Pittsburgh hills

Article about a race in Pittsburgh's hills. 37% grade, anyone?

http://www.post-gazette.com/stories/...-dozen-663572/

or

http://tinyurl.com/booeuyl

For tech, I suppose we could discuss what equipment you'd use for a 37% grade. On cobblestones!

- Frank Krygowski

On 11/25/2012 6:23 PM, wrote:
Article about a race in Pittsburgh's hills. 37% grade, anyone?

http://www.post-gazette.com/stories/...-dozen-663572/

or

http://tinyurl.com/booeuyl

For tech, I suppose we could discuss what equipment you'd use for a 37% grade. On cobblestones!

- Frank Krygowski


antigravity force field . Or EPO maybe?

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Nov 25, 4:48*pm, AMuzi wrote:
On 11/25/2012 6:23 PM, wrote:

Article about a race in Pittsburgh's hills. *37% grade, anyone?

http://www.post-gazette.com/stories/...-city/with-gri...

or

http://tinyurl.com/booeuyl

For tech, I suppose we could discuss what equipment you'd use for a 37% grade. On cobblestones!

- Frank Krygowski

antigravity force field . Or EPO maybe?

Personally, I would run the 100 yards and save the time and money
necessary to re-gear my road bike. I know that is not part of the
mystique of the ride, but really, it is probably more efficient to
walk or run up 37%, particularly on cobbles in the snow.

Assuming I had to stay on a bike -- I could swap enough parts around
to come up with a triple with a 30/28. That should do it. Maybe use
my cross bike because the long chain stays keep the rear end planted
-- although it is not the lightest bike in the stable. The hard call
would be picking tires -- not too heavy, good grip and float on the
cobbles, but not too slow on the rest of the course -- this is where
some fatty sew-ups would be great.

-- Jay Beattie.

On Sunday, November 25, 2012 9:00:55 PM UTC-5, Jay Beattie wrote:
O
Assuming I had to stay on a bike -- I could swap enough parts around

to come up with a triple with a 30/28. That should do it. Maybe use

my cross bike because the long chain stays keep the rear end planted

-- although it is not the lightest bike in the stable. The hard call

would be picking tires -- not too heavy, good grip and float on the

cobbles, but not too slow on the rest of the course -- this is where

some fatty sew-ups would be great.

If I wanted to use only parts already in my basement, I think I could come up with 24 teeth in front, 34 old SunTour teeth in back (maybe 36), and some 37mm touring tires. I'd remove my handlebar bag and saddlebag and fenders. And I still wouldn't make the climb. :-(

- Frank Krygowski

On 26/11/2012 11:23 AM, wrote:
Article about a race in Pittsburgh's hills. 37% grade, anyone?

http://www.post-gazette.com/stories/...-dozen-663572/

or

http://tinyurl.com/booeuyl

For tech, I suppose we could discuss what equipment you'd use for a 37% grade. On cobblestones!

- Frank Krygowski


Assumptions:

300 W continuous.

60 rpm minimum, 1 rev per second.

175mm cranks.

Percentage gradient is measured as;
gradient = (elevation x 100) / (distance travelled)

Ignoring wind resistance.

Mass of bike + rider = 90 kg.

700c wheels.

Then:

Vertical speed is given by;

P = m*g*dh/dt

300 / (90 * 9.81) = 0.34 m/s

Road speed is then;

0.34 * 100 / 37 = 0.92 m/s, or 3.31 km/h

Gearing required would be;

0.92 = wheel circumference * chainring / sprocket

0.92 approx = 2.014 * 18 / 38

I may need more Watts or a smaller back wheel.

--
JS

"James" wrote in message ...
On 26/11/2012 11:23 AM, wrote:
Article about a race in Pittsburgh's hills. 37% grade, anyone?

http://www.post-gazette.com/stories/...-dozen-663572/

or

http://tinyurl.com/booeuyl

For tech, I suppose we could discuss what equipment you'd use for a 37% grade. On cobblestones!

- Frank Krygowski


Assumptions:

300 W continuous.

60 rpm minimum, 1 rev per second.

175mm cranks.

Percentage gradient is measured as;
gradient = (elevation x 100) / (distance travelled)

Ignoring wind resistance.

Mass of bike + rider = 90 kg.

700c wheels.

Then:

Vertical speed is given by;

P = m*g*dh/dt

300 / (90 * 9.81) = 0.34 m/s

Road speed is then;

0.34 * 100 / 37 = 0.92 m/s, or 3.31 km/h

Gearing required would be;

0.92 = wheel circumference * chainring / sprocket

0.92 approx = 2.014 * 18 / 38

I may need more Watts or a smaller back wheel.

I suspect you have a lot more watts when you consider that whilst 37% this is only 100 yards. In your example above that's roughly 1 minute 40 seconds. My bet is that you could knock out at least 500 watts for the 1 minute it would take you at that power level. It then becomes an optimisation between time, strength, traction and cadence. Not being a hill climb racer I do not have a feel for how that comes out.

Graham.

On 26/11/12 23:18, Graham wrote:

wrote in message
...
On 26/11/2012 11:23 AM, wrote:
Article about a race in Pittsburgh's hills. 37% grade, anyone?

http://www.post-gazette.com/stories/...-dozen-663572/



or

http://tinyurl.com/booeuyl

For tech, I suppose we could discuss what equipment you'd use for
a 37% grade. On cobblestones!

- Frank Krygowski


Assumptions:

300 W continuous.

60 rpm minimum, 1 rev per second.

175mm cranks.

Percentage gradient is measured as; gradient = (elevation x 100) /
(distance travelled)

Ignoring wind resistance.

