An hour record really isn't a great example of something that calls for stiffness. Aero is all. Of course, aero was somewhat of a fringe concept when Merckx did his ride.

As long as the chain stays on at first, it really doesn't matter how stiff/not stiff those bikes are. I always thought it was funny that Merckx' bike was lightened to an incredible degree for the time. Just not that important once it gets up on plane. Which is after the first 15 seconds.

Yeah, he might have some good ideas, but his "tests" and "studies" are so badly done that they are essentially useless.

400 watts? Record would have been reset many many times. By most anyone.

Widely reported at the time to be Reynolds. The lightweight set that had been around for already a long time then. Reported as everything since then. Pino Morroni told me what the frame was and I will believe him.

No one here seems to have the faintest idea what is involved in riding a bike on a track.

Boardman record was controversial to say to say the least. I honestly did not know about the other ride. And thanked the man who told me.

Pedal hard. Turn left.

Eddy Merckx wasn't anywhere in that remote ballpark. Even a really big guy on a fairly upright fit running beefy touring tires could smash Merckx's record if he could put out 800W for an hour.

It's hard to know Merckx's aerodynamic and tire drag with confidence, but my back-of-the-napkin guess for his power is similar to GhostRider62's.

It was at altitude. Some have estimated the power to have been 365 watts. In any case, your 750-800 watts is crazy wrong. It was not Reynolds tubing and the record has been broken a number of times. Name me a single rider who has ever had an FTP over 750 watts. 500 watts is extraordinarily rare, it takes a big man with huge VO2 max and high lactate threshold. More importantly......

Your example is completely not relevant anyway. During a steady state effort at high cadence as you can see from the video of attempt in Mexico, the actual force on the pedals is quite low. There is even some slow motion video of him.

Like Nascar.

Zactly.

This is why I prefer F1. F1 turns both ways, and has to use their brakes.

F1 uses rim brakes, right?

Actually, there was a NASCAR race on the other day with right turns. Totally threw me off at first.

A stiffer suspension is faster weight transfer, actually called load transfer since, like a go-kart, it's not very much due to body roll. And then faster load transfer is more traction on the turn-in. The problem is, how fast of a responding vehicle can the driver or rider handle ?

Also, faster load transfer works the tires harder and therefor the setup for a low-traction surface is a softer suspension.

The other subject was "Turn left". Well, turn-left is okay but steering is really a leveraging of the tire against the track. Then the contact-patch deflects out-of-line from the tire. As long as the contact-patch can further deflect then there is traction. The path of the vehicle is the result of the leveraging of the tires against the track but since both the front tires and the rear tires have contact-patch deflection then there is tire drift at both the front and rear such that there is not much apparent steering angle at the front wheels. The contact-patch deflection is called "slip angle" but really should be called drift-angle. Oh, on a four-wheel vehicle it's the outside tires with load on them that have significant slip-angle and drift in a curve. Note that the driver or rider doesn't steer through a curve under g-forces but just experiences the natural path of the vehicle due to the leveraging of tire force !

Now, for instance, the sport of "drifting" is really a sport of power-sliding because the rear tires are overloaded and can no longer further deflect the contact-patch. That's a slide.

Yes this is true, but not really the full story. A stiffer suspension will tend to increase dynamic tyre load variation when cornering, braking and accelerating, which in turn loses grip/traction (as tyre load vs grip is non-linear). It's complicated and optimum setup is pretty circuit dependent too. But the basic aim is to run as soft as you can get away with, rather than as stiff as you can, if that makes sense. This is coming from several decades experience of race engineering at the highest pro level (BTCC in the 90s and F1 from 2000-2010).

Well, as long as the tire can increase slip-angle under increasing load then that is a gain in traction even though it is also increasing drift. See, if the tire takes a larger load without sliding then that is more traction demonstrated. This fundamental relates to either increasing speed and g-force in a curve or to a re-balancing of front-to-rear load transfer.

Now very stiff tires can take very large loads and that's how it's done. But a stiffer suspension is not an increase in load-transfer but just faster load-transfer. And that's why an increase in load-transfer is more traction on the turn-in. The balance of the front-to-rear load-transfer can be changed and the speed of the load-transfer can be changed but not the total load-transfer. Well, I mean that the total peak load-transfer is not changed with suspension stiffness. It can be changed with vehicle height or with vehicle track-width.

