Road Bike Racing - Jan aero position on the TT bike

Did Lance's dehydration really lead to his 90+ second loss to Jan in the first long TT on this year's tour? Perhaps it played a roll. Perhaps the air-conditioned tent that Jan used helped him in terms of keeping fluid inside his body on such a brutally hot day.

Perhaps.

However, I will submit that Jan's aerodynamic position on his TT steed had something to do with this dramatic win. Look @ the distance between the top of Jan's wheel and his bars compared to the other contenders, including Lance. Look @ where Jan's hands are compared to others. Jan is just WAY lower in the front which has to lead to more speed given the same power output.

This is why I think that Jan will beat Lance in the final TT - by how much is the real question.

Has anyone else noticed this? Talk to me!!! :D

Jan's position - look where his hands and bars are in relation to his front wheel:

Now look @ Lance:

Lance was certainly dehydrated though!

In the first pic you posted of Lance, he's not even using his aero bars so of course he's higher. The second pic his back is alot flatter.

I would say that dehydration would be a major factor in speed, so to only lose 90 seconds is pretty amazing.

And what's with Jan's hand position? Looks painfull to me.

What I see when I look at Jan's position is a huge pocket of resistance to overcome. Obviously JU has the strength to overcome it :) With Lances arm's up position the pocket isn't as large. With as many hours as Lance has spent in the wind tunnel I think he has the best position he can achive.

Zack

Originally posted by skdsl
[B]In the first pic you posted of Lance, he's not even using his aero bars so of course he's higher.

Right, but my point with these photos is not to compare body positions, it's to compare handlebar positions as they relate to a constant - like the front wheel. Sorry if I wasn't clear.

Originally posted by ZackJones
With as many hours as Lance has spent in the wind tunnel I think he has the best position he can achive.

Right, so perhaps he cannot achieve as low of a front position as Jan?

Talk to me folks. I'm trying to somehow relieve my anxiety for Saturday!! :D

Look at how Hugh Jan is compared to Lance.
Moire frontal area = more power needed to force yourself through the air.

Jan may be lower but thats because he need to reduce his frontal area more than lance. Power output suffers as a result. Lance position on the bike is oriented more towards power than outright low drag Cd.

Look at Indurain on the bike. He also sat more upright but he was a narrower physique than Ullrich.

The game is power vs drag. Ullrich won because he coul produce power more consistently than Lance. Lance was dehydrated, not enough medium for his bodily chemical reactions to take place and liberate the stored energy. Not enough energy = not enough power. Not enough power = 1min and 36 secs lossi n a TT. Ullrich's position on the bike had nothing to do with his win.

with all the work lance does in the windtunnel, and with all the special parts (i.e. helmet, bars, etc) designed for him, i find it hard to believe his actual aero position (not the pic you've got of him on the tops-that's on the climb) is the most efficient aero position possible. lance has a different back shape than jan, therefore necessitating a different position on the bike. i think he lost that time because a) jan rode his butt off and 2) he lost 13% of his body weight that day.

John Cobb (the USPS aero guy, who spends all those hours in the wind tunnel) stated that the position JU is in works GREAT....when there is nobody on the bike. So the bike itself has a pretty good advantage, but when you put a rider on the bike that advantage goes away. I doubt Bianchi has anywhere near the budget Postal does, and certainly in the amount of time they had to put the team together they certainly couldn't have spent much time on wind tunnel testing.

Look at that big pocket of his chest, that's really bad. Look how far apart his elbows are, that is catching a ton of wind. Find a picture of LA on the bike properly and you'll see his elbows are much closer together. Jan is just an amazing time trial guy, one of the best in the world with an amazing amount of power.

Here's a thread where he's talking about it;
http://www.bicyclesports.com/forum/ShowPost.aspx?PostID=1732

For Saturday, I'd say JU will win the TT, but Lance won't make the same mistake as he did the other day, you could see LA was dehydrated (anybody catch the white dried junk around his mouth), but I think LA won't loose much of the 1min+ advantage he has now. LA can do some amazing things when he's under pressure.

