How much power does an average recreational rider generate whenclimbing?

Upon further review, I decided to check a few hills I know with online
tools to get a general idea of how far off my perception is. One hill
I know of that's rather steep came in at a 4-5% grade, which was a
little less than I expected. This is the type of hill I'll get up and
really crank on in order to keep managable cadence, and what I had in
mind when I was thinking 8% grade earlier. Oops...

Then I went to my steepest local hill. this one has kicked my rear
over and over on the singlespeed, with my making it to the top only
once or twice - ever. And that was snaking back and forth at the end,
unable to crank straight up. On this hill on the new bike I'd drop to
my easiest gear and crank hard, and maintain 8ish MPH. I don't think
I could do this for miles, but for the short duration of this hill
it's managable. That's a 12% grade per the web site, and I have a
hard time imagining anything steeper on public roads, especially in
areas where it snows. That same site has another hill which I can
crank up on the SS no problem rated @ 13.5%, and I'm certain that hill
is less steep than the one reported at 12%. These estimates are from
toporoute.com and I can't vouch for how accurate they are. I guess
the only way to tell for sure would be to make a tool such as you
suggested and check for myself.

On Wed, 6 Aug 2008 14:10:43 -0700 (PDT), "
wrote:

Upon further review, I decided to check a few hills I know with online
tools to get a general idea of how far off my perception is. One hill
I know of that's rather steep came in at a 4-5% grade, which was a
little less than I expected. This is the type of hill I'll get up and
really crank on in order to keep managable cadence, and what I had in
mind when I was thinking 8% grade earlier. Oops...

Then I went to my steepest local hill. this one has kicked my rear
over and over on the singlespeed, with my making it to the top only
once or twice - ever. And that was snaking back and forth at the end,
unable to crank straight up. On this hill on the new bike I'd drop to
my easiest gear and crank hard, and maintain 8ish MPH. I don't think
I could do this for miles, but for the short duration of this hill
it's managable. That's a 12% grade per the web site, and I have a
hard time imagining anything steeper on public roads, especially in
areas where it snows. That same site has another hill which I can
crank up on the SS no problem rated @ 13.5%, and I'm certain that hill
is less steep than the one reported at 12%. These estimates are from
toporoute.com and I can't vouch for how accurate they are. I guess
the only way to tell for sure would be to make a tool such as you
suggested and check for myself.

Dear Dan,

Again, I assume that this is all in good faith.

But I'll be astonished if you're cranking up a 13.5% hill on a
single-speed with no trouble and a bad knee.

California has +26% highways like Sonora Pass:
http://www.chainreaction.com/sonora_pass_overview.htm

Cheers,

Carl Fogel

On Aug 6, 3:18*pm, wrote:
On Wed, 6 Aug 2008 14:10:43 -0700 (PDT), "





wrote:
Upon further review, I decided to check a few hills I know with online
tools to get a general idea of how far off my perception is. *One hill
I know of that's rather steep came in at a 4-5% grade, which was a
little less than I expected. *This is the type of hill I'll get up and
really crank on in order to keep managable cadence, and what I had in
mind when I was thinking 8% grade earlier. *Oops...

Then I went to my steepest local hill. *this one has kicked my rear
over and over on the singlespeed, with my making it to the top only
once or twice - ever. *And that was snaking back and forth at the end,
unable to crank straight up. *On this hill on the new bike I'd drop to
my easiest gear and crank hard, and maintain 8ish MPH. *I don't think
I could do this for miles, but for the short duration of this hill
it's managable. *That's a 12% grade per the web site, and I have a
hard time imagining anything steeper on public roads, especially in
areas where it snows. *That same site has another hill which I can
crank up on the SS no problem rated @ 13.5%, and I'm certain that hill
is less steep than the one reported at 12%. *These estimates are from
toporoute.com and I can't vouch for how accurate they are. *I guess
the only way to tell for sure would be to make a tool such as you
suggested and check for myself.

Dear Dan,

Again, I assume that this is all in good faith.

But I'll be astonished if you're cranking up a 13.5% hill on a
single-speed with no trouble and a bad knee.

