Lance Armstrong time trial postion

[mikesbytes]

Interesting article on the evolution of Lance Armstrong's time trial position

http://ttbikefit.com/blog/?p=808

Interesting to see he no longer keeps his body flat and the particular seat he uses allows him to ride further forward.

[mikesbytes]

Look at this, shoe covers give the same performance improvement as a disk wheel

view the rest of the article here http://www.cyclingtipsblog.com/2010/04/ ... equipment/

[shrubb face]

According to that articles research, i should be able to knock off the 5 minutes i need in the NSW state time trial, just by equipment i own now compared to what i was riding on last year. Given my increased fitness and power as well, this could be good.

[timyone]

id say aerobars should be a lot more than any of those other things, ive ridden them all and the bars made a much more massive difference than the rest!! I really question all these things

[timyone]

(oops no aero frame and wind tunnel experience)

[mikesbytes]

id say aerobars should be a lot more than any of those other things, ive ridden them all and the bars made a much more massive difference than the rest!! I really question all these things

Perhaps there's a variation in the improvements between riders. Another consideration is that when you got the aero bars, it changed the position of your torso.

I'm kinda surprised at the improvement a skin suit makes

[weiyun]

I'm kinda surprised at the improvement a skin suit makes

I think the article refers to those high tech $1000 a piece skinsuits. Cheaper skinsuits are less effective.

[timyone]

well i own ex rider time trial skin suits from confidis, discovery and south australia.com, and they are tight, but im still surprised about the times listed.

[weiyun]

well i own ex rider time trial skin suits from confidis, discovery and south australia.com, and they are tight, but im still surprised about the times listed.

Those are not necessarily the very top end suits. And technology moves on.

[shrubb face]

Well in that image lance is riding in a team discovery skins suit, the same generations as Tim's. A skinsuit makes a large difference to a riders Co-efficent of drag, due to the fact that the human body is the largest area of drag on a bike, so any improvements will have a dramatic effect on the time savings. If i remember rightly somewhere in the region of 90% of the drag on a time trialist comes from the body and the remain 10% from the bike.

After saying all the I doubt any signicant improvements in skinsuit technology have come about in the last 2 or 3 years, as technology advances improvements become smaller and smaller. Im only saying all of this because i own a three year old ex team CSC skinsuit, as ridden in the tour down under and its brilliant.

[weiyun]

Diminishing return is dependent on whether there's a paradigm shift in the underlying technology and I keep an open mind on it. To my understanding, there's been some major advancements in material/fabric technology in the last few years that'll beat those team skinsuits made available to the general public. I read that "dimple" is also being applied to some of these fabrics and the rider's body has far bigger surface area than 2 wheel rims. Even within a team, I wouldn't be surprised if LA and Contador has some kit pieces that's different to the rest of the team and more likely than not, are custom tailored. As suggested by the earlier article, those high end items cost well over $1000 a piece and if your "Team skinsuit" isn't in that price bracket, then I doubt it's the same thing. Also read the following abstract for starter.

Streamlining the time trial apparel of cyclists: the Nike Swift Spin project
Len Brownlie 1 *, Chester Kyle 2, Jorge Carbo 3, Nate Demarest 3, Edward Harber 3, Richard MacDonald 3, Matt Nordstrom 3


Abstract
This paper documents the development of aerodynamic apparel for the Tour de France individual time trial (TT), the Olympic TT, and track cycling races. A wind tunnel and metric balance were used to measure the drag force (Fd) and wind tunnel air velocity on cylinders, limb models, and live cyclists clad in samples or suits sewn with one or more of 200 stretch fabrics. A concurrent measurement of model dimensions and frontal areas provided the non-dimensional drag coefficient (Cd) and Reynolds Numbers (Re) that characterized the ability of the various fabrics and suits to reduce frictional drag and induce a drag crisis (DC) or premature flow transition. DC defines a critical air velocity over the body segments at which the airflow transitions from laminar to turbulent, yielding a smaller wake behind the body segment and a corresponding decrease in Fd. A number of fabrics triggered DC on cylinders and limb segments, reducing cylinder and limb Cd by over 40 per cent. Several methods of lowering the Fd of cycling apparel proved effective, including custom fitting, aligning seams with the airflow, and matching fabric textures to body segments. Repeated drag measurements of the same cycling suit provided a mean drag of approximately 3200 g with a standard error of ±29 g. The final 2005 individual TT suit design, worn by a pedaling cyclist, had a measured drag at 53 kph, which was 125 g less than typical 2001 TT cycling suits worn by competitors (Fd reduction=3.9 per cent). A mathematical model predicts that a drag difference of this magnitude would provide a time saving of approximately 44 s in a 55-km Tour de France TT. In 2002-2005 and 2007, the production version of the Swift Spin TT suit was worn by the winner of the Tour de France; by the women's hour record holder and by road; TT and track cyclists who set four world records, six Olympic records, and won seven medals in individual cycling races at the 2004 Athens Olympics.

