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How flat are The Netherlands?



 
 
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  #61  
Old May 23rd 20, 06:32 PM posted to rec.bicycles.tech
Axel Reichert
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Posts: 28
Default How flat are The Netherlands?

jbeattie writes:

many smaller ranges that are Alps-ish, like the Tetons, don't have
roads through them


Partially the consequence of a big and empty country.

IMO, just getting elevation is neurotic.


It seems to be, but getting elevation strongly correlates with beautiful
landscape and great views (at least for me). And to be able to enjoy,
say, a 3-weeks vacation of pass-bagging in the Alps, you need to have a
certain level of fitness, which occasionally requires doing climbs for
getting elevation (and strength!).

"Everesting" is indeed a strange concept, as is the world record for 24
hours on the turbo trainer ...

Axel
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  #62  
Old May 24th 20, 10:14 PM posted to rec.bicycles.tech
JBeattie
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Default How flat are The Netherlands?

On Saturday, May 23, 2020 at 9:17:24 AM UTC-7, Frank Krygowski wrote:
On 5/23/2020 12:04 PM, jbeattie wrote:

IMO, just getting elevation is neurotic. My son lives in SLC (and was on the Tour of Utah media crew the year after that crash on Guardsman) and has a friend who did 32,000 feet of climbing (divide by three) on a neighborhood street -- over and over just to get his Everest and a bit more. Last weekend,the same guy did Little Cottonwood seven times. https://pjammcycling.com/climb/148.L...nwood%20Canyon And not slowly. His best time put him in 15th place on Strava, with first place being held by Sepp Kuss followed by a bunch of domestic and second-string Euro pros. But I mean really, riding the same climb over and over to rack up elevation? I'd rather be weeding my lawn.


I've never been a fan of climbing. I used to be fairly good at it - or
at least, that's what others told me - but I actually wrote an article
in an old issue of _Bicycling_ magazine about using USGS maps to avoid
the hills.

I have (younger) good friends who frequently do "hill repeats" rides
using some nearby valleys. Climb, descend, climb, descend, repeat until
you drop. I've never been on one of those rides.

It does seem masochistic - much like doing a ride longer than 100 miles
- but I guess the benefit is gaining the strength and confidence to be
able to ride anywhere at all. A couple of those friends are planning to
do yet another tour of the entire Skyline Drive, assuming the virus
situation permits it. I've done only a small part of that route, and I
admit to being jealous.


I just got back from riding on Skyline, although a different one. There's one in California near TK and SMS, too, which is much grander than Portland's Skyline. Ours is a boulevard. We don't have any redwood trees, and the usual climb up from town is probably two or three miles shorter.

The climbs to our little Skyline are steep, relatively short (all under 4 miles) and mostly tree covered until you get to the top -- unless you're riding NW Rocky Point which is, sadly, a clear-cut. https://www.youtube.com/watch?v=5Fzwm4m3ZFI (open brown segments used to be dense fir forest). No rally cars today. I was on the next climb over, Logie Trail -- the downhill view from a car: https://www.youtube.com/watch?v=oy4CugyP-Lk No views going up or down. It was sunny today, and the shade made it the perfect temperature for climbing.


That's a sub-3 mile climb with a maximum grade of 15%, which is like a flat spot in the Alps, but is part of a convenient 45M loop from the house, with the return trip on Skyline chock-full-o shorter climbs, a couple of them pretty nasty.

The good news is I felt pretty good today -- probably because I was riding alone and not getting my ass kicked constantly by my riding buddy. ANY climb is hard if you're red-lining from the bottom. It is truly amazing how pleasant a climb can be at a reasonable tempo, not struggling to breathe and with the right gears.

The bad news is that everyone was out driving or riding -- entire motorcycle clubs. The Miata club was up on Skyline racing around. That doesn't mix well with all the cyclists, particularly on twisting roads with lots of blind corners.