Andrew

Jan´s position is perfect and couldn´t get any better.
Lance instead sit´s more upright.
- Advantage Ullrich.

:roflmao:

I guess I'll have to go back to uni and relearn my Vehicle dynamics.
Clearly the laws have changed...
I alwats thought it was power vs drag. I guess it must only be drag then:rolleyes:

which ullrich generates more of......

Jan´s position is perfect and couldn´t get any better.
Lance instead sit´s more upright.
- Advantage Ullrich.

Based on what? How did you come to this conclusion? Just as Tim said in his post there are two pieces to this puzzle, power and drag. Jan could put himself into a super-aero position, but it would reduce his power output to the point that us mere mortals could out race him. That obviously doesn't work. He's better off sitting more upright and using those big legs to power him through the air. His handlebars don't work according to a number of people who have looked at them (look at all the big triatheletes, big-name TT bar makers, etc, none of them make a bar like that and they all have wind tunnel experience) and that he is killing his wrists by holding them like that.

He's also loosing time by not using a 3-spoke wheel on the front of his bike. But the differences here are in mere seconds over the course of a 40-50k TT.

Andrew

just have a look at their backs. Ullrich is extremely bended and flexible in addition he powers a higher gear. The profile of saturdays TT-stage is absolutely flat, so, in my opinion, Ullrich will be in the better position.
But 1:07 will be difficult...

Bac,

To return to your original question, if Lance really did
lose 15#s due to dehydration during the first TT then
yes it would account for a large portion of the time he
lost to Jan.
I don't think that Jan is gonna do it this time,
he said in an interview with Frankie he got lucky
on the first TT.

Marty

... and Ullrich is a bit larger (his legs are longer - better lever) than Armstrong.
This is what I think and what I heard.
Jan is not one of the best TT-rider without any reason...

based on the shape of their backs!!??
Heckman where did you study aerodynamics, I'd like to know so I can avoid that college!

the more you are bended (the smaller you are), the less surface the wind will have, or not ?
The result is that you can ride faster.

There is no doubt that Jan has a huge amount of power available to him. But so does Lance. As far as aero goes, there are certain positions that are better than others. But look at that HUGE amount chest of his that is exposed right at the front, that is a big problem and will more than overcome any difference in back shape by a LONG way. The flatter you become on the bike the less power you will be able to transfer to your pedals (lay as flat as you can on your bike, lay your chest down on your handlebars and try and pedal, you are super aero, but of course you can't turn your pedals can you), so you have to compromise. This is why the "ideal" LA position is fairly upright, with his arms fairly close together (to avoid the problem of having that big chest hitting the air), his legs almost rubbing the top tube, and his head straight ahead. LA and USPS have spent probably a couple hundred hours in the wind tunnel in the past 5 years, if they haven't found the ideal position by now, they never will.

Andrew

Telekom and now Bianchi surely will have spent the same time in the tunnel.
I don´t believe that USPS has more scientific insights than other pro cycling teams.
How can Ullrich push those high gears if he´s sitting too "flat" ?

Why would Bianchi have spent so much time in the wind tunnel? It's a new team that was formed only months before the tour? USPS has been in the wind tunnel for the past 5 years, that's a HUGE difference. Besides team Bianchi isn't even riding Bianchi bikes for the TT - http://www.walser-cycles.ch/indexx.htm look familiar, specifically the Model 3? Sure maybe Telekom and Once have probably spent some time in the wind tunnel, unfortunatly JU hasn't been with Telekom for a couple of years.

And how can JU push big gears in a bad position, the guy has got a ton of strength, if he had the "perfect" position it would probably mean a few more seconds over the course of a 40-50k TT. Just simply getting rid of his spoked front wheel and going to a 3 spoke HED would probably get him an extra 5+ seconds on that TT (a few people have measured wheels, and the 3 spoke HED is always at the top by a good margin, except for discs). The real truth is going to come on Sat, hopefully both riders will be at 100% and we can truly see how they compete.

