“Best” meaning they have top end bike handling skills. Ever see the time Peter Sagan bunny hopped his bike over a rider that fell on the cobbles in Paris Roubaix? That = best.

So if you think Chloe Dygert doesn’t have “best in class” bike handling skills, then I’m not quite sure what to say. When you get into a resonance state, if she can’t get out of it, then pretty much the rest of the cycling population
couldn’t either. From the slo-mo I looked at, it’s pretty clear she was approaching resonance or certainly under damped. Most of the issue here was equipment, IMO.

It’s pretty clear what happened from the video. You can see it directly. She’s in a sweeping right hand curve, her front tire hits a pavement imperfection that starts an oscillation in the frame and pops her even more forward. She has to straighten out because of the oscillation and runs out of road when she hits the guard rail as the curve cuts her off.

Arguably, the frame should not have oscillated from a normal road imperfection yet that’s what happened. If she couldn’t get it back under control, I’m sure I couldn't have. She was waaaaay ahead on the clock at that time, I doubt she was past the edge of control for her on that bike.

It’s interesting that she’s switches bike sponsors. Maybe they couldn’t satisfy her that they’d found the problem. Then again, maybe it’s just a better financial deal. All I know, from an engineering perspective, if I were her I’d have to have a pretty compelling case made for me that they found the root cause before I’d get back on that frame design again in a race.

As you put it, yes. I am not disputing top bike handling skills. But it still stands that pro racers (and not just them) often put safety second to speed. Why would that descending style where you sit on the top tube (conveniently sloping to allow that use to great profit) be ruled as not allowed in pro racing (actually didn't follow that up, but there was talk to that effect it won't be allowed).

But tucking down on the top tube is unsafe for a different reason. But if you get the wobble effect in this position, then you are also screwed.

Her saddle clearly developped strong sideways oscillations, ergo she didn't have it squeezed between legs. I rest my case here.

I recall from two years ago in TDF (I think), one rider went down on flat straight road, for no apparent reason, like he was chopped down. Luckily he took nobody else with him. It looked like his front wheel got turned ninety degrees in a blink... I suppose ^&* happens on bikes engineered to or rather, perhaps, ridden to extremes.

Mind you, it doesn't follow that spending most of your life on a bike, like a pro racers do will somehow give you superior bike handling skills. Else why some would be touted as having poor(er) bike handling skills (usually descending) when compared to other pro racers and its not that they ride the bike any less than others they are compared to (gets noted frequently in race commentary). Many people have those skills like Sagan while not racing bikes at all. BTW I am his fan, in part also because he is almost my countryman.

Some pros look very uncomfortable while descending. Others have great skills. I agree all pros are not that great at bike handling, but most are going to be considerably better than average. There's probably just a lot more overlap between pros and non-pros when it comes to bike handling skills rather than fitness/power. Speed wobbles don't seem to be a major problem in the pro-peloton or out in the normal world for that matter. But I would imagine they are more likely to be an issue for a nervous stiff descender than someone with a more relaxed body, pro or not.

It's not a bike handling or skill issue.

I was not a pro, but started racing in the early 80's & was a solid Cat 2 into my 40's. Primarily Crits & some track, some results in the early mountain bike scene. I considered myself a very good bike handler and had a reputation as such among my peers. My hobby outside of cycling was sport bikes ( I'm currently bringing an older 900SS back to life). I was a very competent & fast rider. I was never stiff or nervous in any situation until I started to struggle with wobbles, it was a side effect of them not a cause.

I can say that even if you manage to fix the root cause, once it's in your head it is a tough thing to shake.

Incredibly true! I used to do a lot of sport biking and track days. One hard crash has you second-guessing and gets into your head for a long time. Oh, I love those old Ducs!! The 900 SS was fantastic.

I’m not disagreeing, but did you have more wobble problems once you started getting spooked by them?

Oh absolutely. Speed wobble lives rent free in my head, no doubt. The confidence went away very quickly and returns very slowly (if ever).

Did you contact Trek?

what did they say?

Did you contact Trek?

what did they say?

Did you contact Trek about this ?
What did they tell you?

Would love to know What does Trek say about the Domane and speed wobble?

Wow! Four posts in a row asking the exact same question about something that happened four years ago, and something that can occur on any bike.

I wonder if this high speed shimmy/wobble is caused by the forks on modern road bikes being too straight- not enough trail. Has anyone ever heard of this happening on road bikes from the 80s, i.e., when forks had far more trail?

I normally don’t respond to zombie threads being resurrected by a newbie, however, this case merits an exception. Are you seriously asking that speed wobble on a bicycle is a new phenomenon attributed to modern bicycle design! When in reality, modern bicycles are orders of magnitude more stable than bikes of the past.