On my way home, I cut around the high school and past the farmers market where the pandemic is taking a holiday. The farmers markets are going great guns and business as usual.

-- Jay Beattie.

  #63  
Old May 25th 20, 09:35 AM posted to rec.bicycles.tech
Rolf Mantel[_2_]
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Default How flat are The Netherlands?

Am 22.05.2020 um 23:41 schrieb Axel Reichert:
Frank Krygowski writes:


L * p^2 may describe a single pass or long climb, but we're much more
often dealing with a seemingly endless series of short steep climbs
followed by short steep downhills.


Downhills do not count. But L * p^2 can (and should) be applied
piecewise for a roller coaster ride. Since these often are steeper than
the epic climbs (and the gradient goes in squared) you will end up with
a higher total difficulty. In my experience this formula (originated in
a Dutch cycling magazine) does an extremely good job in predicting how
you feel after a ride, no matter whether it is Wales or Wallis.


For the real "rolling countryside", you might need to discount the
length of each individual hill by the "speed-assisted" part; on my first
recumbent (a very aerodynamic Kingcycle) I hit 70 km/h at the bottom of
even short hills, and those 70 km/h propelled me almost to the top of
the next hill in "rolling Middle England".
  #64  
Old May 25th 20, 05:11 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Default How flat are The Netherlands?

On 5/25/2020 4:35 AM, Rolf Mantel wrote:
Am 22.05.2020 um 23:41 schrieb Axel Reichert:
Frank Krygowski writes:


L * p^2 may describe a single pass or long climb, but we're much more
often dealing with a seemingly endless series of short steep climbs
followed by short steep downhills.


Downhills do not count. But L * p^2 can (and should) be applied
piecewise for a roller coaster ride. Since these often are steeper than
the epic climbs (and the gradient goes in squared) you will end up with
a higher total difficulty. In my experience this formula (originated in
a Dutch cycling magazine) does an extremely good job in predicting how
you feel after a ride, no matter whether it is Wales or Wallis.


For the real "rolling countryside", you might need to discount the
length of each individual hill by the "speed-assisted" part; on my first
recumbent (a very aerodynamic Kingcycle) I hit 70 km/h at the bottom of
even short hills, and those 70 km/h propelled me almost to the top of
the next hill in "rolling Middle England".


I seem to remember reading somewhere that time trials tend to have
slightly faster speed records where terrain is slightly rolling. I
haven't tried to verify that, but if true, I wonder what's the cause.

--
- Frank Krygowski
  #65  
Old May 25th 20, 11:01 PM posted to rec.bicycles.tech
[email protected]
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Posts: 884
Default How flat are The Netherlands?

On Monday, May 25, 2020 at 9:11:31 AM UTC-7, Frank Krygowski wrote:
On 5/25/2020 4:35 AM, Rolf Mantel wrote:
Am 22.05.2020 um 23:41 schrieb Axel Reichert:
Frank Krygowski writes:


L * p^2 may describe a single pass or long climb, but we're much more
often dealing with a seemingly endless series of short steep climbs
followed by short steep downhills.

Downhills do not count. But L * p^2 can (and should) be applied
piecewise for a roller coaster ride. Since these often are steeper than
the epic climbs (and the gradient goes in squared) you will end up with
a higher total difficulty. In my experience this formula (originated in
a Dutch cycling magazine) does an extremely good job in predicting how
you feel after a ride, no matter whether it is Wales or Wallis.


For the real "rolling countryside", you might need to discount the
length of each individual hill by the "speed-assisted" part; on my first
recumbent (a very aerodynamic Kingcycle) I hit 70 km/h at the bottom of
even short hills, and those 70 km/h propelled me almost to the top of
the next hill in "rolling Middle England".


I seem to remember reading somewhere that time trials tend to have
slightly faster speed records where terrain is slightly rolling. I
haven't tried to verify that, but if true, I wonder what's the cause.

