# General Cycling Discussion - How is climbing measured?

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View Full Version : How is climbing measured?

john bono
08-28-06, 09:34 AM
I see a lot of threads where people say, "The ride had X feet of climbing." How is that measured? Is it a)simply the difference between the altitude from the departure point to the destination, b) the height of the highest point during the trip, or c) the sum of every climb during the trip? For example, let's say I rode a loop, which had a 200' hill, a 500' hill, and a 1000' hill. By using a)I wouldn't have had any net climbing(because I returned to the same point), by using b) I would have climbed 1000'(the highest hill), and by using c) I would have climbed 1700'(the sum of the three). Which is the right way to measure climbing?

UmneyDurak
08-28-06, 10:04 AM
It could be either b or c. For example that climb has 1000 feet of climbing, means elevation change is 1000ft. People also say it in context of entire ride. For example I did a century with 15k feet of climbing, obviously all the climbs are added together.

jcm
08-28-06, 10:24 AM
I only casually measure climbing by net altitude gain over the course, since fatigue has a cumulative effect on the day. In the end I measure climbs by pain and suffering. :rolleyes:

If another rider in my club selected the course, I measure things less casually. Chase the bum all the way up, snapping at his heels.

Nightshade
08-28-06, 10:28 AM
The "distance of grade" is much less important than the "percent of grade"
which measures the pull of gravity on the object going up /down the hill.

You can have a hill with a 40% grade that many will have to walk up no matter
how long it is. Then you could have a 2% grade that all fly over. One tactic
used to ease climbing of steep hill is to stretch the distance of the road to convert
that 40% grade to a 2% grade which will "seem" longer because you are on it longer
but the rise per foot will be easier to deal with.

SSP
08-28-06, 10:34 AM
I see a lot of threads where people say, "The ride had X feet of climbing." How is that measured? Is it a)simply the difference between the altitude from the departure point to the destination

No.

b) the height of the highest point during the trip

No.

or c) the sum of every climb during the trip?

Yes.

For example, let's say I rode a loop, which had a 200' hill, a 500' hill, and a 1000' hill. By using a)I wouldn't have had any net climbing(because I returned to the same point), by using b) I would have climbed 1000'(the highest hill), and by using c) I would have climbed 1700'(the sum of the three). Which is the right way to measure climbing?

Your loop would have 1700 feet of climbing (the sum of the three climbs).

Keith99
08-28-06, 10:54 AM
Actually climbing is often done as the sum of all climbs, which can be fuzzy. If there is a 30 foot 'climb' in hte middle of a decent it probably would not be counted. A hundred foot bump in a decent would not get counted by the pros, but many of us would count it. Perhaps the best way to look at it is that it is the total of all the feet where you think of it as being on a climb.

'nother
08-28-06, 12:05 PM
Yeah it is fuzzy. Technically the definition of "total climbing" is "the sum of all positive elevation changes". That part seems pretty easy, but clearly delineating a positive elevation change is the problem, and it depends on the sampling rate of the device measuring elevation (precision of the device may come into play as well, but to a lesser extent).

Something to help you think about it: if I start at 0' and climb to 50', then drop down a small dip to 25', then continue up to 100', I've climbed a total of (50 - 0) + (100 - 25), or 125 feet. OK, pretty simple right?

So now let's pretend my altimeter is taking a sample every 10 seconds. And let's pretend that it takes a sample while I'm at the very top of the first bump, e.g. 50'. Then let's pretend that I descend into the 25' dip, and then back up to the 50' mark of the next bump in under 10 seconds. My altimeter now takes another sample but as far as it knows I'm still at 50' -- the dip (and subsequent climb) did not even register. So as far as it knows, I will only have climbed 100' by the time I get to the top of the next bump.

This is just an exaggerated example but it demonstrates part of the problem. It has nothing to do with the accuracy of the device; a perfectly accurate and calibrated device that only samples once every hour could miss a lot of climbing!

stapfam
08-28-06, 12:43 PM
I do a 100 mile offroad ride each year. You start at Sea level and you finish at Sea level. Zero climbing? No way. In between I have climbed 10,000ft and as far as I am concerned the downhills are a bonus. Or they would be if you could bomb down them. They are almost as tricky as the climbs.