Andrew

each rider will try a position that balances the Powe vs drag relationship. But by far the most significant factor is the power output.
We can safely assume that Lance and jan have similar power to mass ratios;

Their power vs drag tarde offs should produce similar times over the same course if their power vs mass vs drag are similar. So what factor then contributed to Lance being over 1:30 down.
Like he said, His engine was'nt producing enough power because not enough fuel (short cahin fats and sugars) was getting to the combustion chamber (muscle fibre cells) to drive the pistons (legs).

jan's position on his bike is a fixed known quantity. The only difference was power output.
I hope it's clear and not to technical.

two nice pics I found:

2nd:

Here's a good profile shot of LA on the TT from stage 12;

http://a104.g.akamai.net/7/104/1751/0001/www.lancearmstrong.com/pics/2003/tdf03/gw-st12-la.jpg

What you don't see is that his arms are fairly close together (compared to most other riders), he presents a smaller profile by doing that. He's rounded back doesn't hurt very much when it comes to the aero side and the amount of power he can put down is significant (saving 20 watts by being aero does nothing when you loose the ability to put 50 extra watts of power down).

LA's "poor" performance on Stage 12 is going to be from his dehydration (you become that dehydrated and see how fast you ride!), and JU having a "perfect" day. LA has not lost a final tour time trial in the past 4 years, he's never lost to Ullrich in the TT (except for Stage 12)....

Andrew

Look at how the arms come down, and how each guys chest is exposed.

Compare this - LA in pro last years;
http://www.velonews.com/images/tour2002/2580.2520.f.jpg

and JU in stage 12;

And one more, profiles of both;

LA -
http://images.velonews.com/images/gallery/4577.5573.t.jpg

and JU -
http://images.velonews.com/images/gallery/4577.5575.t.jpg

Andrew

To me Armstrongs chest seems to be more exposed than Ullrichs (see photos above).
I still consider Ullrichs position to be better than Armstrong.
Sorry, American guys, you can tell me whatever you want...

I'm not american.........

thats 3-0 to me

Check this link out - http://www.timetrial.org/positionstudy.htm

JU is really getting close to this position;
Wide position (normal saddle and hand position, but placing my elbows out by the brake levers - really bent over and low): area = 0.349
http://www.timetrial.org/images/kwwide1.jpg
(JU isn't quite that wide, but his elbows are very close to the ends of the bars)

and the LA position;
Normal position: area = 0.308
http://www.timetrial.org/images/kwnorm1.jpg
Notice how the arms come down at an angle instead of straight down from the shoulders.

Just food for thought.

Andrew

thanks andrew
an excellent illustration of the point

10 flaming chillies to you mate

Originally posted by Piratello
To me Armstrongs chest seems to be more exposed than Ullrichs (see photos above).
I still consider Ullrichs position to be better than Armstrong.
Sorry, American guys, you can tell me whatever you want...

Hey - I'm American, and I think that Jan has a better position on the bike also. I also want Lance to win his fifth.

IMHO, I think that Lance would have Jan's position if he were able to do so, and still be effective. Lance seems to be in the best aero position that his body will allow - the same with Jan. All other things being equal, this gives Jan an advantage in the ITT. Of course, we know all other things are not equal - hence the rub.

Jan need only average about .5 mph faster than Lance to bear yellow on Saturday, and most likely on Sunday. However, I wouldn't bet against the Texan. He has confidence; he'll most likely know the time splits; he seems to be getting better every day; and he's been know to triumph against all odds, and he looks damn fine in yellow.

Go Lance! :D

Originally posted by Ajay213
Check this link out - http://www.timetrial.org/positionstudy.htm

JU is really getting close to this position;
Wide position (normal saddle and hand position, but placing my elbows out by the brake levers - really bent over and low): area = 0.349
http://www.timetrial.org/images/kwwide1.jpg
(JU isn't quite that wide, but his elbows are very close to the ends of the bars)

and the LA position;
Normal position: area = 0.308
http://www.timetrial.org/images/kwnorm1.jpg
Notice how the arms come down at an angle instead of straight down from the shoulders.