--
- Frank Krygowski


For the same reason that courses with headwinds one way and tailwinds the other tend to have higher averages than TT's with no wind at all. You only have to expend full energy output to sustain a speed for part of the time.
  #66  
Old May 26th 20, 09:35 PM posted to rec.bicycles.tech
Axel Reichert
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Posts: 28
Default How flat are The Netherlands?

writes:

On Monday, May 25, 2020 at 9:11:31 AM UTC-7, Frank Krygowski wrote:

time trials tend to have slightly faster speed records where terrain
is slightly rolling


courses with headwinds one way and tailwinds the other tend to have
higher averages than TT's with no wind at all


Sorry, not from a mechanical point of view.

As a though experiment, if you ride 10 km with 10 % uphill and then
return to the valley, you will have a MUCH lower average speed than when
riding 20 km flat. One reason is that you spend way more TIME (not km!)
with the lower speed than with the faster speed. If you do the trivial
maths, you will see this. Another reason is that a breaking force
(e.g. a headwind) slows you down more than a accelerating force of equal
size (e.g. a tailwind) speeds you up. This is because the Watts needed
go with the 3rd power of the speed.

And it is precisely the reason why it is so tempting (in the flats) to
go "just a little bit" slower: If you slow down by 10 %, you need
roughly 30 % less power, which seems to be a good deal to our weak
minds. (-:

So any additional resistance neither has a benefit, nor cancels out on a
round trip, but is always detrimental to your average speed.

Best regards

Axel
  #67  
Old May 26th 20, 10:54 PM posted to rec.bicycles.tech
[email protected]
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Posts: 884
Default How flat are The Netherlands?

On Tuesday, May 26, 2020 at 1:35:44 PM UTC-7, Axel Reichert wrote:
writes:

On Monday, May 25, 2020 at 9:11:31 AM UTC-7, Frank Krygowski wrote:

time trials tend to have slightly faster speed records where terrain
is slightly rolling


courses with headwinds one way and tailwinds the other tend to have
higher averages than TT's with no wind at all


Sorry, not from a mechanical point of view.

As a though experiment, if you ride 10 km with 10 % uphill and then
return to the valley, you will have a MUCH lower average speed than when
riding 20 km flat. One reason is that you spend way more TIME (not km!)
with the lower speed than with the faster speed. If you do the trivial
maths, you will see this. Another reason is that a breaking force
(e.g. a headwind) slows you down more than a accelerating force of equal
size (e.g. a tailwind) speeds you up. This is because the Watts needed
go with the 3rd power of the speed.

And it is precisely the reason why it is so tempting (in the flats) to
go "just a little bit" slower: If you slow down by 10 %, you need
roughly 30 % less power, which seems to be a good deal to our weak
minds. (-:

So any additional resistance neither has a benefit, nor cancels out on a
round trip, but is always detrimental to your average speed.

Best regards

Axel


Because your average speed going into a headwind is lower the power per unit speed is lower so you don't lose as much to aerodynamic drag. Turning around and heading downwind again you have a lower aerodynamic drag and can achieve a higher speed.

This combination makes out and back TT's in the wind, better to expend as much energy as possible into the wind and then as much as you have left downwind. It's a math problem and actually works.
  #68  
Old May 26th 20, 11:46 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default How flat are The Netherlands?

On 5/26/2020 5:54 PM, wrote:
On Tuesday, May 26, 2020 at 1:35:44 PM UTC-7, Axel Reichert wrote:
writes:

On Monday, May 25, 2020 at 9:11:31 AM UTC-7, Frank Krygowski wrote:

time trials tend to have slightly faster speed records where terrain
is slightly rolling

courses with headwinds one way and tailwinds the other tend to have
higher averages than TT's with no wind at all


Sorry, not from a mechanical point of view.

