Harder into a headwind?

Quoted message said:

Hi All,

I just rode in our club 10km time trial, and while I'm pleased with my
results, I wonder if I might have not used my available power wisely.

I use a PE method to set my pace, and I try to put a little extra
effort into things when the road tilts upward, and ease off a tiny bit
when the road goes down. The idea being that marginal speed increases
at high speeds downhill come at relatively high cost due to the non
linear nature of wind resistance. This is why you also get the most
bang for the buck pouring on a few extra coals up hills due to the
relative absence of this non linear resistance.

But what about headwinds and tailwinds? Today we had a mild tailwind
on the outward leg, and then of course a mild headwind on the return
leg. I kind of over-did it on the way out so things didn't go as well
on the way back. Did this slow me down excessively, or did it not
really matter? With tailwinds and increased speeds, rolling resistance
goes up linearly, so a 6km/h tailwind doesn't give you 6km/h more
speed. But in a headwind, as the speed is lower, the rolling
resistance is a smaller percentage, so 6km/h headwind won't
necessarily slow you down 6km/h. So I suppose it makes more sense to
put more effort into a headwind than a tailwind. But in reality is it
too easy to overdo it and quickly get too much resistance into a
headwind and thus only a marginal speed improvement but at too great a
cost? Is toeing the line too hard to actually do right, so the best
thing to do is just hold back a wee bit? Or would I have had a better
time if I had saved a bit on the way out with the wind so I could have
stomped faster through the wind on the way back?

Joseph

As someone who never did even a halfway decent TT, I'd say that you try
to stay as close to your anaerobic threshold for as much of the race as
you can. Some hills are jammable, and you'll go a bit anaerobic, and
can recover coming down. Real climbs you have to guage your effort. As
far as headwinds, you have to be as aerodynamic as you can be, while
putting in effort near your anaerobic threshold.
"Saving a bit" is tough to say. It seems to imply that you're going
under your anaerobic threshold. Your wind resistance I assume is
relative to your speed relative to the air you're moving through.
Obviously this means you'll be slowed less with a tailwind. I vote for
knowing the course and going as hard as you can without going anaerobic
(until the end).

Steve

--
Mark & Steven Bornfeld DDS
http://www.dentaltwins.com
Brooklyn, NY
718-258-5001

joseph said:

But what about headwinds and tailwinds? Today we had a mild tailwind
on the outward leg, and then of course a mild headwind on the return
leg. I kind of over-did it on the way out so things didn't go as well
on the way back. Did this slow me down excessively, or did it not
really matter?

Depends on both the "mildness" of the wind and how much you over-did
it on the way out.

As a general rule, the time-minimizing strategy given a constraint on
the total number of joules is to adjust your pace so you go a bit
harder uphill and into a headwind, and go a bit easier downhill and
with a tailwind. However:

1. unless the wind is strong, the headwind/tailwind pacing effect is
pretty small and it's usually dominated by the uphill/downhill
effect;
2. pacing is harder when the tailwind is on the outbound leg than on
the inbound leg because you're trying to gauge how to keep something
in reserve for the return;
3. modulating PE is hard to do for a novice; and
4. you probably aren't yet too aware of what your sustainable power
for a 10k is in terms of PE anyway.

What were you time splits?
Was the course dead flat?

Quoted post said:

Hi All,

I just rode in our club 10km time trial, and while I'm pleased with my
results, I wonder if I might have not used my available power wisely.

I use a PE method to set my pace, and I try to put a little extra
effort into things when the road tilts upward, and ease off a tiny bit
when the road goes down. The idea being that marginal speed increases
at high speeds downhill come at relatively high cost due to the non
linear nature of wind resistance. This is why you also get the most
bang for the buck pouring on a few extra coals up hills due to the
relative absence of this non linear resistance.

But what about headwinds and tailwinds? Today we had a mild tailwind
on the outward leg, and then of course a mild headwind on the return
leg. I kind of over-did it on the way out so things didn't go as well
on the way back. Did this slow me down excessively, or did it not
really matter? With tailwinds and increased speeds, rolling resistance
goes up linearly, so a 6km/h tailwind doesn't give you 6km/h more
speed. But in a headwind, as the speed is lower, the rolling
resistance is a smaller percentage, so 6km/h headwind won't
necessarily slow you down 6km/h. So I suppose it makes more sense to
put more effort into a headwind than a tailwind. But in reality is it
too easy to overdo it and quickly get too much resistance into a
headwind and thus only a marginal speed improvement but at too great a
cost? Is toeing the line too hard to actually do right, so the best
thing to do is just hold back a wee bit? Or would I have had a better
time if I had saved a bit on the way out with the wind so I could have
stomped faster through the wind on the way back?

