Unstable front end part 3 - brown chamois moments

[Ray]

OK, we've discussed the causes and cures of speed wobble to the outer reaches of phyics. How about your most frightening occurances of speed wobble?

I've been lucky enough to only experience real good speed wobble a handful of times in the 10 years or so I've been riding, most of them not too serious. I attribute most to operator error, the most extreme occurance of which was...

I'd just done a crazy steep 1.5 mile climb on a dirt road in the Poconos. I was wasted. It was an early November ride (just last year), which can go either way in terms of weather and this day went the wrong way - the coldest and windiest day we'd had so far that season, by a good margin. I was descending down the other side of the mountain on a road that was nominally paved, but it was very narrow and very poorly maintained. It was also very steep, similar to the side we'd just climbed - generally between 14-18%. So I'm tired, I'm cold, the road is bad, the wind is blowing like crazy, and I'm going waaay too fast. I was modulating my speed with the brakes, but it was tough to stay below the mid-40s for most of the descent and that's about where I was when the speed wobble started on a slight curve. Given the combination of factors, relaxing just wasn't an option at that moment. Just when the bike started really bucking and my grip was involuntarily tightening, making the problem worse (I understood this fully at the time, but I couldn't seem to loosen my grip), a big-a$$ pickup comes screaming up the road trying to keep some momentum on the poor surface. And I'm drifting over into his lane. I was unable to steer the bike I was so busy trying to keep it from bucking itself right off the mountain. I realized I was cooked if I didn't get the wobble under control NOW. So, I did what I should have done earlier, and clamped the top tube with my knees. As usual, it worked brilliantly and I was able to get the bike under control and get back in my lane with a few seconds to spare. My guts weren't the same the rest of the day. Surely the most frightening moment I've had on a bike.

I'm pretty sure, based on this experience, that if I'd somehow found myself in Andy Hampsten's place on the Gavia in 1988, I would NOT have won that Giro.

Others?

-Ray

[Too Tall]

Descending the Blue Ridge Parkway from Jewel Hollow to Panorama in 1970. you could say I was riding a Columbus Bottecchia with 40 lbs. of panniers and crap but that would be an overstatement. Thought I was gonna die. Just stood on the pedals and caught air while lightly applying brakes. The road mellowed out and I survived.

No helmets
Tubulars
NR brakes
Priceless

[Birddog]

Heading S down Bobcat Pass in NM, just got up to about 35 mph hit something like a pebble and she started to go. It quickly became violent, I thought the damn bike was posessed and I was about to start the pea soup thing. I was all over my lane and at least one car went by with faces in the window clearly looking at me wondering ***. It was a 2.5 mile descent and the bike shimmied for about half of that distance. I'd get it under control, get back up to speed and then it would go again. To combat the shimmy, I did the logical thing, I squeeezed that handlebar even tighter, about as tight as my sphincter to be exact. After that bout, I did a little research and found out about the knee on the top tube. Later on I found out that my "death grip" was likely at least part of the cause. I did repace the stock "Unicrown" fork and that helped a bunch too. I was scared to death, and fully exhausted when I arrived at the bottom. Like Dave Kirk, says, all bikes have the inherent ability to shimmy, you just have to learn what causes it and how to neutralize it when it happens.

Birddog

[cpg]

I've never had it happen to me. I've owned and ridden lots of bikes. Not just ones I've built. What am I doing wrong?

Curt

[Bud_E]

When I was a pimply-faced 14 year old ( MANY years ago ), descending the road from the Griffith Park Observatory on my Schwinn Varsity I wanted to see how fast I could go. What began as a small wobble quickly became an wild adrenaline-fueled high speed oscillation across the road into the oncoming lane. I accepted the fact that I was going down hard ( of course in those days no helmet ) but I managed to gain control and come to a stop with no ill effects - luckily no cars were coming up the road or I would have been a hood ornament.

My confidence was shaken but what I figured out was that I was pitched forward and much of my weight was being supported by my hands which were on the handlebars. When I relaxed and leaned back some, the oscillation ceased. Hasn't happened to me in the 38 years since then.

[Ray]

I've never had it happen to me. I've owned and ridden lots of bikes. Not just ones I've built. What am I doing wrong?

Curt
You're way too relaxed on the bike. You need to tighten your grip on the worst roads at the highest speeds. That ought to do it. Hey, if a lot of this problem is caused by operator error - I know it has been in my case - the lack of it must have some relation to operator skill. So a tip of the hat to you. But its something everyone should experience at least once, so grab hold of those bars like you mean it!

-Ray

[sspielman]

You're way too relaxed on the bike. You need to tighten your grip on the worst roads at the highest speeds. That ought to do it. Hey, if a lot of this problem is caused by operator error - I know it has been in my case - the lack of it must have some relation to operator skill. So a tip of the hat to you. But its something everyone should experience at least once, so grab hold of those bars like you mean it!

-Ray


Like my friend Shawn says....."If you don't finish with pucker marks on your shorts, you aren't descending hard enough....."

[telenick]

'98 Triple Bypass ...Loveland Pass southside descent. Riding my trusty Giordana (rebadged Merckx) Excel tubeset, Sun tubular rims, 45 mph.

Wicked wobbled ...brought it to a stop ...cleaned shorts ...continued on to Eagle Vail for the completion of a great Triple Bypass (hottest one on record.)

After that I always descended with my knee on the TT to never have another wobble again.

[saab2000]

The only real brown chamois moment in my cycling life was about 10-12 years ago descending from the Bachtel towards Hinwil near my house in Switzerland.

The Cinelli XA stem broke. The only thing keeping the bars from just flopping by the cables was the bolt that tightned the stem from underneath. The stem snapped across the front. The bars were free to rotate and were very loose. But enough steering control remained for me to sort of brake and but one leg over the top tube and use one shoe scraping on the ground to get me slowed. I wasn't going overly fast, probably not more than 35 miles per hour, but that would have been enough to suck had I fallen.

I don't know how I didn't fall.

Anyway, I have never had a 'fear of God' speed wobble, but the stem breaking incident is probably equally bad.

[fstrthnu]

Campy Bora's. First generation all carbon tubular 2003. Just say NO! Very unbalanced.
Cascade Classic... though I was going to die. Was riding on a Colnago C-Something... no front end shimmy on that frame. Had plenty of weight on the front end too. I switched to Electrons for the rest of the season. Problem solved.

Fstrthnu

[gone]

Descending toward the Mississippi in Wisconsin on a long, 11% downhill and really letting it run, probably going well over 45 mph. Went around a gentle curve and hit a just smaller than fist sized rock that I didn't see in the shade just before the curve sharpened. Started wobbling like crazy so naturally I took a death grip on the bars which needless to say made it worse. After a second or two which seemed like a lifetime as I was heading straight into an oncoming car, I relaxed my grip on the bars completely (this was really hard to do at the time) and nudged the top tube with my knee. Wobble stopped, regained control and got back into my lane.

The first one I ever had was probably the scariest though 'cause I didn't know what it was and how to stop it. I was going down a long hill on a windy day and got hit with a cross wind which started the wobble. Thought I had a flat and quickly checked both wheels - ok. Scared like crazy, gripped the bars like mad, and hit the brakes (thereby loading the front end even more). Convinced I was going down, unclipped whilst still braking. Wobble didn't stop until I got under about 15 mph. That was a long time ago and I remember it like it was yesterday. Did some research on causes/prevention and how to stop them once they started.

As I posted elsewhere, my most recent one was post-accident when still not completely healed and riding like a coward. I know I was tense on the bike and gripping too tight. These three are the only ones I've had. They become much less fearsome when you know how to stop them.