Just food for thought.

Andrew That gives you the flat plate area, now you need a coefficient of drag, and a measure of horsepower, plus something to account for the minor issues with hills.

John Cobb who does alot of the Aero studies
for teams (not just postal) had this to say after
the team time trial:

I thought that the Postals were were in a more natural position for applying POWER.
And after the ITT:


. . . Lance probably was a little more tired than normal at the
start, when that happens he tends to roll his hips back to take
pressure off his hamstrings. I think his aerobars are a little to
long and he's having to reach for his shifters, no big deal, but by
rolling his hips back he gives up some important aero positioning.
Not to take anything away from Ulrich, he had the big motor that
day but I've rarely gotten that low hands position to work well. . .


thats my story and I'm stickin to it.

Marty

IMHO, I think that Lance would have Jan's position if he were able to do so, and still be effective. Lance seems to be in the best aero position that his body will allow - the same with Jan. All other things being equal, this gives Jan an advantage in the ITT. Of course, we know all other things are not equal - hence the rub.

Here's the other side of it as well. You train on your bike 10-20,000 miles a year, you are used to a "type" of position. If you change it that dramatically, it's not going to work for you.

This from a velonews email;
Dear VeloNews;
I noticed that the positions for most of the USPS riders in the team time trial were rather "upright" (shoulders high, sitting on the back of the saddle) as compared to the other teams.

In particular, the position that Bianchi used seemed to be the exact opposite of USPS, being more along the lines of the traditional time trial position (flat back, sitting on the nose of the saddle, shoulders down) - even the aero bars seems to be pointed downward. Was this my imagination or does USPS indeed have a different approach to the TT position?
Bob

Answer from USPS aero' advisor John Cobb of Bicycle Sports:
Postal's approach seems to be working.

There is no way that a Tour rider that trains in an upright position 95 percent of the time, can make long term power on a completely different positioned TT bike.

I'd bet dollars to donuts that none of the Bianchi riders had lower drag than the Postal guys and those (Bianchi) guys are dreamin' if they think those cut off aero' bars work.
John Cobb (Bicycle Sports)

Answer from the other John Cobb in the bike industry, at Security Bicycle Accessories:
I thought that the Postals were were in a more natural position for applying POWER.

In fact, I felt that most teams could have done better times with STI/ ERGO levers on the bullhorn bars instead of the bar end controls on the center mount aero' bar. There was a lot of standing. If you can watch it again, check out Hincapie at the end. That's what won the stage.
John Cobb (SBA)

That's irregardless of all the aero data we already know that says that the position that JU is in is not that aerodynamic because he has his arms WAY to far apart. If he could bring them way in and get his hands up a little higher he'd be doing a lot better. Aerodynamics is a black art/science, something that looks aerodynamic may be very slippery, or having a parachute hanging off your back may be more aerodynamic.


That gives you the flat plate area, now you need a coefficient of drag, and a measure of horsepower, plus something to account for the minor issues with hills.

The drag numbers are there, the wider stance is some 10+% less effecient. Horsepower, well the power output of these guys is kept so secret that I bet it would be easier to find out nuclear launch codes than that :) Hills shouldn't be much of an issue as it's a fairly flat stage.

If we want to get into the real nuts and bolts JU needs to put down more power just to stay "even" with LA, he's a bigger rider (needs more power to accelerate after every corner), with a less aero position that doesn't get all his power down, riding a bike that doesn't have all the aero goodies on it with a less than aero helmet, and who knows if he's wearing the truly fancy skin suit. So yes, JU needs to ride roughly .5mph faster to get the job done, but does he have that much more power to do it?

If LA and USPS were telling the truth about LA's dehydration (they probably embellished a little bit) that would equal some 20-25% loss of power output from LA on Stage 8. It's going to be interesting on Sat for sure, and I truly wouldn't be suprised if it goes either way, but JU's position is not what caused him to win on the last ITT.

