So short sighted. How fun would a weekend of elite men and women going after the record be? Pick numbers out of a hat to determine order and battle it out!

For those who don't know...Aquascalientes is fast but not just because it's at a perfect altitude, which it is. It's also the average temperature, air density, and fast (but cheap) track surface that all combine to make it faster than any other track in the world.

The town has also embraced athletes coming there for attempts and do a great job hosting them. It's actually a really nice experience.

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Jim Manton / ERO Sports

There will be live video via the UCI with english commentary. One week from today. Time TBD. https://www.facebook.com/Tofthour/

BTW Jim, I do really like your idea! It would be exciting to see a bunch of riders duke it out. I could even see it being a yearly event. The "Hour World Championships" or something.

IIRC, Thomas Dekker didn't go at the "ideal" time: I think he went too early in the day because of broadcast commitments back to Europe.

I think Molly went the same day (?) as Dekker -- if not the same day, it was maybe a day later when the UCI commissionaires were still on site. She went at a better time of day.

Whenever I hear talk about the best time of day, or best day, it's always in regard to air density. At higher temperatures air is less dense. Also you can hope for a barometric pressure on the low side. At or near sea level it makes sense. But if you are already at > 6k ft, you are at the part of the curve where further decreases in air density have little positive effect on speed. Particularly if you are not fully acclimated. I never see it mentioned that power will also be lower if the air density is lower. Surely they aren't forgetting that...? Plus there is the factor of heat having a negative impact on performance. A temperature in the 80s with significant humidity is hot enough to reduce my output in a 1 hr race. I'd prefer if it was <70.

The other factor would be rolling resistance of tires, which would favor higher temperatures. That one isn't going to be a lot on the track, but ... something. Still, I'd want to stay away from temperatures that are high enough that it might impact my performance.

Air density is certainly one of the factors, but when I looked at the problem I was looking at a lot more than just that.

Are the factors you considered secret info...?...;)

A few minutes with google indicates that the O2% doesn't change significantly with temperature, so there is no esoteric bonus there. Humidity will decrease the density of air, but the introduction of H2O vapor will reduce the amount of other air molecules per volume, reducing O2%. So wouldn't high humidity result in an even bigger hit on power output than the change in density would indicate? Why does everyone want higher humidity? It's easier to breathe air that isn't *real* dry but AC isn't dry this time of year.

I'm sure I'm not unique, and I'm also sure that some other teams considered stuff that I didn't even think about -- but I was sorta surprised about what Dekker's team didn't consider.

All happy record attempts are alike; each unhappy record attempt is unhappy in its own way.

I'd like to hear your thoughts too :)

There's lot of stuff to consider with an attempt like this - temperature, air density, O2 availability, track surface and geometry, circadian rhythm, logistics, time available for acclimatization, TV coverage. And probably others I forgot and/or haven't thought about.

This was the best date I could find for this year and I really wanted to get a shot in this year. Summer (in Europe) makes acclimatization a good bit easier as I can go to altitude much closer to home (the Alps) without snow. And it's easier to get time off from work as it's standard procedure to take several weeks off during July in Denmark. Next possibility would have had to be after the racing season ends, so that would have to be around November 1st the earliest - but that would complicate the vacation from work and acclimatization part.

That they have just sanded down the track is definitely not optimal as there's a lot of dust now that seems to slow the track down quite a bit. I hope that can be fixed to some degree the next days.

Oh, and thanks for making this thread, Ron :)

Hey Martin do you listen to Cyclig Time Trial podcast? I think one of the recent ones had a team that went south to Mexico and they had a similar issue with track resurfacing, might give you some insight! Good luck :)

No - was that with Rob Van Houweling? Because he's helping me already :)

Thanks :)

Thanks for the updates.....great to see a guy who has to worry about time off work, where to go close to home for altitude training give this a go. It's almost like your attempt is this stealth Graeme Obree style gig where a regular guy is taking on the protour marquis athletes and no one cares that he's messing around with washing machine bearings until he blows past Rominger and Indurain! Go Martin....take out Wiggins for the working man!

