Wind article from RBR
Rob Hawks
There is usually something in each issue that I find interesting
(though they dropped my favorite section (racing roundup) and kept
that stupid Scott's Spin section) and today
there was the article below. You can sign up to get the newsletter
mailed to you for free each week here:
http://www.roadbikerider.com/newsletter.htm
One thing I read that at first I scoffed at was the formula that shows
how much a headwind detracts from your speed. I recalled a
particularly heinous ride in the California Central Valley (The 2006
San Francisco Randonneurs 400km brevet in March) when the route took
us directly into a headwind for about 60 miles with sustained speeds
of 25 and gusts up to 35mph. Our forward progress was roughly 8-10mph.
But then I attempted the math. As flat as the terrain was otherwise, I
guess I could have been rolling along at 20+mph (25/2 + 8 = 20.5). I
don't recall ever being so exhausted after a ride. We hit the
turnaround point right at sunset and even in the dark we still were
pedalling at 21mph with the tailwind. I had also heard the point
about perceived headwinds being any wind from greater than 90 degrees,
both left and right of your forward progress, I believe from
Sheldon Brown's writings. Anyway, below is the article. I'd recommend
signing up for the newsletter.
============================
"For every uphill there's a downhill, for every headwind there's a
headwind." -- Florida roadies' maxim
In RBR's poll last week, 10 times more voters said wind is a tougher
cycling challenge than hills.
Why is wind such a drag?
The late cycling physiologist Ed Burke, Ph.D. addressed that question
in his book, "Serious Cycling." He explained that a headwind slows a
cyclist's speed by about half the wind speed. For example, if you're
riding into a block headwind of 15 mph (24 kph) you'll see an average
reduction in forward speed of 7-8 mph (11.2-12.9 kph).
But wind is sneaky. It doesn't need to be coming directly at you to be
perceived as a headwind. It's why a headwind may not stop when you
make a turn. Ask a Florida roadie.
Burke cited wind tunnel studies that showed any wind in the forward
200 degrees of an imaginary circle around a rider will inhibit speed.
Only wind in the trailing 160 degrees will feel helpful.
Here are 11 tips for a better ride on the next windy day:
---Get low. Reduce your frontal area in a headwind by moving your
hands to the drops and keeping your elbows bent and in line with your
body.
---Gear down. Shift to a lower gear (larger cassette cog) so you can
maintain a normal cadence against the wind. Yes, you'll go slower. But
spinning is better for your head and knees than grinding with a slow
rpm.
---Gather a group. It's a huge help on a windy day to ride with
friends. You'll only need to bore into the headwind briefly before
getting shelter in the paceline. Keep pulls short for maximum
advantage.
---Change course. When the gale is blowing, choose a route that
includes natural wind breaks such as woods, hedges, cornfields,
houses, walls and so on. Make it a course with numerous turns so
you're never straight into a headwind for long. If you're limited to
an out-and-back route, start into the wind so it can blow you home
during the second half.
---Change clothes. A blousy jacket will catch the air like a drogue
chute and sound like a baseball card in the spokes. Wear form-fitting
clothing on windy days, perhaps dressing in layers so you can leave
your flappy jacket home.
---Change the time. When windy days are predicted, riding early or
late may mean only battling breezes.
---Stay loose. Keep your shoulders and elbows relaxed to help your
bike stay on course in a gusty wind.
---Stay ready. Anticipate places where the wind is likely to hit you
harder. Example: when passing something that serves as a windbreak, or
when vehicles pass you. A momentary lull in the crosswind could be
followed by a strong blast that catches you off guard and pushes you
off line.
---Keep pedaling. A bike is more stable if the rear wheel is
receiving power. You don't need to pedal hard on a windy descent, but
if you shift to a bigger gear and keep some force on the chain you'll
feel the benefit.
---Be wary of wheels. Windy days are not the time for aero wheels
with tall rims and bladed spokes. They present a larger surface for
crosswinds to push against, making the bike unstable, especially on
fast descents. Standard wheels with low, box-section rims and
conventional spokes are much less susceptible.
---Chant. The wind is my friend, the wind is my friend . . . . Like
riding hills, riding in wind can make you stronger -- if you know the
tricks to turn it into a training advantage. Next week we'll have some
tips for doing that.