California has +26% highways like Sonora Pass:
*http://www.chainreaction.com/sonora_pass_overview.htm

I wonder about the 26% designation for Sonora Pass. There are a bunch
of local climbs in the 20% range that are steeper than any thing on
Sonora Pass, IIRC. By the way, I commute over a 16% hill, and one
day, I came across this guy riding up the hill on a fixie. I don't
know if he had a bad knee, but he seemed to be having no trouble
getting up the hill. I could barely stay with him (which was kind of
embarrassing on my multi speed cyclocross bike). Fixed gears are
great for climbing assuming you have the right gear. -- Jay Beattie.

California has +26% highways like Sonora Pass:
http://www.chainreaction.com/sonora_pass_overview.htm

I've seen pictures of that 26% sign, but the book "The Complete Guide to
Climbing (by Bike)" shows Sonora Pass with an average grade of 7% and a max of
21%. ClimbByBike.com gives a max of 18%, with no mile exceeding 11% (which is
still mighty steep):

http://www.climbbybike.com/climb.asp...ountainID=8254

On Wed, 6 Aug 2008 13:37:23 -0700 (PDT), "
wrote:

[snip where grade gets cleared up]

My point is that both bikes in question in the analogy referring to my
father are mountain bikes. The tires and sitting position are very
similar. One is a BST that weighs half a ton, and the other is a high-
end bike that is fairly light. I don’t think rolling resistance is
very different since his wheels will at least match if not outspin
mine in the upside-down wheel spinning test. There’s likely some
effort lost in the bottom bracket and derailers, but I doubt it’s a
whole lot. The difference in effort required to move each bike,
however, is a whole lot.

[snip more]

Dear Dan,

There may be some confusion about rolling resistance.

Reasonable bearings have almost no resistance. You can check this by
taking the chain off the front sprocket, levelling the crank, and
seeing how many pennies you can stack on one pedal before it starts to
drop--there probably isn't a dime's worth of resistance.

The same is true of the rear derailleur pulleys--the lower chain run
is under hardly any load, so there's hardly any chain friction. Flip
the bike upside-down and watch the pulley-arm as you crank the chain
the wrong way, free-wheeling. The pulley arm will hardly move against
the faint spring tension--that's how little drag there is.

Spinning the wheels with the bike upside-down doesn't show anything
useful about rolling resistance. Mostly, it shows wind drag from
spokes and the tire (knobbies are awful). It can show tiny differences
in bearing drag, but the drag is already so tiny that it doesn't
matter. A tire spun in a vacuum would take an amazing time to stop.

The real rolling resistance lies in the deformation of the tire under
load. The endless flexing as the spinning tire bulges at the contact
patch is where the watts are wasted.

This can be detected with spin-down drum tests, where a weight on the
tire mimics the normal load, or with roll-down tests coasting down a
hill. But just spinning in air doesn't show anything useful.

The problem with the drum-test is that it doesn't reflect the watts
wasted jiggling a real rider uselessly up and down on a real road,
while the problem with coasting tests is that a wind too faint to feel
on your cheek will confuse things, as will any tiny change in the
rider's posture--aerodynamics will swamp rolling resistance.

But careful testing shows what theory predicts--the less there is to
flex and the less it flexes, the less power is wasted as the tire
rolls. Thin-walled tires with high inflation roll more easily.

Thread count affects rolling resistance. A sidewall with 60 threads
per inch has more material to flex than a sidewall with 300 threads
per inch--the 300 tpi threads are much thinner, which is why pros use
such tires.

Inflation also affects rolling resistance. At 145 to 200 psi, track
tires don't flex as much as they would at only 90 to 100 psi. On a
smooth track, the harsher ride doesn't matter. On the road,
over-inflation will actually slow the bicycle down--the tire doesn't
flex as much, which is nice, but the rider is bouncing so much that
things slow down.

Again, the weight of the bicycles probably doesn't make much
difference to cruising speed on the flat or even starting off from a
stop sign. But if your dad's bike has underinflated tires that have
more threads per inch, bigger knobs, or thicker rubber, then it's
likely to coast down the same hill more slowly.

If you care, you can test this by putting a cyclocomputer on each bike
and coasting down some long hill a couple of times on a still morning.
Don't pump up any tires, since that would erase much of the
difference. Try to keep the same posture on both bikes--heck, tuck in
as much as you can--and see what the max speed readings are.

