Bacciagalupe

Sure, if you're Romain Bardet. In that case, K is at 15 seconds. Even given that K is a relatively simple model, that parameter change actually reinforces my position that the numbers the teams were thinking (10-20s gained) are not orders of magnitude different than what you'd likely hear 'round these parts.

I would comment on how bike changes worked out, but I'd rather not be accused of spoiling anything. I could've sworn there was a tag for that....

Doge

Calculations based on weight are fairly insignificant. Again, as both bikes are likely near the same mass.

The wheels are different with climbing wheels being near 50% of the TT wheels.

This goes to that conversation that mass is mass. Statically - yes, moving, certainly some don't think so (nor do I).

tdong

if the rules apply to everyone then why bother allow change bike ? if you can't climb that mean you are weak and let better rider wins.

Grasschopper

Uploader has not made video available in my country. WTF UCI?

San Pedro

I'm usually the one who gets that message. Bummer, but I bet there is something on YouTube.

Grasschopper

Eh...I've got it on my DVR at home...I watched the Elite Women's TT last night but was falling asleep toward the end so I went to bed. I'll watch the men tonight.

Athens80

The UCI broadcast is for countries who don't have an official broadcaster. Steephill has a list in progress for Live Video Streaming and TV Coverage. US online options include NBC Sports Gold and FuboTV.

Grasschopper

I've got the Olympic channel so I had it DVRed. Great race IMO.

Falchoon

I watched some of the highlights of this, especially interested in the bike change bits and thought the majority of the riders that did the bike change were clumsy and amateurish looking. And the helper pushed them off too hard almost causing some of them to crash. A lot of the riders were having trouble clipping in and wobbling around like Freds. Surely they would of practised doing bike changes? Didn't look like many of them had.

rpenmanparker 

Was the change being carried out already into the upslope. That could be a problem even for a pro.

Maelochs

The change area was on a very slight uphill ... but mostly form what I saw, it seemed the pressure got to people. Timing things properly takes practice, and apparently no one had.

More than pushing too hard, it seemed a lot of mechanics didn't get to push the rider before the end of the transitions zone, so the rider had to clip in and pedal off, uphill, from a dead stop, which cost more time than any bike change could have saved.

The fastest I saw was ten seconds ... but I'd still call it fifteen counting braking and acceleration to competitive speed. The worst were painful ... a Lot of riders on a three-or-five-percent slope trying to clip in and take off without assistance.

RChung

Maelochs

Excellent graph ... as in, simple enough that I can understand it (I think.) Looks like four guys pulled off a bike swap:y Roglic, Oliveira, Keldermann, and Gougeard. (Didn't Gougeard crash?) Thing is it is impossible to tell how well the others would have climbed on their TT bikes.Looks like six of the top ten didn't switch.

Now we need a graph showing the time it took each one to swap bikes.

Garfield Cat

How about the Engineering Notes by Cervelo?

https://www.cervelo.com/en/engineeri...weight-vs-aero

Maelochs

"But where is the tipping point? How steep does a climb have to be before the weight savings trump the aero gains? The answer depends on the rider’s weight and speed, as a faster rider would encounter higher aerodynamic forces while the gravitational forces stay the same. For an average 250 Watt rider, the tipping point is around a 5-per-cent slope. For a good pro who puts out 400 Watts, it’s 8 per cent."

So for me ... basically forget aero ... a .001 % slope and I am tipping over.

Grasschopper

Right it would bve really interesting to see how each guy would have done under the same circumstances. I'm sure that this was Tony Martin's argument against this course and against the allowance of bike type swaps for the final climb. There's so many factors for this one:

How well was the swap executed? I saw a couple completely botched swaps, bad clip-in jobs. But then there were a couple toward the end around 7-8 seconds at the end count. But again to Froome's comments before the race: how much momentum was lost? What about rhythm?
How comfortable is each particular rider on the TT bike? That climb was pretty nuts....all those tight switchbacks at the bottom. If a rider isn't comfortable on the TT bike then making those turns on one would be very hard and would mean slowing down even more than normal...regardless of the gradient.

So the question is WAY bigger than just aero vs weight. The guys that put time into perfecting their TT riding are going to be more comfortable on the TT bike than a rider that just TTs because they have to. IMO the bike swap was costing people a minimum of 10 seconds...and the question was could they make that up on the climb. And making that time up was not just aero vs weight...handling (cornering) and pure acceleration had a lot to do with it too.

Honestly when I first heard about it I thought it was a bad course because it hurt the pure TT guys...but having watched it I must say it was hugely entertaining and in the end that's what this is all about. The Tony Martin's can be pissed that the course was a disadvantage for them...but last year a pan flat course was the exact opposite, it favored the pure TT guys. They aren't going to have a course like this every year and personally I think it was ok to have as a one off odd ball course.

wphamilton

Makes you wonder, how many seconds could they potentially save if they perfected a bike swap at speed. Cowboy dismount/mount (spinning) while moving, or swing a leg over the top tube, clip in cross-legged and mount up.

San Pedro

Jump off the top tube of a moving bike to another bike. I'm sure it would make it into all kinds of action movies... if there weren't cars.

Maelochs

I'd bet Zdeněk Štybar could have done it in five seconds.

I bet all of them could have done it in ten and gotten good launches if they had bothered to practice.

Not sure about standing on the saddle one-legged and hopping onto the saddle of the second bike, which the mechanic is pushing uphill .... Peter Sagan could do that, maybe no one else.

Colnago Mixte

Looking at the thread title, I thought this was a political post about Donald Trump's weight. Glad it wasn't. Carry on . . .

joejack951

It's quite possible that on fresh legs and with an uncluttered mind that all of those stumbling pros performed a super clean bike exchange on flat ground. Now pump out hundreds of watts for however many minutes straight in the world TT championship starting on a decent uphill grade and that same bike exchange is a little more difficult.

RChung

Five seconds is slow. .

fietsbob

IHPVA Battle Mountain Nevada , have been timing flying 200M speeds of over 80 MPH , for 16 years , now..
current record 89.59 MPH/ 144.17 kM ph .. 200 Meters, covered in 5 seconds (4.994")

UCI Bikes are an appendage under a big ball of turbulence trying to push itself thru the air.



...

RChung

That's a downhill course. They don't take an average of speeds in both directions.

Racing Dan

The climb is about 300m. Assuming a weight penalty of 2kg that is a 2*9.82*300=5892J penalty. At 400w the it takes 5892/400=14.73s to deliver that energy, meaning the time penalty for riding the heavier bike is 14.73 seconds.