Joseph

A short time trial is a Power Trip

Whilst admittedly 10k is getting a little long, particularly if the
course is somewhat undulating or wind is a factor, but I always found
the best philosophy to be "Get out to the Turn as Fast as you Can, get
Back If you Can"

--
Davey Crockett - No 4Q to Reply

Davey Crockett said:

I always found
the best philosophy to be "Get out to the Turn as Fast as you Can, get
Back If you Can"

If you truly followed that philosophy, I'm guessing you didn't win a
lot of TT's.

Quoted message said:

What were you time splits?
Was the course dead flat?

Quoted message said:

What were you time splits?

There were some cars ignoring the flagman at the turn around point
when I got there, so in the chaos of trying to hammer all the way to
the cone, and to turn without getting killed by a driver too busy
wondering who the crazy guy standing in the middle of the road waving
a red flag was to notice the "Bike Race" sign and the people on bikes,
I forgot to look at my split. I don't have recording capability. I did
notice that I was generally at least 2 cogs away from what I was on
the outbound leg.

Quoted message said:

Was the course dead flat?

Not by my standards, but pretty close I guess. I needed my 12,13, and
14 on the way out, and the 13,14,15 and maybe the 17 once on the way
back. Here's the return leg profile:

http://arbitrary.org/5km.JPG

Joseph

Quoted message said:

joseph said:

But what about headwinds and tailwinds? Today we had a mild tailwind
on the outward leg, and then of course a mild headwind on the return
leg. I kind of over-did it on the way out so things didn't go as well
on the way back. Did this slow me down excessively, or did it not
really matter?

Depends on both the "mildness" of the wind and how much you over-did
it on the way out.

It's hard to say how strong the wind was. The trees were waving
around, and the weather services had forcasts for 5m/s. What the
actual was I don't know. I didn't really overdo it too much, just
enough to not be able to maintain the same intensisty on the way back.

Quoted message said:

As a general rule, the time-minimizing strategy given a constraint on
the total number of joules is to adjust your pace so you go a bit
harder uphill and into a headwind, and go a bit easier downhill and
with a tailwind. However:

1. unless the wind is strong, the headwind/tailwind pacing effect is
pretty small and it's usually dominated by the uphill/downhill
effect;
2. pacing is harder when the tailwind is on the outbound leg than on
the inbound leg because you're trying to gauge how to keep something
in reserve for the return;
3. modulating PE is hard to do for a novice; and
4. you probably aren't yet too aware of what your sustainable power
for a 10k is in terms of PE anyway.

This last point is very important. Since I still haven't bought a
power meter, I try to ride by PE, with occasional glances at the HRM.
I have previoulsy thought my functional threshold was at about 90% of
max hr (about 165), but almost right away my HR was up to 175 (95%)
and I felt good, so I decided to ignore the HRM and just go with it.
Every few minutes I glanced at it and it was where I thought it would
be in the 174-177 range. On the way back it was more like 170-174
until the last 1km where I got it up higher. How much higher and how
quickly I don't know, but as I crossed the line it was at my known max
(184).

Every post brings me closer to buying that power meter...

Joseph

email hidden said:

Quoted message said:

Was the course dead flat?

Not by my standards, but pretty close I guess. I needed my 12,13, and
14 on the way out, and the 13,14,15 and maybe the 17 once on the way
back. Here's the return leg profile:

http://arbitrary.org/5km.JPG

I'd consider that pretty flat. What was your time? 13+ minutes?

in message <[email hidden]>,

(') said:

Hi All,

I just rode in our club 10km time trial, and while I'm pleased with my
results, I wonder if I might have not used my available power wisely.

I use a PE method to set my pace, and I try to put a little extra
effort into things when the road tilts upward, and ease off a tiny bit
when the road goes down. The idea being that marginal speed increases
at high speeds downhill come at relatively high cost due to the non
linear nature of wind resistance. This is why you also get the most
bang for the buck pouring on a few extra coals up hills due to the
relative absence of this non linear resistance.