To relate all this back to bicycles, it could be said that many bicycles, like go-karts, just use tires and frame or fork deflection for a suspension.

I wonder what chain lube they used to break the record?

Probably wet for less friction.

John

Okay ... the old "if you can't do it you can't understand it" fallacy. So a physicist and a physician who can measure every aspect of a barbell, and the weightlifter, can track with video and sensors the entire performance of the bar and the lifter, and can do all the math to fully understand how the lift was done, how fast the bar was moving at a given time, how much it flexed, how much the lifter's body changed shape under load ... not to mention heart rate, BP, respirat6ion, whatever else .... don't know crap because they cannot make the lift.

Right.

Secondly .... YES, as you chose to overlook most likely because you had no logical refutation and had already blown your illogical refutation above ... there is No Direct Correlation between frame stiffness and frame "performance" in those very different examples. You can choose not to see stuff, but it doesn't go away, sorry.

On top of all that ....

So basically you were completely wrong from the very start …. On just about every important point of your post.

Yeah, I think I won’t take your word as authoritative, eh?

Let’s move on.

I have no idea if this guy was actually a crew member, an engineer or even a fan of any motorsport .... but have no reason to doubt him. And if he really does have the experience he claims, I certainly wouldn't debate him ... on suspension set-up, at least.

Having hung around motorsports for a few years, and having listened and maybe learned ..... what he says makes sense ---- sure, the physics can be interpreted a bunch of ways, but what really works on different tracks is what matters.

But .... bicycles.

This is another thread where someone became an expert after reading an article on the internet--and read it almost all the way through---, and was kind enough to enlighten us with the latest "knowledge."

And, F1 drivers wax their chains.

All true in theory and good to see someone who at least understands the fundamental difference between dynamic load transfer and chassis roll. If track surfaces were all billiard smooth with no kerbs then you wouldn't need any suspension i.e. a go-kart sat a few mm off the ground would be the best solution. But unfortunately there are kerbs and many lumps and bumps on all race circuits I've ever been to. Some are much more bumpy than others obviously. So you have to compromise between the speed of response to a steering input and the tyre load variation when running over all the bumps and kerbs. A softer suspension reduces tyre load variation, which nearly always results in faster lap times and less tyre wear (providing it is very well damped). So why not go really soft then you ask? Well that causes potential issues with geometry (camber, toe etc) and then there's ride heights and of course aero performance to consider.

But to be honest this is all pretty irrelevant to bicycle frame flex. I only mentioned this to highlight the potential difference between someone's subjective perception of stiffness and objective performance. They don't always match up. Like in this race car example, a stiffer suspension might well feel like it has a sharper turn-in response, but you might not notice a loss of grip mid-corner or loss of traction on a bumpy exit (especially with TC). That's why we have data and engineers to analyse it to death!

Full disclosure: Sosenka was popped for PEDs at least twice, although not for his hour record ride. I suspect the UCI thought he was juiced for the hour record, too, but couldn't prove it. There's got to be a reason his record-setting ride is almost universally ignored in the bike racing community.

And Merckx was busted three times; once before he set the hour record and twice after.

Stock cars use brakes when they hafta. Unlike F1; they don't have abs, or power brakes.

ABS is not allowed in F1 regulations. That's why they often lock wheels under braking.

That's true.

I really like the aesthetics of old bikes, but modern CF road bikes are just awesome all around and great to ride.
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I know I'm going to regret this, but...

Regardless of how much or whether lateral energy is returned or wasted, how can the measured deflection possibly affect that?

Take rider A on bikes X and Y. Rider A always has an identical pedaling style, and puts 5w laterally into the BB. Bike X deflects 4mm at the BB under rider A's 5w lateral. Bike Y is stiffer and deflects 2mm at the BB under rider A's 5w lateral. Bike Y deflects less, but still absorbs 5w laterally. In other words, the less deflection of the stiffer bike doesn't mean there's less wasted effort deflecting the bike, just more resistance to the same wasted effort. It would be like saying that a stiffer car suspension makes the road smoother.

Now rider A may prefer the feel of bike Y, of course. Bike Y may be sharper-handling. I don't see how bike Y can be more efficient though.

This of course also means that "planing" (which is the damned stupidest word for the suppose concept) is bunk, because deflecting MORE also doesn't mean anything better either, inherently.

I'm not sure your last paragraph about planing follows--as you note, the stiffer frame is more resistant to the 5w. Doesn't this translate to less energy stored and returned?