some weight to your front wheel.  Braking with the front can induce the shimmy or make it worse.
  4. Stay relaxed.  You know, it’s a beautiful day out and you’re in the mountains – nothing can ruin that!
  5. Move weight forward and lower.
  6. Squeeze knees.

Conclusion
Don’t freak.  Work on your technique and style descending.  As Grant says, be commander of your ship.  Have a plan and be prepared to deal with it.

One last video to show you what it looks like.

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2 responses to “Wobbles of Speed

  1. Pingback: DaVinci Maiden Voyage! | life on 2 wheels·

  2. Pingback: Rawhide Ramble 200k | life on 2 wheels·

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