Jean-Philippe Battu
When I read the title of your mail, I thought you talked about the last
first edition of RBR
where took place last june between Rennes and Brest and return : Rennes
Brest Rennes
was organized by a cycling club from Rennes (les cheminots rennais) to
show what the
PBP road (on the second half) is !
we were 300 riders to start at 05:00am in the city center of Rennes. We
had to crossed
into the city center, go to the north by a main road to join Tinteniac!
It was the first control and we turned on the left, using the PBP road
towards Loudeac.
As a slow tandem, we were at 11:00am in Loudeac and it was funny to see
at daylight the route
we took during the night and with some more kilometers in our legs !
The route from Loudeac to Corlay was a little bit different from the PBP
route but we discovered
another interesting climbs.
We arrived in Carhaix! the large school was closed, PBP ambiancy was not
here ! We controled
in a bakery and continued !
In the long long climb to Roc Trevezel (but not too steep), we saw the
first rider who came back !
On his recumbent, he was descending very fast, but we had time to say
hello !
Suddenly, we were again alone. When we descended to sizun, we met a
small group in the return leg
with Jean-Gualbert Faburel inside !
We stopped in sizun, met another group which has stopped in a coffee
shop and we ate food we bought
in the supermarket. At this time, we have been joined by a french girl
and his english boyfriend. They were
riding RBR too and we enjoyed to speak with them for a while. I have to
explain we meet them before on
the french forum dedicated to PBP and saw in front of the Rennes station
the day before !
The air was fresh when we arrived in Brest. We crossed the harbour and
get another control in a restaurant.
We decided not to sleep here, but we booked an hotel in Landerneau,
still 30 kilometers to pedal ! Let's go !
We met our girl friend in Landerneau. As she worked on saturday morning,
she couldn't did the first part of the ride
but she joined landerneau by train! We ate together in a pizza and go to
the hotel we booked. We met here three
new young riders who plan to do the next PBP. As they live Grenoble too,
PBP is a challenge for them and they ride
a recumbent. We discovered they left a note for us:
Ready to start at 03:30am ?
Yes, tandem enters in the bedroom, another bedroom for our girlfriend
and we really appreciated the shower before sleeping!
A few hours later, we were (still) eating with our recumbent friends !
Cofee, thea, chocolate, the breakfast was very well
appreciated ! We started together at 04:00am in the night !
We joined the RBR road and joined other riders who have slept in Brest !
We discussed this them in Sizun during a technical stop and continued
the ride.
We arrived in Carhaix just when the bakery opened ! It was still funny
because the brother of baker is a... cyclist ! He did some french
diagonales and we took here another breakfast !
Our girlfriend met another guys she probably knew and continued the ride
together ! The 3 grenoble recumbents were in front of us and we where
still alone in corlay !
We arrived in Loudeac just when another bakery closed !
We arrived at the end of sunday afternoon in Rennes!
For your information, next year, RBR will be replaced by Rennes Dreux
Rennes ! If you intend to ride PBP 2011, you will probably enjoy to
ride Rennes Dreux Rennes as a 600k brevet !
Otherwise, I read your advices against the wind. Gear down is very good
argument: try to pedal at 90 tr/ min, not to force on your legs. Gather
a group may be difficult for riders as us, because whe used to ride on
your own, without any wheels in front of ours ! I am stressed when i
have to follow a bike in front of mine ! I am reserved for the last
advice: My dad's uncle, who rode in 1930, said: "A cyclist must have to
talk during the ride, but not to hiss !
Thank you, I subcribed to the RBR newsletter !
All the best, take care
Jean-Philippe Battu
http://jeanpba.homeip.net
Grenoble
France
Rob Hawks a écrit :
Jack Holmgren
Damon
Britain has very complicated wind patterns due to its topography. In
Scotland especially, you can be riding along a Glen (Valley) and the
wind direction can change halfway because the wind is flowing down a
valley at right angles, It can be mystifying if you haven't checked
the route on a good map. Glencoe is a famous example, 9 times out 10
there will be a wind blowing up it regargless of the overall airflow,
There is a danger that using GPS with downloaded routes that you will
be unaware of changes of direction and local conditions which can help
manage your ride. One tip is to ignore your trip computer during
headwind sections, the depressing sight of the average speed falling
can cause you to push harder than your knees can tolerate, but this
requires an awarenes of likely wind conditions so that you know where
you can pick up time.
Damon.