Here's an all-numeric calculator that shows the kind of differences
you may see:
http://bikecalculator.com/veloMetricNum.html

Put the watts to 0 for coasting, set the grade to -5% for downhill,
and the default bikes reach 46.31 km/h, about 28.7 mph.

Change the RR from the default 0.005 to 0.003 (a nice road tire) and
to 0.012 (a mountain bike tire) and the speeds change to 47.33 km/h
(about 1 km/h faster) and 42.56 km/h (about 4 km/h slower).

Even a small wind will confuse that kind of difference, but an
underinflated or aggressive MTB tire may have an RR over 0.015, which
knocks the speed down to 40.84 km/h.

In terms of acceleration, the extra 20 pounds doesn't have much effect
on the level, even if we pretend that there's no friction or wind
drag.

F = M * A

A = F/M

If you apply enough steady force (power) to accelerate at 5 meters per
second every second, you'll be going 5 m/s after one second from a
standing start, just over 11 mph.

You'll have covered 2.5 meters.

For the same force, the acceleration decreases as the mass increases.

Your 195-lb mass covered 2.5 meters in a second, accelerating at 2.5
meters/second^2. (175-lb rider + 20-lb bike = 195 lbs)

It's easy to figure out what a 40-lb bike would do with no wind drag
or friction (which only reduce the difference).

5 m/s^2 * 195/215 = 4.535 m/s^2

In the same second, the 20-lb heavier bike would cover 2.267 meters
instead of 2.500 meters, 233 mm less. In other words, after 1 second
the heavy bike would be about 9 inches behind the light bike, which
covered about 100 inches.

Sprint calculators don't handle such tiny differences, but they do
include wind drag and rolling resistance and so forth:
http://www.analyticcycling.com/DiffE...n500_Page.html

The default power curve lets the rider cover 500 meters in 44.2
seconds from a standing start. Add 20 lbs (9.1kg), and the same 500
meters takes 45.3 seconds, 1.1 seconds longer.

But most of that is at cruising speed.

Change to 200 watts max, 199 watts average, 10 seconds everywhere, and
a time for only 50 meters.

The 75 kg bike-and-rider takes 10.6 seconds.

The 84.1 kg bike-and-rider takes 11.0 seconds.

Despite how much heavier the 40-lb bike feels, the acceleration
difference just isn't something that you're likely to notice. It takes
a stopwatch and a lot of trials (you'll vary 0.4 seconds from run to
run in real life) or a theoretical calculator.

Cheers,

Carl Fogel

Michael Press wrote:
In article
,
N8N wrote:

On Aug 6, 12:01 am, "Mike Jacoubowsky" wrote:
| But from a practical standpoint, I weigh 175 (too much for my 6' frame),
|
| not necessarily so.
|
|http://www.reuters.com/article/healt...66953420070316

If I didn't wear *all* of my fat just above the belt, I might agree with you. I know; supposedly a hereditary thing. Arms like toothpicks, legs with skin pretty much stretched across muscle, but a gut. It's just not fair! I could lose 10 pounds and be just fine.

In any event, all my weight loss & gain comes from the same area. The only other variable is water retention, which is largely dependent upon diet. Lots of salt, and what do you know, my feet swell (which I wouldn't notice except when putting on cycling shoes). Real rocket science there.
Heh. Skinny white guys with guts represent.

I'm currently at 190 lbs, I'm about 5'11" - for years I dreamed of
being able to weigh this much. when I was in college I was trying to
stay competitive on the varsity swimming team and was eating
everything in sight to try to keep up with the calories I was burning
in workouts. I never could get over 180 lbs. no matter how hard I
tried.

Now, I look just like you describe - little nothin' arms, legs like
tree trunks, but what the heck is going on around the waist area?

Unfortunately now that my metabolism has slowed some, I just can't
seem to find the time, and more importantly the discipline, to work
out enough to redistribute that newfound mass appropriately...

Pay attention to everything you eat.
The hard core keep a journal of what and how much.
Do not make judgments.

If you are not feeling guilty, you are either a saint or rating yourself
too highly.

Do not attempt changes that make you feel deprived.

Nonsense. Deprivation and suffering in life builds character.

However, depriving children of food on a semi-regular basis can cause
wolf-like behavior around food later in life.

--
Tom Sherman - Holstein-Friesland Bovinia
“Mary had a little lamb / And when she saw it sicken /
She shipped it off to Packingtown / And now it’s labeled chicken.”