But what about headwinds and tailwinds? Today we had a mild tailwind
on the outward leg, and then of course a mild headwind on the return
leg. I kind of over-did it on the way out so things didn't go as well
on the way back.

I have no answer, but as it happens my ten tonight was under exactly the
same conditions - brisk tailwind on the outward leg, brisk headwind coming
back. My tactics were to sit up, hands on the hoods, on the outward leg
partly to get a little push from the wind but mainly to stay good and
relaxed while still moving fast. Then, coming back, I got down onto the
tribars and buried myself. I'm not certain this was a good tactic - I
certainly didn't do a good time, even compared to people who are normally
around my time - but it's what I did.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; MS Windows: A thirty-two bit extension ... to a sixteen bit
;; patch to an eight bit operating system originally coded for a
;; four bit microprocessor and sold by a two-bit company that
;; can't stand one bit of competition -- anonymous

Quoted message said:

Davey Crockett said:

I always found
the best philosophy to be "Get out to the Turn as Fast as you Can, get
Back If you Can"

If you truly followed that philosophy, I'm guessing you didn't win a
lot of TT's.

Sho' didn't work for me. ;-)

Steve

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Hi All,

I just rode in our club 10km time trial, and while I'm pleased with my
results, I wonder if I might have not used my available power wisely.

I use a PE method to set my pace, and I try to put a little extra
effort into things when the road tilts upward, and ease off a tiny bit
when the road goes down. The idea being that marginal speed increases
at high speeds downhill come at relatively high cost due to the non
linear nature of wind resistance. This is why you also get the most
bang for the buck pouring on a few extra coals up hills due to the
relative absence of this non linear resistance.

But what about headwinds and tailwinds? Today we had a mild tailwind
on the outward leg, and then of course a mild headwind on the return
leg. I kind of over-did it on the way out so things didn't go as well
on the way back. Did this slow me down excessively, or did it not
really matter? With tailwinds and increased speeds, rolling resistance
goes up linearly, so a 6km/h tailwind doesn't give you 6km/h more
speed. But in a headwind, as the speed is lower, the rolling
resistance is a smaller percentage, so 6km/h headwind won't
necessarily slow you down 6km/h. So I suppose it makes more sense to
put more effort into a headwind than a tailwind. But in reality is it
too easy to overdo it and quickly get too much resistance into a
headwind and thus only a marginal speed improvement but at too great a
cost? Is toeing the line too hard to actually do right, so the best
thing to do is just hold back a wee bit? Or would I have had a better
time if I had saved a bit on the way out with the wind so I could have
stomped faster through the wind on the way back?

Joe, you have a heart rate monitor and you ride as close to your anerobic
threshhold as possible. If you cross the finish line with anything left
you've gone too easy.

I knew a couple US TT champions in their class and a women's TT World
Champion and they all told me that for the championship race they all rode
slightly above their normal threshhold but were so motivated that they could
hold that increased level all the way to the line.

Quoted message said:

On Jun 19, 11:06 pm, "[email hidden]"

Quoted message said:

Quoted message said:

Was the course dead flat?

Quoted message said:

Not by my standards, but pretty close I guess. I needed my 12,13, and
14 on the way out, and the 13,14,15 and maybe the 17 once on the way
back. Here's the return leg profile:

Quoted message said:

http://arbitrary.org/5km.JPG

I'd consider that pretty flat. What was your time? 13+ minutes?

Road bike. 14:56.

Joseph

Joseph said:

Road bike. 14:56.

Clip-ons? Anyway, from your description of gearing and the course
profile, I'd say that either the wind was blowing harder than "mild"
or else you seriously over-cooked on the outbound and ran dry on the
inbound. Or maybe both.

In any event, now you have a target to shoot for. If it's close
enough, make the route part of your training/testing route; if it's
too far away, find a similar low-traffic route that's convenient. I'm
not saying you want to do it at TT pace every day. What you're trying
to do is learn how to pace. As you saw, for a 15 minute race HR is
going to be pretty useless so you're going to have learn how to
calibrate your PE.

