RoadBikeReview.com's Forum Archives - Racing


Archive Home >> Racing(1 2 3 )


wind and time trials(8 posts)

wind and time trialsDougSloan
Jun 6, 2002 2:17 PM
Let's say you are doing a 10 mile out and back time trial. The wind is blowing 10-20 mph in the direction of the road.

Assuming you have a choice, would you estimate the best time would come from starting or finishing with the wind at your back (or does it matter)? Or, would you be faster doing a loop course 3 miles around, alternately having headwind and tailwind, but with more corners?

Any thoughts?

Doug
IntangiblesBipedZed
Jun 6, 2002 2:31 PM
The Cherry Creek TT weekly series is on a 10.5 mile out and back course in April and May. It was a very windy spring in Colorado with no real calm days. Except for 2 races, we had gusty 20-30mph winds most days. In general, times were faster when you started with a tailwind and finished into a headwind. My strategy for TTs tends to be start conservatively (2-3 beats below LT), drop the hammer at the turn around and finish all out with everything I've got left.

With that strategy it was easier to start with a tailwind as I was able to warm up to the exertion and get used to the suffering. By the turn around I was warmed up and used to the pain and able to ramp it up into the headwind. Just as importantly if not more, it is a pychological boost to start fast with a tailwind. Starting into a headwind is demoralizing and I when I know it's going to be slow and painful I tended not to give it that extra effort that's easier when things seem fast (passing guys earlier than last week, etc).
starting withDougSloan
Jun 6, 2002 2:34 PM
Interesting.

Don't you sort of worry when on the first half with a tailwind you look down and see you're averaging 32 mph? I think, "man, the trip back is gonna hurt."

I guess effort is effort, though, and it shouldn't matter what the actual speed it.
preserving vs. salvagingBipedZed
Jun 6, 2002 2:41 PM
Mentally I'm more motivated to preserve a good time from the first half rather than try to salvage a bad time from the first half. If that makes any sense.

For me the hardest part of a TT is the first few minutes when I go from a decent warmup to redline. Once I adjust to redline effort it seems easier.
I dig deeper to preserve...biknben
Jun 7, 2002 5:38 AM
Same as Biped, if I made the turn and saw some insane average I'd dig deep to preserve it.

When someone offers me good and bad news I ask for good news first. It makes the bad news a little easier to take.
interesting derivationDuane Gran
Jun 6, 2002 3:16 PM
There are of course psychological factors, but another angle might be to consider the most efficient use of energy in this situation. Stuart Baird's excellent book "Performance Cycling" examines an out and back TT course with a 3m/s headwind on the first leg.

I'll spare you the numbers (unless you really want them) but he showed that exerting 10% extra effort into the headwind and backing off 10% in the tailwind would save 22 seconds. In another example with a faster rider (one who could maintain about 40kmh/25mph/11ms) the savings were less at just 1.3 seconds.

This is one of those situations where a power meter is your friend. Knowing your absolute capacity for output regardless of the speedometer makes the wind a mostly irrelevant factor for the power-minded racer.

However, if the course is windy and flat, it is advisable to bust a gut up fairly steep hills and recover on the descent. The reason being that speed should dip low enough to reduce the air drag on an ascent. While doubling your speed on the flats requires 8 times as much power (clearly a non-linear relationship) on a steep hill twice as much power can produce nearly twice as much speed.
"The sooner you lick the enemy, the sooner they can be a friend"Canidraftyou
Jun 6, 2002 5:24 PM
Tail winds and Drafting, its all good! In nascar you draft when your Fuel is on "E". I would rather take on the head winds at the start, than at the end. Hotter than Hell in Northern Texas in August. I think is the hardest Century in the Country, with headwinds the last 15 to 20 miles. I was on pace to do a 4 hr and 30 min. Century, and on the last 20 miles all I had to do is finish with a 20 mile an hour ave. I BLEW UP!!! I finished at 4 hrs and 50 min. I yelled out my mothers name for help, I talked back to myself, called the wind every name in the book and even cried, knowing that I wasnt going to complete my goal. It was so hot (106 deg.) and I was so depleted, my tears would dry before they could offer some kinda comfort to my dry chapped skin. I took in 196 oz. of water and lost 6 pounds. I know all about headwind and yeah even lack of endurance for the event at hand. Sorry, I got off the subject, I guess what im saying is HEADWINDS SUCK!!! "The sooner you lick the enemy, the sooner the enemy can be a friend" (ME).

G. Smith
It must be a personal thingPack Meat
Jun 7, 2002 8:15 AM
I did the same TT that Zed did and my times were better when I had a tailwind coming back in. My mindset was that if I go harder at the start I limit my losses because I have a tailwind coming back in. There is nothing worse than being blown and having a headwind you're just screwed. It's also a positive thing for me to see my avg. speed coming up on the last leg of the course instead of desparately attempting to keep it high.