[yewenyi]

so we could use some DHBC $50 shoe covers? These gains also apply while riding at high speeds (53 kmh). At the lower speeds I ride at wind resistance is less of the total picture.

[timyone]

Those are not necessarily the very top end suits. And technology moves on.

lol! how much has it improved in the last 5 years? they are pro skin suits bought off a little lad that used to ride with Lance armstrong named Matt white, he doesnt ride any more though, and sold a heap of his clothing, i also own a pair of his ozzy knicks that say australia and discovery on them, it would be the same as what he was wearing for his time trials, has the dimple technology, and you have to bend over to get into it, it has the radio bit in it etc.

Its what they would have been wearing for the tour defrance etc, i had a talk to him about it. How much magical technology is our there weiyun? ive seen the more modern skin suits, our irish ones are pretty up there, they are the same as all the track cyclists we sat near etc, and ive worn recent australian skin suits, which team is it that i have to wear to try this magical technology?

(the discovery one even has the yellow band for the livestrong on the left! lol

[timyone]

which team is it thats wearing it all? ill ask a member of their team on facebook if i have them

[weiyun]

lol! how much has it improved in the last 5 years?

If you want to claim the skinsuit in your possession is of current generation bleeding edge product, then you are entitled to it. I'll continue to reference research articles.

[timyone]

i dont reckon there would be a massive diff.
But yeah ill leave the theory and arguing about crap to you weiyun your so good at it

How about we have a race, you can have every thing you like but have to ride in your drops, ill ride on aero bars, just on my crit bike BMC, and we can have a race. Ill just wear a loose fitting jersy etc.

[timyone]

Biggest Bang For Your Buck?

1. Using aerobars that allow you to get into a tuck position will be the cheapest thing you can do for the aerodynamic benefit. You can get a set of aerobars for $200 and they’ll save you a couple minutes in a 40km TT.

[weiyun]

How about we have a race, you can have every thing you like but have to ride in your drops, ill ride on aero bars, just on my crit bike BMC, and we can have a race. Ill just wear a loose fitting jersy etc.

SOP for settling pub arguments. What else is bigger and faster in your stable? Tell us more...

[timyone]

?
want me to look up some of the big man on the net pics while im at it?

[timyone]

[timyone]

[timyone]

[mikesbytes]

so we could use some DHBC $50 shoe covers?

That thought crossed my mind too.

I don't know if its right or wrong, but shoe covers are cheap, so I might as well start using them

[mikesbytes]

[Karzie]

1 cappucino = 247 seconds

[yewenyi]

so how much time do you loose if you are wearing a billowing rain jacket?

[weiyun]

so we could use some DHBC $50 shoe covers? These gains also apply while riding at high speeds (53 kmh). At the lower speeds I ride at wind resistance is less of the total picture.

On your trike I suspect you'll need a pair of sole/pedal covers, not shoe covers.

[mikesbytes]

I'm wondering if the finding on the shoe covers may be due to the fact that your feet are turning and this increases the effective wind speed. OK, I know I don't know what I'm talking about

[weiyun]

I'm wondering if the finding on the shoe covers may be due to the fact that your feet are turning and this increases the effective wind speed. OK, I know I don't know what I'm talking about

Assuming 180mm crank length, cadence of 100 and simple mechanics, each pedal is moving circularly at 6.79km/h with half the time having a horizontal vector going against the direction of bike travel (6.79km/h max at 12 and 6 positions), while the other leg/pedal is moving in opposite of each other. So that's certainly one aspect. But probably the more important component is the amount of turbulence generated by the shoes and lower limbs and we all know how turbulence can kill the Cd.

[weiyun]

Dimpled fabrics are commercially available these days. I understand that the seams are no longer conventionally sewn together but welded. It's all pretty amazing and about the boundary layer.

[yewenyi]

but the legs are still uncovered and so is the face...

[weiyun]

but the legs are still uncovered and so is the face...

You'll have to come up with ideas for those areas.

[mikesbytes]

acne might help

[Karzie]

but the legs are still uncovered and so is the face...

And cellulite...

[christian]

I think the number on the side of that dimpled suit will pretty much cancel out the advantage. But the again the person without the dimples suit will also have a number on.

[weiyun]

I think the number on the side of that dimpled suit will pretty much cancel out the advantage. But the again the person without the dimples suit will also have a number on.

More to it. I am not sure how valuable such fabric would have in a Cross Country MTB race (as in the photo) where speeds aren't typically high.

[weiyun]

And cellulite...

I always thought hairy legs have the perfect boundary layer condition. But guess proper science has proved me wrong.

[mikesbytes]

Is that my secret? hairy legs

[weiyun]

Is that my secret? hairy legs

As it turned out, hairy legs have the perfect boundary condition for thermo-regulation, not aerodynamics.

[Karzie]

Looks like it wasn't just his aero position or shoe covers. Read the report

[marc2131]