getting up the mountain

Tamyka Bell said:

adam85 said:

Tamyka Bell said:

In the bike rogaine yesterday, out Samford way, we found a hill that's
20%, total climb was about 150m vertical, so about 750m at 20%,
lovely.
Even in my bailout gear, I didn't get very far!

Tam

Not Mt Oreilly rd by any chance ?
http://www.bikely.com/maps/bike-path/Brisbane-Mt-Oreilly-Rd

Adam

Er, I can't look at that link from here, no www. However it was only a
few km north where Richards Rd, meets Mt Glorious Samford Rd or whatever
it is, near the Samford Rd intersection with the newer shops. The
turnoff was from a street that had a bit park on it and then we went
down a big hill before turning to commence our climb. Oh, and Lot 1 at
the top, was called Madison.

Tam

yes, it was Mt O'Reilly Rd - it made us exhausted just pushing our bikes up
there. It becomes Mayfield Rd a little later, we went up to the junction of
Mayfield Rd & Belinda Pl. Lottebum was pleased to see the top of that one too.

On the way down again my rear brake disk overheated to the point of becoming
corrugated at the bottom - somehow when it cooled down again it was straight
again. Not sure which was the worst, going up or coming down it again!

Karen

--
"Sometimes I think I have a Guardian Idiot - a little invisible spirit just
behind my shoulder, looking out for me ... only he's an imbecile" - Jake Stonebender

Dropbear said:

Donga said:

adam85 said:

I can normally get up there reasonably quickly in under 9 minutes,

Errrmm, Adam, that's not "reasonably quickly". I get rather chuffed
with the low teens.

donga

How is the gradient percentage of a hill worked out?

Roughly as the change in altitude divided by the distance up the hill,
multiplied by 100 for the percentage. So if you went up 100m while
travelling 1km along the road, it would be 10%.

(This is not entirely accurate as the gradient should be the change in
altitude divided by the perpendicular (horizontal) distance travelled,
so that the gradient should be the tangent of the arcsine of that
example... but we'll just apply the small angle approximation and hope
it's valid...)

Tam

Tamyka Bell said:

Dropbear said:

Donga said:

adam85 wrote:

>I can normally get up there reasonably quickly in under 9 minutes,

Errrmm, Adam, that's not "reasonably quickly". I get rather chuffed
with the low teens.

donga

How is the gradient percentage of a hill worked out?

Roughly as the change in altitude divided by the distance up the hill,
multiplied by 100 for the percentage. So if you went up 100m while
travelling 1km along the road, it would be 10%.

(This is not entirely accurate as the gradient should be the change in
altitude divided by the perpendicular (horizontal) distance travelled,
so that the gradient should be the tangent of the arcsine of that
example... but we'll just apply the small angle approximation and hope
it's valid...)

Tam

uuumm...ok... Thanx Tam but where do I get a bike altimeter from, or are
they a feature on some upmarket bike computer/polar hrm?

Dropbear said:

uuumm...ok... Thanx Tam but where do I get a bike altimeter from, or are
they a feature on some upmarket bike computer/polar hrm?

Topo maps are fairly cheap and sufficiently accurate for determining the
altitude of the start and end of a climb. The accuracy is normally +-5m,
which isn't going to make a huge difference over any significant climb.

Or you could just cheat and look up
http://www.cycle2max.com/c2m/c2max.nsf/xtraClimbUnid/7A919FC0E95ECF2BE925717C00379FBE?OpenDocument

--
Dave Hughes | [email hidden]
"SCSI is *not* magic. There are fundamental technical reasons why it is
necessary to sacrifice a young goat to your SCSI chain now and then."
- Daniel M. Drucker

Dropbear said:

uuumm...ok... Thanx Tam but where do I get a bike altimeter from, or are
they a feature on some upmarket bike computer/polar hrm?

either they are based on altimeters and not that accurrate, or gps,
which is rather inaccurate as far as height goes (which is one reason
why SOSW will not work).

So, if you want reasonable accurracy, buy a map.
If you want better accrurracy, look for surveys points top and bopttom
of the climb and work it out. They should be sub 10cm (I think).