Oh snap!

And are you seriously saying that it never occurred to you that exactly the opposite of what you're saying could be true?

Speed wobbles have been a thing since there’s been the safety bicycle. It was a common occurrence when I became active in the sport in the 70s and 80s, and it is a very rare occurrence today effectively it’s almost unheard of.

Long followup:

To answer the question "did I ever contact Trek?" The answer is no, because at the time I didn't think it was a Trek issue. Now, I am not so sure.

My Trek Domane has been relegated to indoor trainer rides only as the speed wobbles only increased and my fear only grew. Anything above 50 km would put me into a wobble, so I stayed below that speed. Though I got very good at controlling the wobble once it started. A skill I never knew I needed.

My best guess is that it has something to do with the front ISOspeed mechanism. If you go back to an earlier premise that was mentioned, which was a loose headset can be the cause of speed wobble you might find a connection between the headset and ISOspeed. The problem with this system is that it is difficult to know how much compression is needed when tightening the headset. Typically you tighten the headset and then grab the front brake and rock back and forth, if there is play you add more compression. With ISOspeed you can't do this because there is movement in the system and rocking back and forth tell you nothing. The other method is the wheel flop method but even this is flawed because the brake hoses add resistance. Finding the right amount of compression for the headset then becomes a guessing game. If you have never used or adjusted ISOspeed you will have a difficult time following along. I adjusted the headset until the cows came home and then some. I took apart the ISOspeed so many times to see if there was something that could be adjusted but I couldn't find it.

Trek doesn't use the front ISOspeed anymore and for me good riddance. This year I got so sick of the speed wobble every time I rode the bike, I finally gave up and purchased a Time ADHX. This bike has no wobble and I don't have to worry about losing control. I got my money out of the Trek frame and now as mentioned it sits on my Tacx Neo 2T. I always wanted a dedicated bike for the trainer so I am fine with it.

My theory could be right, and maybe wrong, at this point I really don't care. Even if Trek agreed that it was the frame, I would still use the replacement frame on my trainer, so I would be no further ahead. Bottom line, speed wobbles are scary.

Thanks for coming back and updating the thread.

What did Trek say about this?

See above

First, the "straightness" of the fork does not affect the trail; You can have two forks with the same geometry, i.e., position of the front axle with respect to the steering axis, but one with curved blades, and one with straight blades (angled forward from steering axis). Regarding stiffness between those two forks, the construction of the fork blades has equal or more effect than the straightness of the blades.

Second, you may have it backwards; Rewind to the early 1970s; General Motors wanted to have their second generation Chevy Monte Carlo have good tracking at freeway speeds, meaning, a positive centering force. They looked at Mercedes cars which had this, and had more caster angle (resulting in greater trail), so they imitated that and designed the Monte with the same caster angle. As my father would say, "A little knowledge is a dangerous thing." Yeah, Benzes had a lot of caster, but the wheels, tires, and steering linkages were all relatively light. The Monte had typically USA overdesigned-heavy on all of the above, to prevent warranty issues (only in recent decades has GM gotten away from that, instead, designing things light, test like heck until breakage, then beef up only where it broke, test again). So, the Monte pre-production samples go through testing... problems; That greater trail does provide greater steering centering, but the greater mass in the system makes it overshoot, greater with each oscillation ("positive feedback"), to the point that it goes out of control. In other words, SPEED WOBBLE. To fix this without a costly redesign, which would also delay vehicle introduction, they fit a "steering damper", basically a horizontally-mounted shock absorber with compression and rebound settings the same, to damp out (actually prevent) the oscillation.

So... increasing the trail, car or bike, will improve low speed stability and centering, meaning more likely to be able to ride the bike no-handed, and steering need less attention on long rides, versus twitchier, more agile handling, like for crit races. But at high speed, that increased trail and higher centering force at speed, can overshoot and cause oscillation.

Also, from what I have seen on this, I think the torsional stiffness of the frame, and lateral stiffness of the fork blades, may both be critical; My '89 Cannondale crit racer was the stiffest frame they ever made I think, never a hint of wobble as I maxed out the speedo at 65 kph. And relatively steep angles, 74 degree steering axis and short trail I think. IIRC, as they, and others started to go smaller and flatter and very thin wall on the top tube (less torsional and bending stiffness), for both lightness and perhaps smoother ride, I think some had speed wobble, until they reversed that trend a bit. I would hope that no new bike, especially a road racer, would go to production without testing for speed wobble.

EDIT: a bunch of good info on wiki, confirming what I said, plus other factors, especially under "two-wheel vehicles", but I recommend reading it all:

https://en.wikipedia.org/wiki/Speed_wobble

agreed