On Wed, 6 Aug 2008 20:35:48 -0400, "Barry" wrote:

California has +26% highways like Sonora Pass:
http://www.chainreaction.com/sonora_pass_overview.htm

I've seen pictures of that 26% sign, but the book "The Complete Guide to
Climbing (by Bike)" shows Sonora Pass with an average grade of 7% and a max of
21%. ClimbByBike.com gives a max of 18%, with no mile exceeding 11% (which is
still mighty steep):

http://www.climbbybike.com/climb.asp...ountainID=8254

Dear Barry & Jay,

Grades are always debatable and depend on how things are measured.

Sonora may not have any _mile_ at 26%, but I wouldn't be surprised to
find a much shorter section that reaches 26%.

Fargo Street in Los Angeles is said to be anywhere from 28% to 34%.
It's so short and steep that the grade depends on how close to the top
and bottom you start measuring, as well as which grade calculation
method is used.

At gentler grades, it doesn't make much difference whether the run
part of the rise/run is the hypotenuse or the adjacent side of the
triangle. At steeper grades, the difference starts to exaggerate the
grade.

For a quick example, let's consider a right triangle with an opposite
small side of 2.6 and a long adjacent side of 10:

. end

On Aug 5, 10:22 pm, wrote:
On Tue, 5 Aug 2008 08:55:38 -0700 (PDT), Art Harris
wrote:

I'm not talking about TdF riders, or amateur racers, or even local
"animals."

How much power can a typical, reasonably fit recreational rider
produce on long climbs. For instance, you're doing a 60-mile ride,
cruising along at about 16-17 mph in rolling terrain, and then
encounter a 1-mile 8-percent grade? Obviously, you're going to work
harder on the climb. But how hard can you go on the climb without
blowing up? 150 Watts? 200 Watts? 250 Watts?

Any Power Tap users out there?

Art Harris

Dear Art,

Here's another calculator that might suit your interest:
http://bikecalculator.com/wattsUS.html

Enter weight, grade, and so forth, then put in the mph that you manage
before blowing up, and it predicts watts.

Let's say that your 16-17 mph in rolling terrain translates to 20 mph
on the flats (round numbers are fun). You've mentioned 190 lbs, try
tubulars on the drops (the RR for clinchers vs. tubulars may be a bit
outdated), ignore age because RBT posters only grow more powerful with
age--

Round 169 watts on the flats up to 170 watts.

Now stick 170 watts into the companion watts-to-mph that Kerry
mentioned
http://bikecalculator.com/veloUS.html

It predicts 20.03 mph on the flats, 4.52 mph up an 8% grade.

Let's bump the power to 200 watts--5.30 mph up the 8% grade.

You could reverse things, using the mph that you can hold steadily up
the 8% grade, and get an idea of watts.

When you climb at such low speeds, wind drag doesn't change things
much--higher temperatures and elevations will have hardly any effect
on the speed, even with x.xx precision.

Changing from the drops to the hoods doesn't matter much, either. The
200 watt speed of 5.30 mph up the 8% grade drops to 5.28 mph if you
sit up and grap the tops.

Even small winds won't matter much--at 200 watts up the 8% grade, a 5
mph headwind that knocks 3 mph off the 21.3 mph flat speed will reduce
the 5.30 mph climbing speed only 0.17 mph.

Minor changes in grade don't do much--8.2% drops the 5.30 mph speed
down to 5.18, while 7.8% raises it to 5.43 mph.

Surprisingly, even weight doesn't have as much effect as our obsession
with grams leads us to believe. Add 7 pounds to the 22-lb default
bike, and the 5.30 mph on-the-drops 200-watt speed falls to 5.14 mph.
(In other words, you don't need to toss your water bottle.)

If you want to find Power Tap users, you can join the moderated
wattage group and browse a bit:
http://groups.google.com/group/wattage

You may not even have to join--try clicking on "discussions" on the
link above, or try this link:
http://groups.google.com/group/wattage/topics

Cheers,

Carl Fogel

Carl:
You're over the top and get into complete mischaracterization.

Increase the weight on the climb by 7lb--call it 3% of 200 lb --and
the speed decreases by about the same 3%. Intuitive as a derivative to
me.