Terryc said:

Dropbear said:

uuumm...ok... Thanx Tam but where do I get a bike altimeter from, or are
they a feature on some upmarket bike computer/polar hrm?

either they are based on altimeters and not that accurrate

Define "not that accurate" please. They work on air pressure, which in
most cases, if calibrated within an hour or so, are pretty good,
certainly within 10m or so after a an hour or three, unless there's
been a big pressure change (unusual)

Bleve said:

Define "not that accurate" please. They work on air pressure, which in
most cases, if calibrated within an hour or so, are pretty good, certainly
within 10m or so after a an hour or three, unless there's been a big
pressure change (unusual)

Well if we assume that you're just reading what's on the indicated height,
the accuracy could be anywhere from [censored] to bang on. If you calibrate it
and the weather's reasonably stable then it should be pretty good.

The most accurate way is still to take your shiny altimeter to the map
shop and offer to let them play with it while you sneak a look at their
maps (with apologies to Feynman - on 2nd thought, what's *he* going to do
about it...).

--
Dave Hughes | [email hidden]
We tend to view 'all publicity is gas

TimC said:

And then he would have picked your locks for being so stupid 🙂

Wasn't that Chuck Norris?

--
Dave Hughes | [email hidden]
Good Night Wesley, see you tomorrow.
I'll most likely kill you in the morning

Bleve said:

Hard yakka on a roady, that's for sure. Not sure I'd want to tackle it on
dirt? Wheelspin city?

Depends on the surface. Anderson's fire trail in the Blue Mts must hit 20%
on some sections. Hmm
http://www.geocities.com/volcan271/old_site/andos_profile1.JPG makes it
look like it averages close to 20% over the first 500m or so. There's a
nasty pinch about halfway up that really hurts, and it's easy to lose
traction as you go up the back of a waterbar.

Reversing the Oaks probably hits close to 20% for 50 or so vertical metres
at a couple of spots. The top of Redwire is tough, and the top of BMX hill.

There are a couple of evil firetrail climbs near Turramurra that aren't as
steep but are a lot looser.

--
Dave Hughes | [email hidden]
"They're coming to take me away, Ha Ha
They're coming to take me away, Ho Ho"

Random Data said:

Bleve said:

Define "not that accurate" please. They work on air pressure, which in
most cases, if calibrated within an hour or so, are pretty good, certainly
within 10m or so after a an hour or three, unless there's been a big
pressure change (unusual)

Well if we assume that you're just reading what's on the indicated height,
the accuracy could be anywhere from [censored] to bang on. If you calibrate it
and the weather's reasonably stable then it should be pretty good.

It's accurate enough for me when I fly a light aircraft. Will that do?
🙂
And of *course* you have to calibrate it, but if you're paranoid, you
can get a QNH from the BoM and get it within 5m or so. How accurate do
you need? 5m will be -way- better than any topo map you'll find,
unless the point is right on a contour line and the cartographer has
been *very* thorough.

Quoted message said:

The most accurate way is still to take your shiny altimeter to the map
shop and offer to let them play with it while you sneak a look at their
maps (with apologies to Feynman - on 2nd thought, what's *he* going to do
about it...).

He'd be stumped, if there wasn't a good map of the area. Just as well
he didn't live to see Google Earth!

Peter Signorini said:

TimC said:

How much do you reckon Breakneck Rd in Christmas Hills[1], was?

Just checked in my copy of ESMAP, which has topographic details. It is 500m
at its steepest section and climbs 100m, so 1 in 5, or 20%. Bloody steep!!
But there's probably an even steeper section of 20 or 50 metres in that as
well. You did *very well* to even walk up it!

The climb up Baw Baw has a couple of (short, maybe 30m or so?) 20%
gradient sections.
Hard yakka on a roady, that's for sure. Not sure I'd want to tackle it
on dirt? Wheelspin city?