Andrew

Originally posted by Ajay213
There is no way that a Tour rider that trains in an upright position 95 percent of the time, can make long term power on a completely different positioned TT bike.

Perhaps Jan did an inordinate amount of rides on his TT bike during his suspension for doing X? I dunno. I do know that he convincingly beat ever rider in the tour in the first ITT.

I'm still betting on Lance, but if Jan wins - I'm giving the credit to his more aero stance on the bike. Is it Saturday yet? :D

Perhaps Jan did an inordinate amount of rides on his TT bike during his suspension for doing X? I dunno. I do know that he convincingly beat ever rider in the tour in the first ITT.

Then he'd have problems on his regular bike... :) (somebody has to be devil's advocate here). LA has pulled out similiar performances during TT's, so it's truly going to be a grudge match between these two guys.

I'll even go so far as to predict that LeMonds speed record is going fall for this TT (despite the fact that it's a longer stage than that fateful TT into Paris in 89).


I'm still betting on Lance, but if Jan wins - I'm giving the credit to his more aero stance on the bike. Is it Saturday yet?

If Jan wins, I'm giving credit to the fact that first he really, REALLY wanted it and that he was able to pedal that much faster knowing that he would have really kicked ass if he were really riding in a truly aero position, when an aero expert says (along with the rest of the aero gurus who all pretty much get to the same position);

"I'd bet dollars to donuts that none of the Bianchi riders had lower drag than the Postal guys..."

I gotta go with it...

So the question is will JU be able to pull out another super TT even after putting 110% in the mountains (remember for the first TT he kept losing time to LA in the mountains). Will LA be strong enough as well, and will he have another dehydration problem? Will either of them ride into bad luck, we're close enough that a flat tire during the TT will sway the results.

Andrew

Originally posted by bac
Right, so perhaps he cannot achieve as low of a front position as Jan?

Talk to me folks. I'm trying to somehow relieve my anxiety for Saturday!! :D

That's correct. Chris Carmichael stated in one of the interviews that Lance has very tight lower back and ham string muscles and can't get into as an aero position as other riders.

It is going to be an extremely tight race between the two. Personally I do not believe JU can pull 1:07 out of Lance. If by chance he does he will have certainly earned the win.

Zack

The problem is not whethre Lance can get into the aerodynamically optimum position (and IMO he's pretty close) it's whether the position he's using allows him to generate enough power to drive him forward. The most aero position for a ccyclist is the supine position ie laying on your stomach but I'llbet you'll find it had to generate enough power form there to go very fast or accelerate enough out of corners for it to be of benefit.

Also an aerodynamic position doesn't have to look aero ie low head high flat back. Thats 80's theory. The human body and bike synergy interacts with the airflow in a 3 dimentional plane. How the air flows around the head and where it goes to frm there is also very important.

With lances position the air flow leaves his helmet and flows down his back and witha drop in pressure ie back to atmospheric so little turbulence is generated.
With Ullrich' position the air flow leaves his head and exits onto his back which is stilled humper so there is stil and increase in pressure and then leaveshi back and the srop in pressure is fast resulting in turbulence.

Lances position is the best for the compromise between aero efficiency and power generation. Ullrish is too low on the bike. The bike moves aroun too muchunder him which crets more turbulence.

His saving grace is that he is a very powerful rider and that counted for a lot in the first TT.

Originally posted by Ajay213
The drag numbers are there, the wider stance is some 10+% less effecient. Horsepower, well the power output of these guys is kept so secret that I bet it would be easier to find out nuclear launch codes than that :) Hills shouldn't be much of an issue as it's a fairly flat stage. I included the hills to be comprehensive, but I agree that the overwhelming issue is the power/drag ratio, and drag is Cd*A*k*v**2, Given roughly comparable v and A, then we are merely looking for Power/Cd.