Mass of bike + rider = 90 kg.

700c wheels.

Then:

Vertical speed is given by;

P = m*g*dh/dt

300 / (90 * 9.81) = 0.34 m/s

Road speed is then;

0.34 * 100 / 37 = 0.92 m/s, or 3.31 km/h

Gearing required would be;

0.92 = wheel circumference * chainring / sprocket

0.92 approx = 2.014 * 18 / 38

I may need more Watts or a smaller back wheel.

I suspect you have a lot more watts when you consider that whilst 37%
this is only 100 yards. In your example above that's roughly 1 minute
40 seconds. My bet is that you could knock out at least 500 watts for
the 1 minute it would take you at that power level. It then becomes
an optimisation between time, strength, traction and cadence. Not
being a hill climb racer I do not have a feel for how that comes
out.



You're probably right.

A while ago someone asked what gradient hill they could ride up with
some wicked small gear. There was a lot of discussion, but I don't
recall anyone coming at it from a power perspective.

--
JS.

James wrote:
:On 26/11/12 23:18, Graham wrote:
:
: wrote in message
: ...
: On 26/11/2012 11:23 AM, wrote:
: Article about a race in Pittsburgh's hills. 37% grade, anyone?
:
: http://www.post-gazette.com/stories/...-dozen-663572/
:
:
:
r
:
: http://tinyurl.com/booeuyl
:
: For tech, I suppose we could discuss what equipment you'd use for
: a 37% grade. On cobblestones!
:
: - Frank Krygowski
:
:
: Assumptions:
:
: 300 W continuous.
:
: 60 rpm minimum, 1 rev per second.
:
: 175mm cranks.
:
: Percentage gradient is measured as; gradient = (elevation x 100) /
: (distance travelled)
:
: Ignoring wind resistance.
:
: Mass of bike + rider = 90 kg.
:
: 700c wheels.
:
: Then:
:
: Vertical speed is given by;
:
: P = m*g*dh/dt
:
: 300 / (90 * 9.81) = 0.34 m/s
:
: Road speed is then;
:
: 0.34 * 100 / 37 = 0.92 m/s, or 3.31 km/h
:
: Gearing required would be;
:
: 0.92 = wheel circumference * chainring / sprocket
:
: 0.92 approx = 2.014 * 18 / 38
:
: I may need more Watts or a smaller back wheel.
:
: I suspect you have a lot more watts when you consider that whilst 37%
: this is only 100 yards. In your example above that's roughly 1 minute
: 40 seconds. My bet is that you could knock out at least 500 watts for
: the 1 minute it would take you at that power level. It then becomes
: an optimisation between time, strength, traction and cadence. Not
: being a hill climb racer I do not have a feel for how that comes
: out.
:
:

:You're probably right.

:A while ago someone asked what gradient hill they could ride up with
:some wicked small gear. There was a lot of discussion, but I don't
:recall anyone coming at it from a power perspective.

And starting speed. If that's the begining of a hill that you can hit
with a running start, you get to trade some of your KE for PE. Even
if it's in the middle of the thill, you'll get some of that, though
not as much.

--
sig 6

On 26 Nov, 01:28, James wrote:
On 26/11/2012 11:23 AM, wrote:

Article about a race in Pittsburgh's hills. *37% grade, anyone?

http://www.post-gazette.com/stories/...-city/with-gri...

or

http://tinyurl.com/booeuyl

For tech, I suppose we could discuss what equipment you'd use for a 37% grade. On cobblestones!

- Frank Krygowski

Assumptions:

300 W continuous.

60 rpm minimum, 1 rev per second.

175mm cranks.

Percentage gradient is measured as;
gradient = (elevation x 100) / (distance travelled)

Ignoring wind resistance.

Mass of bike + rider = 90 kg.

700c wheels.

Then:

Vertical speed is given by;

P = m*g*dh/dt

300 / (90 * 9.81) = 0.34 m/s

Road speed is then;

0.34 * 100 / 37 = 0.92 m/s, or 3.31 km/h

Gearing required would be;

0.92 = wheel circumference * chainring / sprocket

0.92 approx = 2.014 * 18 / 38

I may need more Watts or a smaller back wheel.



1200 of them for 2 minutes is a good place to start IIRC. I remember
that it didn't bother most lads that they were riding a 54" gear up a
slope of 1in4 Even the flyweights coped better with a 25mm rear
tyre (some were using 20mm at times) or 23mm tub(on wet road) probably
about 70 -75 rpm I eventually learnt my better climbing cadence was
at 85rpm, and when I applied this knowledge (after flitting
appropriate FW) could outclimb my mates on short hills. Lower gears
work, but don't go too far. Remember to use the eight muscle actions
in each full crank rotation and keep each active period constrained
within the useful angles. Back, lift, forward, down. At climbing
cadences (of steep hills), there is overlap of the muscle action, but
generally one needs to still keep it to a minimum in order to maximise
climbing speed.

I'd always been good with anaerobic efforts, just not great with the
bike, until learned a few things about my own physiological
capability. After which, I could sprint well, with the right
equipment.

http://www.post-gazette.com/stories/...-dozen-663572/


Very interesting. I lived 5 years in Pittsburgh. I only knew one person who even had a bike. A Schwinn Varsity. I remember the Varsity being highly ranked by Consumer Reports. Not that this dates me or anything.

But, from the article: "(By way of comparison, most hills in San Francisco are in the 20 percent grade.)"

This doesn't strike me as accurate(though it may be). It's been a zillion years since I've ridden my bike up hills in SF but I wouldn't have thought them as a whole as being 20+%.

Guess I could look some up on strava, but I'm hoping someone just sort of knows.