As a though experiment, if you ride 10 km with 10 % uphill and then
return to the valley, you will have a MUCH lower average speed than when
riding 20 km flat. One reason is that you spend way more TIME (not km!)
with the lower speed than with the faster speed. If you do the trivial
maths, you will see this. Another reason is that a breaking force
(e.g. a headwind) slows you down more than a accelerating force of equal
size (e.g. a tailwind) speeds you up. This is because the Watts needed
go with the 3rd power of the speed.

And it is precisely the reason why it is so tempting (in the flats) to
go "just a little bit" slower: If you slow down by 10 %, you need
roughly 30 % less power, which seems to be a good deal to our weak
minds. (-:

So any additional resistance neither has a benefit, nor cancels out on a
round trip, but is always detrimental to your average speed.

Best regards

Axel


Because your average speed going into a headwind is lower the power per unit speed is lower so you don't lose as much to aerodynamic drag. Turning around and heading downwind again you have a lower aerodynamic drag and can achieve a higher speed.

This combination makes out and back TT's in the wind, better to expend as much energy as possible into the wind and then as much as you have left downwind. It's a math problem and actually works.


Maybe it's time to ask about actual data. Again, I haven't tried to
verify what I heard - that slightly rolling terrain yields faster time
trial speeds. Perhaps my information is wrong. Does anyone know of a
source of appropriate data?

I assume that if it's true, it must be due to some quirk of the power
source - that is, a physical or psychological effect within the rider.
Because the power required is roughly proportional to the cube of the
relative wind speed, a rider shouldn't gain as much on a downhill as he
loses on an uphill.

And for flat courses, contrary to what Tom implies, the energy losses
with headwinds absolutely predict slower times in an out-and-back
course. Similar problems commonly pop up in high school physics or math
courses. Those are usually simple problems based on constant air speed
for planes or constant speed relative to the water for boats. The effect
should be much greater for a rider with a relatively constant power output.

Where can we find time trial results sorted by terrain?

--
- Frank Krygowski
  #69  
Old May 27th 20, 12:12 AM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default How flat are The Netherlands?

On Tuesday, May 26, 2020 at 2:54:50 PM UTC-7, wrote:
On Tuesday, May 26, 2020 at 1:35:44 PM UTC-7, Axel Reichert wrote:
writes:

On Monday, May 25, 2020 at 9:11:31 AM UTC-7, Frank Krygowski wrote:

time trials tend to have slightly faster speed records where terrain
is slightly rolling

courses with headwinds one way and tailwinds the other tend to have
higher averages than TT's with no wind at all


Sorry, not from a mechanical point of view.

As a though experiment, if you ride 10 km with 10 % uphill and then
return to the valley, you will have a MUCH lower average speed than when
riding 20 km flat. One reason is that you spend way more TIME (not km!)
with the lower speed than with the faster speed. If you do the trivial
maths, you will see this. Another reason is that a breaking force
(e.g. a headwind) slows you down more than a accelerating force of equal
size (e.g. a tailwind) speeds you up. This is because the Watts needed
go with the 3rd power of the speed.

And it is precisely the reason why it is so tempting (in the flats) to
go "just a little bit" slower: If you slow down by 10 %, you need
roughly 30 % less power, which seems to be a good deal to our weak
minds. (-:

So any additional resistance neither has a benefit, nor cancels out on a
round trip, but is always detrimental to your average speed.

Best regards

Axel


Because your average speed going into a headwind is lower the power per unit speed is lower so you don't lose as much to aerodynamic drag. Turning around and heading downwind again you have a lower aerodynamic drag and can achieve a higher speed.


Do you mean "you don't experience as much aerodynamic drag"? Also, what about the speed of the headwind? A few weeks back, I rode out to the Gorge in a ferocious wind, including a long open windy climb. I was probably doing 400 watts to go 10mph. It gets windy on the Gorge.
https://www.youtube.com/watch?v=GcP8qK_CSZA Go to :42. This is why you don't want a light bike. You can get 100mph sustained winds out there, not that I ride in them. BTW, it is totally bizarre being blown up hill -- on this road: https://tinyurl.com/y8qlsbv3 It must be how pro tour riders feel -- or eBike owners.