Bleve said:

Random Data said:

Bleve said:

Define "not that accurate" please. They work on air pressure, which in
most cases, if calibrated within an hour or so, are pretty good, certainly
within 10m or so after a an hour or three, unless there's been a big
pressure change (unusual)

Well if we assume that you're just reading what's on the indicated height,
the accuracy could be anywhere from [censored] to bang on. If you calibrate it
and the weather's reasonably stable then it should be pretty good.

It's accurate enough for me when I fly a light aircraft. Will that do?
🙂
And of *course* you have to calibrate it, but if you're paranoid, you
can get a QNH from the BoM and get it within 5m or so. How accurate do
you need? 5m will be -way- better than any topo map you'll find,
unless the point is right on a contour line and the cartographer has
been *very* thorough.

and anyway, if it's gradient you're after, rather than absolute alt,
you don't need to calibrate it, just record the start and finish
heights, subtract ... it doesn't matter if it's calibrated or not.

Feynman would have made that point more succinctly, of course 🙂

On 2006-08-13, Bleve (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

Peter Signorini said:

TimC said:

How much do you reckon Breakneck Rd in Christmas Hills[1], was?

Just checked in my copy of ESMAP, which has topographic details. It is 500m
at its steepest section and climbs 100m, so 1 in 5, or 20%. Bloody steep!!
But there's probably an even steeper section of 20 or 50 metres in that as
well. You did *very well* to even walk up it!

The climb up Baw Baw has a couple of (short, maybe 30m or so?) 20%
gradient sections.
Hard yakka on a roady, that's for sure. Not sure I'd want to tackle it
on dirt? Wheelspin city?

More locally, Terry's avenue near Belgrave is I think 19%, for about
50m, possibly 100. Definitely wheelspin city on the roady in the wet
🙂

But these are the same tires that I mentioned this morning on the BR
-- trackstanding at the BR corner, on a small slope, on a painted
arrow in the wet, I have once slid backwards while just putting enough
pressure on the pedals to keep my balance.

Anyway, I don't think any of the bunch (some of us were loaded, some
weren't; some were equiped with super short gears, some weren't) made
it all the way up Breakneck -- the road is long and twisty enough that
you can't see all the way up, and I couldn't see the riders who
actually made an attempt at it, while I was still at the bottomish.
But I can't possibly imagine they made it 🙂

--
TimC
Adding features does not necessarily increase functionality -- it just
makes the manuals thicker. --unknown

On 2006-08-13, Bleve (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

Random Data said:

Bleve said:

Define "not that accurate" please. They work on air pressure, which in
most cases, if calibrated within an hour or so, are pretty good, certainly
within 10m or so after a an hour or three, unless there's been a big
pressure change (unusual)

Well if we assume that you're just reading what's on the indicated height,
the accuracy could be anywhere from [censored] to bang on. If you calibrate it
and the weather's reasonably stable then it should be pretty good.

It's accurate enough for me when I fly a light aircraft. Will that do?
🙂
And of *course* you have to calibrate it, but if you're paranoid, you
can get a QNH from the BoM and get it within 5m or so. How accurate do
you need? 5m will be -way- better than any topo map you'll find,

I have absolutely no idea how these sensors work, but it measures air
pressure, right? I'm also really tired (should I have fish and chips
for dinner, or lasagne?), so I could have easily gotten the physics
mistaken, but I find it hard to believe that the sensor can reliably
detect the weight difference caused by the extra 5m column of air
above it (er, at STP, ~24 litres (column of air 5m tall, and 0.0048m^2
in area)=~30 grams; pressure=30grams*9.8m/s^2/0.0048m^2=0.6hpa). And
if it truly is that sensetive, then won't gusts of wind over the
sensor cause it to give false readings? Heck, vibration -- rough
roads -- might even push the strain gauge (?) enough to give slightly
bogus readings.

Anyway, I wouldn't trust it as much as you do.

--
TimC
"Application encountered an error while failing. Error recovered
successfully, proceeding to fail"

On 2006-08-13, Bleve (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

and anyway, if it's gradient you're after, rather than absolute alt,
you don't need to calibrate it, just record the start and finish
heights, subtract ... it doesn't matter if it's calibrated or not.