Quoted message said:

As a general rule, the time-minimizing strategy given a constraint on
the total number of joules is to adjust your pace so you go a bit
harder [...] into a headwind, and go a bit easier [...]
with a tailwind.

Is that true? I thought the power-speed curve was more linear with a
tailwind, so that an extra effort there leads to a bigger speed
increase than when into a headwind.

Jenko

Jenko said:

Quoted message said:

As a general rule, the time-minimizing strategy given a constraint on
the total number of joules is to adjust your pace so you go a bit
harder [...] into a headwind, and go a bit easier [...]
with a tailwind.

Is that true? I thought the power-speed curve was more linear with a
tailwind, so that an extra effort there leads to a bigger speed
increase than when into a headwind.

Jenko

That's true, but in this case the issue is that there's another
constraint: the course distance is fixed, too. That means that on an
out-and-back you spend less time on the tailwind leg than on the
upwind leg.

Quoted message said:

Joseph said:

Road bike. 14:56.

Clip-ons? Anyway, from your description of gearing and the course
profile, I'd say that either the wind was blowing harder than "mild"
or else you seriously over-cooked on the outbound and ran dry on the
inbound. Or maybe both.

In any event, now you have a target to shoot for. If it's close
enough, make the route part of your training/testing route; if it's
too far away, find a similar low-traffic route that's convenient. I'm
not saying you want to do it at TT pace every day. What you're trying
to do is learn how to pace. As you saw, for a 15 minute race HR is
going to be pretty useless so you're going to have learn how to
calibrate your PE.

No clip ons. The guys I am at the moment most interested in measuring
myself against have been using regular bikes. The best guys have full-
on TT get-ups, but they are in a different league. Some of those guys
are mid 12's. Not this time though, the best time was 13:06.

One problem with pacing is my weight exaggerates the effects of every
undulation of the road, making relatively large speed variations which
are hard to account for. I end up having to change gears a lot, and
the type of resistance (air vs hill) and the subsequent pedal feel are
so different that it is hard to keep the effort level constant. I'm
also used to having to go as hard as I can up hills to try to hang on,
so going at a controlled pace up is not something I have much
experience with. When I do ride a controlled pace up a hill, it is
usually alone at very low intensisty.

I think you are quite right about figuring out how to pace myself. It
seems there is a very narrow band to try to hold, and my PE sensor
isn't sensitive enough. On the way back I wasn't cooked, I just felt
that I couldn't get the effort up as high, until the last 1km where I
stepped it up quite a bit. I was breathing hard and my legs burned at
the finish, but that I think was mostly from the last km. I could have
maintained that pace much longer than 10km, but it felt that if I were
to try to go any faster my legs would have stopped working.

Joseph

Quoted message said:

I think you are quite right about figuring out how to pace myself.

Knowing one's limits comes only with experience, by crossing old
limits. That involves having cautiously ambitious goals, being
realisticly confident. And a craving for endorphins.

--
E. Dronkert

Quoted message said:

Jenko said:

Quoted message said:

As a general rule, the time-minimizing strategy given a constraint on
the total number of joules is to adjust your pace so you go a bit
harder [...] into a headwind, and go a bit easier [...]
with a tailwind.

Is that true? I thought the power-speed curve was more linear with a
tailwind, so that an extra effort there leads to a bigger speed
increase than when into a headwind.

Jenko

That's true, but in this case the issue is that there's another
constraint: the course distance is fixed, too. That means that on an
out-and-back you spend less time on the tailwind leg than on the
upwind leg.

Right. My point is that if you are going to ride 10% harder half the
time (not half the distance), and 10% easier the other half, make sure
the hard half includes the tailwind section.

Jenko

Quoted message said:

Jenko said:

Quoted message said:

As a general rule, the time-minimizing strategy given a constraint on
the total number of joules is to adjust your pace so you go a bit
harder [...] into a headwind, and go a bit easier [...]
with a tailwind.

Is that true? I thought the power-speed curve was more linear with a
tailwind, so that an extra effort there leads to a bigger speed
increase than when into a headwind.

That's true, but in this case the issue is that there's another
constraint: the course distance is fixed, too. That means that on an
out-and-back you spend less time on the tailwind leg than on the
upwind leg.

Is there a bunch of rules of thumb for riding TTs that dumbasses like
me could use. A TT effort cheat sheet?
--
JT
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