Harry Travis

On Wed, 6 Aug 2008 21:30:28 -0700 (PDT), "
wrote:

On Aug 5, 10:22 pm, wrote:
On Tue, 5 Aug 2008 08:55:38 -0700 (PDT), Art Harris
wrote:

I'm not talking about TdF riders, or amateur racers, or even local
"animals."

How much power can a typical, reasonably fit recreational rider
produce on long climbs. For instance, you're doing a 60-mile ride,
cruising along at about 16-17 mph in rolling terrain, and then
encounter a 1-mile 8-percent grade? Obviously, you're going to work
harder on the climb. But how hard can you go on the climb without
blowing up? 150 Watts? 200 Watts? 250 Watts?

Any Power Tap users out there?

Art Harris

Dear Art,

Here's another calculator that might suit your interest:
http://bikecalculator.com/wattsUS.html

Enter weight, grade, and so forth, then put in the mph that you manage
before blowing up, and it predicts watts.

Let's say that your 16-17 mph in rolling terrain translates to 20 mph
on the flats (round numbers are fun). You've mentioned 190 lbs, try
tubulars on the drops (the RR for clinchers vs. tubulars may be a bit
outdated), ignore age because RBT posters only grow more powerful with
age--

Round 169 watts on the flats up to 170 watts.

Now stick 170 watts into the companion watts-to-mph that Kerry
mentioned
http://bikecalculator.com/veloUS.html

It predicts 20.03 mph on the flats, 4.52 mph up an 8% grade.

Let's bump the power to 200 watts--5.30 mph up the 8% grade.

You could reverse things, using the mph that you can hold steadily up
the 8% grade, and get an idea of watts.

When you climb at such low speeds, wind drag doesn't change things
much--higher temperatures and elevations will have hardly any effect
on the speed, even with x.xx precision.

Changing from the drops to the hoods doesn't matter much, either. The
200 watt speed of 5.30 mph up the 8% grade drops to 5.28 mph if you
sit up and grap the tops.

Even small winds won't matter much--at 200 watts up the 8% grade, a 5
mph headwind that knocks 3 mph off the 21.3 mph flat speed will reduce
the 5.30 mph climbing speed only 0.17 mph.

Minor changes in grade don't do much--8.2% drops the 5.30 mph speed
down to 5.18, while 7.8% raises it to 5.43 mph.

Surprisingly, even weight doesn't have as much effect as our obsession
with grams leads us to believe. Add 7 pounds to the 22-lb default
bike, and the 5.30 mph on-the-drops 200-watt speed falls to 5.14 mph.
(In other words, you don't need to toss your water bottle.)

If you want to find Power Tap users, you can join the moderated
wattage group and browse a bit:
http://groups.google.com/group/wattage

You may not even have to join--try clicking on "discussions" on the
link above, or try this link:
http://groups.google.com/group/wattage/topics

Cheers,

Carl Fogel

Carl:
You're over the top and get into complete mischaracterization.

Increase the weight on the climb by 7lb--call it 3% of 200 lb --and
the speed decreases by about the same 3%. Intuitive as a derivative to
me.

Harry Travis

Dear Harry,

Er, what's 3% of ~6mph?

My calculator claims that 0.03 * 6 mph = 0.18 mph.

Looks pretty close to the online bicycle calculator's prediction that
5.30 mph will drop 0.16 mph to 5.14 mph on an 8% grade.

That ~0.17 mph means 0.25 feet per second--about three inches per
second faster.

Where's the mischaracterization? What's over the top?

Cheers,

Carl Fogel

Jay Beattie wrote:

I wonder about the 26% designation for Sonora Pass. There are a bunch
of local climbs in the 20% range that are steeper than any thing on
Sonora Pass, IIRC. By the way, I commute over a 16% hill, and one
day, I came across this guy riding up the hill on a fixie. I don't
know if he had a bad knee, but he seemed to be having no trouble
getting up the hill. I could barely stay with him (which was kind of
embarrassing on my multi speed cyclocross bike). Fixed gears are
great for climbing assuming you have the right gear. -- Jay Beattie.

Numerous riders have completed the Grand Divide Race (GDR) on fixers and
single speeds. Canada to Mexico, 2500 miles, much off-road, 300K+ feet
of total climbing, 16 days or so.