Feynman would have made that point more succinctly, of course 🙂

And then he would have picked your locks for being so stupid 🙂

--
TimC
"Back off, man. I'm a scientist."
- Dr. Venkman, _GhostBusters_

--
Frank
[email hidden]
Drop DACKS to reply
"TimC" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On 2006-08-13, Bleve (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

Random Data said:

On Sat, 12 Aug 2006 20:46:21 -0700, Bleve wrote:

> Define "not that accurate" please. They work on air pressure, which

in

Quoted message said:

Quoted message said:

Quoted message said:

> most cases, if calibrated within an hour or so, are pretty good,

certainly

Quoted message said:

Quoted message said:

Quoted message said:

> within 10m or so after a an hour or three, unless there's been a big
> pressure change (unusual)

Well if we assume that you're just reading what's on the indicated

height,

Quoted message said:

Quoted message said:

Quoted message said:

the accuracy could be anywhere from [censored] to bang on. If you calibrate

it

Quoted message said:

Quoted message said:

Quoted message said:

and the weather's reasonably stable then it should be pretty good.

It's accurate enough for me when I fly a light aircraft. Will that do?
🙂
And of *course* you have to calibrate it, but if you're paranoid, you
can get a QNH from the BoM and get it within 5m or so. How accurate do
you need? 5m will be -way- better than any topo map you'll find,

I have absolutely no idea how these sensors work, but it measures air
pressure, right? I'm also really tired (should I have fish and chips
for dinner, or lasagne?), so I could have easily gotten the physics
mistaken, but I find it hard to believe that the sensor can reliably
detect the weight difference caused by the extra 5m column of air
above it (er, at STP, ~24 litres (column of air 5m tall, and 0.0048m^2
in area)=~30 grams; pressure=30grams*9.8m/s^2/0.0048m^2=0.6hpa). And
if it truly is that sensetive, then won't gusts of wind over the
sensor cause it to give false readings? Heck, vibration -- rough
roads -- might even push the strain gauge (?) enough to give slightly
bogus readings.

Anyway, I wouldn't trust it as much as you do.

--
TimC
"Application encountered an error while failing. Error recovered
successfully, proceeding to fail"

AT LAST! A question in an area in which I have some expertise. I can answer
with certainty about what I would do in these circumstances:

Have lasagne for dinner.

me

TimC said:

On 2006-08-13, Bleve (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

Random Data said:

On Sat, 12 Aug 2006 20:46:21 -0700, Bleve wrote:

> Define "not that accurate" please. They work on air pressure, which in
> most cases, if calibrated within an hour or so, are pretty good, certainly
> within 10m or so after a an hour or three, unless there's been a big
> pressure change (unusual)

Well if we assume that you're just reading what's on the indicated height,
the accuracy could be anywhere from [censored] to bang on. If you calibrate it
and the weather's reasonably stable then it should be pretty good.

It's accurate enough for me when I fly a light aircraft. Will that do?
🙂
And of *course* you have to calibrate it, but if you're paranoid, you
can get a QNH from the BoM and get it within 5m or so. How accurate do
you need? 5m will be -way- better than any topo map you'll find,

I have absolutely no idea how these sensors work, but it measures air
pressure, right? I'm also really tired (should I have fish and chips
for dinner, or lasagne?), so I could have easily gotten the physics
mistaken, but I find it hard to believe that the sensor can reliably
detect the weight difference caused by the extra 5m column of air
above it (er, at STP, ~24 litres (column of air 5m tall, and 0.0048m^2
in area)=~30 grams; pressure=30grams*9.8m/s^2/0.0048m^2=0.6hpa). And
if it truly is that sensetive, then won't gusts of wind over the
sensor cause it to give false readings? Heck, vibration -- rough
roads -- might even push the strain gauge (?) enough to give slightly
bogus readings.

Anyway, I wouldn't trust it as much as you do.

It's a question of how much do you need to trust it? Not is it
accurate to 5m (although, with appropriate damping and sensitivity, I
can't see why not)