If we want to get into the real nuts and bolts JU needs to put down more power just to stay "even" with LA, he's a bigger rider (needs more power to accelerate after every corner), with a less aero position that doesn't get all his power down, riding a bike that doesn't have all the aero goodies on it with a less than aero helmet, and who knows if he's wearing the truly fancy skin suit. So yes, JU needs to ride roughly .5mph faster to get the job done, but does he have that much more power to do it?

If LA and USPS were telling the truth about LA's dehydration (they probably embellished a little bit) that would equal some 20-25% loss of power output from LA on Stage 8. It's going to be interesting on Sat for sure, and I truly wouldn't be suprised if it goes either way, but JU's position is not what caused him to win on the last ITT.

Andrew Meaning-if Lance is healthy it is almost impossible for Ullrich to win

Body position on a bicycle is a surprisingly subtle matter when it comes to fine tuning at the pro level. As in many cases of applied fluid dynamics, one has to get into the tunnel and see for for sure just what helmet, for example, works best with what position on what guy. There aren't a lot of certainties available from a priori speculation.

But there are some. And I have to agree that Jan's position seems better overall in reducing drag. Whatever might be said about something called "pockets" on Lance's behalf, Jan's back is flatter. That's very important, in that it eliminates the low pressure areas behind shoulders and upper back that result from a more upright profile. That's a very big deal compared to more subtle adjustments that teams spend a lot of dough on. Jan's hands are not that wide apart to make his position worse than Lance's, either.

A drag advantage would be decisive only if we knew Jan's power were equal to or greater than Lance's, though. And we'll find that out Saturday.

I'll tell you what- all of you are full of B.S.!
You don't know who is "more aero" because they have not done a wind tunnel test on both riders in the same wind tunnel and same conditions.
Who cares who "looks more aero"?! That doesn't mean jack! Ullrich is a world TT champion and knows what works for him. Lance know what works for himself too.

Give me a break with all this lame armchair analysis from photographs (which distort an image based on lens, lighting, motion, f-stop used and film used- not to mention the quality of digital transfer).

Sorry, none of you can say who is "more aero". If you could fine tune aerodynamics with photographs, we wouldn't need to put things in WIND TUNNELS, now would we? Hello?!

all excuses are equal. It is time that counts.

You don't know who is "more aero" because they have not done a wind tunnel test on both riders in the same wind tunnel and same conditions.

That's right, none of us knows who is more aero. Unfortunatly there are people in the world with lots and lots of experience with these things and they say he's not aero. These are people who have spent decades positioning people on bikes, people who have won at national/pro levels, etc.


Who cares who "looks more aero"?! That doesn't mean jack! Ullrich is a world TT champion and knows what works for him. Lance know what works for himself too.

And when Ullrich won the gold he didn't position himself like that.


Sorry, none of you can say who is "more aero". If you could fine tune aerodynamics with photographs, we wouldn't need to put things in WIND TUNNELS, now would we? Hello?!

You are absolutely correct, except that we know how both riders sit on the bike and we have drag numbers for both styles. Nevermind the fact that everybody who does test positions in a wind tunnel has never come up with a position like Jan's does tell us something doesn't it? Showing a photograph to illustrate a point is one thing (since it seems most people have not gone and read any of the links posted), and you are 100% correct, it doesn't mean jack other than to show the two different styles of riding.

In any case it doesn't really mean anything because it's all going to come down to who has more power in their legs and who wants the win the most, as it almost always does.

Andrew

You are absolutely correct,

it doesn't really mean anything

Andrew

Thank you. You are all talking out your a$$.:D

I still think Jan is more aerodynamic on the bike. :cool:

Thank you. You are all talking out your a$$.

Of course we are...


I still think Jan is more aerodynamic on the bike.

And some people still believe in Santa Claus (who does not have an aerodynamic sleigh)....still don't mean it's true :D

Andrew

perhaps looking for excuses why Lance lost the TT is not the answer.
Accept he had a bad day and you'll all be much happier.

I believe Ullrich won the stage in a less efficient position overall.

Lance has spent a lot of time in the wind tunnel perfecting his position. I think he knows what he's doing.

Kula