Yes! Great to hear he’s helping, he sounds extremely knowledgeable. Looking forward to this event.

I hope everything goes to plan.

Good luck!

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Developing aero, fit and other fun stuff at Red is Faster

No need -- I gave Rob all the calculations I had done for all the variables we'd thought about. The track had been sanded just before Molly's attempt and I was worried both about dust in the air and also whether it would screw up the Crr estimates that we'd done for the track before the sanding. I had historical records for baro pressure and temp for the dates of the attempt for previous years, plus hourly temp and humidity and rho readings that Rob had collected that week, so I had a reasonable idea how rho and temp would change over the day. What we didn't know was exactly how Molly would respond to the temp. Rob and Molly made the final call about that.

Best of luck!

Glad to hear you made it there! Hope they have a plan for cleaning it up before your run. And don't forget to kick some butt Thurs! Is it Thurs for sure or do you have a couple days window?

Man, that is a lot of dust....
https://www.facebook.com/Tofthour/

It's Thursday for sure. One go. Let's hope it sticks!

It was already a little better today with the dust. 10+W faster today. But they will start the big cleaning tomorrow. It still seems to be ~10W high in Crr compared to what it should be like. Hope we can get most of those 10W before Thursday. The speed today already looked OK though. With 5-10W more I hope to have a little bit of cushion.

He is. And he has been instrumental in getting things up and running on the Mexican side, so to speak. We're really only 5-6 people (including me) that has got this up and running and Rob is one of those people.

Thanks.

And cool that you helped him. Crr seems high still, but hopefully it will get over the next day with removal of the dust.

Temperature will be one of those parameters that will be hard nail down for sure. I have a start time slot of 11-12am local time. Today it was 26C at 11am and 30C at 12am. If it's like that on Thursday it will be a start of 11am for sure.

You need to get a bunch of ST groupies over to clean up the track and wipe the dust off there!!!

By "they" I guess you meant you, Rob, and your coach?...;)

https://www.facebook.com/...26012361235367/?t=16

On target:

Flying!!

If you don't mind me asking what is that app for the splits? Looks useful for track. I notice you have swapped to the walker brother discs too..

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Lucas Hoffman

It was serendipitous. We're all Berkeley faculty (Molly in the Law School, Rob in PoliSci, and me in Demography -- kinda funny that none of us were in Engineering or physics or physiology) and Andres at Beyond Aero connected me to them.

Performance under temp was hard to predict. Molly had done lots of efforts at altitude, she'd done lots of efforts at high temp, but she hadn't done many at altitude at high temp. I did a bunch of calculations balancing off temp and humidity and rho and crr and power and the region of good results seemed larger than the region of bad results, but you never know until you try. They had to make the final call. Afterward, when Rob told me what the actual rho and her actual power had been, I was pretty pleased that the distance calculations were bang on. Science works, bitches.

Heat related performance at altitude should be interesting. As long as the air is below body temperature (sub 38 C) the air is providing a cooling effect, the question is how much. At altitude, at a given true air speed of a rider the air provides less cooling effect than at sea level (conversely you are generating less watts of wasted heat to sustain the same speed at altitude). But in general the air itself will provide less cooling effect at altitude than sea level for a give true air speed, but in practice MTM may be pushing the same number of air molecules out of the way of his body at altitude going faster putting out nearly the same watts. But if he is putting out less watts at altitude, he is generating 4x less heat for the delta watts for a slightly higher true air speed than sea level vs his absolute speed at altitude at sea level watts, so the performance related to heat at altitude may be slightly better if he can ride at lower watts at higher air speed than sea level.

That rationale should work if you know the heat (and humidity) tolerance at sea level. Or rather where heat begins to have a detrimental effect on power production for a 1hr event. It seems to me that optimally you'd want to stay well away from that zone since the advantage of further reducing air density via high temperature is minimal when you are already at altitude. Tire Crr would tend to push you close to that temperature, though.

Also, humidity. Doesn't higher humidity reduce the oxygen in the air? Wouldn't that have a bigger negative effect than the positive of water vapor's lower density? Again particularly at altitude, where additional reductions in density have so little benefit.