This combination makes out and back TT's in the wind, better to expend as much energy as possible into the wind and then as much as you have left downwind. It's a math problem and actually works.


Or as some say, ride for speed and not power. Peg your power to maintain speed, etc., etc. I have friends who swear by this on hilly TTs. Slaughter yourself on the climbs and recover on the descents. You can do it with headwinds, too, assuming you don't over-spend on the way out. On my recent ride, but for the tail-wind home, I would have taken an Uber. I would rather do a no-wind climb of the same distance than a big wind flat ride. It's soul sucking.

-- Jay Beattie.
  #70  
Old May 27th 20, 02:37 PM posted to rec.bicycles.tech
Axel Reichert
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Posts: 28
Default Pacing, wind, and climbs (was: How flat are The Netherlands?)

jbeattie writes:

On Tuesday, May 26, 2020 at 2:54:50 PM UTC-7, wrote:
This combination makes out and back TT's in the wind, better to
expend as much energy as possible into the wind and then as much as
you have left downwind. It's a math problem and actually works.


Slaughter yourself on the climbs and recover on the descents. You
can do it with headwinds, too, assuming you don't over-spend on the
way out.


I think we have to clearly separate two things he

1. External (wind and climbs are the prime examples, but different surface,
e.g., sand versus ultra-smooth asphalt, would also be possible)

2. Internal (the effort you are spending at a particular point of
the trip, also known as pacing).

Now with regards to 1, if you use

http://kreuzotter.de/english/espeed.htm

go to the "drops" position, enter 400 W, 0 wind, 0 slope and 20 km
(default data elsewhere), you will get 27 min 39 sec for the time. Do
it again with 400 W, 30 km/h wind, 0 slope and 10 km, you will get 22
min 18 sec for the outbound time. Do it again with 400 W, -30 km/h
wind, 0 slope and 10 km, you will get 9 min 22 sec for the inbound time.
In total this 31 min 40 sec for the round trip, so considerably longer
than without wind. The same effect happens if you use +5 and -5 for
slope out-/inbound, respectively. This is left as an exercise to the
reader.

This is the point I was trying to make. External, additional forces WILL
slow you down.

Now with regards to 2, let us assume that you can sustain 400 W only for
10 min, and after that you bonk and have to limp home running on the
emergency power system with 50 W.

First approach is to spend your energy against the wind. With 400 W, 30
km/h wind, 0 slope and 4.483 km your "strong" 10 min are spent. With 50
W, 30 km/h wind, 0 slope and 5.517 km still to go, you will need 45 min
21 sec for the remaining outbound distance. Then it is 50 W, -30 km/h
wind, 0 slope and 10 km go inbound, which need 15 min, 47 sec. In total
that is 71 min 8 sec.

Second approach is to spend your energy with the wind. We know from
above that the inbound leg takes only 9 min 22 sec with 400 W. So you
have 38 sec of 400 W left on the outbound leg, which bring a mere 0.284
km. So 9.716 km to go with 50 W, 30 km/h wind, 0 slope, needing a
whopping 79 min 52 sec. In total that is 89 min 52 sec.

This is the point you were trying to make. Spend your energy there where
you need it most (against the wind or uphill).

In the hilly/windy time trials that were mentioned, these two effects
superimpose. Hills and wind will slow you down, but smart pacing will
give you an advantage over the less smart competition. If, however, you
record the power as a function of time and apply this to a course
without hills or without wind, you will always see that you are able to
achieve a higher average speed: For the above power profile (400 W for
10 min, then 50 W) with 0 km/h wind and 0 slope your "strong" 10 min
last for 7.233 km. 12.767 km to go with 50 W, which take 39 min 5 sec,
for a total of 49 min 5 sec. Much faster than both bad and good pacing.

So in summary, we were both right, but things were a little bit
muddled. I hope this clarifies things.

Axel
 




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