If you do 10,000 ft of climbing you know about it.

cyccommute
08-28-06, 01:12 PM
I think climbing is measured like fish...there's a lot of air added in between the important bits;) I mean, if you're going to count the climbing, shouldn't you also count the descending? It only seems fair.

SSP
08-28-06, 01:46 PM
re: sampling rates and altimeters

Different altimeters have different "triggers" (i.e., how many feet of "up" will trigger a gain), as well as sampling rates. Older models of the Avocet brand had a 30 ft (10 meter) trigger, meaning that you would not get credit for any 25 foot rollers. Newer models have a 3 ft (1 meter) trigger.

FWIW, the rule of thumb when on a group ride is for everyone to compare their altimeter values at the end of the ride. Then, for purposes of logging the ride, you use the one that reports the greatest amount of climbing. :D

'nother
08-28-06, 05:27 PM
FWIW, the rule of thumb when on a group ride is for everyone to compare their altimeter values at the end of the ride. Then, for purposes of logging the ride, you use the one that reports the greatest amount of climbing. :D

Wait, what happened to "...and add 10%"? :p

Anyway yeah triggers, sampling rates, and precision (10' resolution versus 1' resolution) are all at play. I ride with a few folks who are obsessed with getting it "right"...sometimes hard to explain that there's really no "right" when it comes to measuring accumulated climbing.

TomM
08-29-06, 10:39 PM
One tactic used to ease climbing of steep hill is to stretch the distance of the road to convert that 40% grade to a 2% grade which will "seem" longer because you are on it longer
but the rise per foot will be easier to deal with.

This may be a stupid question but I am a flatlander from Florida who doesn't have to deal with hills. How do you stretch the distance? Ride diagonally across the road?

ericgu
08-29-06, 11:05 PM
This may be a stupid question but I am a flatlander from Florida who doesn't have to deal with hills. How do you stretch the distance? Ride diagonally across the road?

Yep. You "tack" back and forth at a 45 degree angle, or even more if you're dying.

webist
08-31-06, 12:51 PM
Yep. You "tack" back and forth at a 45 degree angle, or even more if you're dying.

Now that's an interesting notion.

TomM
08-31-06, 06:34 PM
Yep. You "tack" back and forth at a 45 degree angle, or even more if you're dying.

The GPS track must look interesting.

Pat
09-01-06, 10:08 AM
Yep. You "tack" back and forth at a 45 degree angle, or even more if you're dying.

A 45 degree angle? That would be a 100% grade!! The steepest paved road I have yet seen is 28% and the steepest dirt road was 33%. There are very few paved roads in the USA or anywhere else for that matter that are over 30% or even 20% or even 10%. I even doubt whether there is a paved road that is over 40% for any meaningful distance.

Personally, I don't like tacking. Most people tack into the other lane of traffic. When someone is tacking they are often pretty much beat and they don't really pay attention. I think it is probably better to just get off the bike and walk. If the hill is that steep, it probably will not be very long.

SSP
09-01-06, 10:11 AM
A 45 degree angle? That would be a 100% grade!! The steepest paved road I have yet seen is 28% and the steepest dirt road was 33%. There are very few paved roads in the USA or anywhere else for that matter that are over 30% or even 20% or even 10%. I even doubt whether there is a paved road that is over 40% for any meaningful distance.

Personally, I don't like tacking. Most people tack into the other lane of traffic. When someone is tacking they are often pretty much beat and they don't really pay attention. I think it is probably better to just get off the bike and walk. If the hill is that steep, it probably will not be very long.

I think he meant tack at 45 degrees with respect to the direction of the road...not that it was a 45 degree grade.

Keith99
09-01-06, 11:15 AM
A 45 degree angle? That would be a 100% grade!! The steepest paved road I have yet seen is 28% and the steepest dirt road was 33%. There are very few paved roads in the USA or anywhere else for that matter that are over 30% or even 20% or even 10%. I even doubt whether there is a paved road that is over 40% for any meaningful distance.

Personally, I don't like tacking. Most people tack into the other lane of traffic. When someone is tacking they are often pretty much beat and they don't really pay attention. I think it is probably better to just get off the bike and walk. If the hill is that steep, it probably will not be very long.

Actually over 10% is reasonable common, though usually not for long sections. 20% gets rarer, but usually you can find at least a small climb that steep in any mountian area. In one Vuelta there was a 20% section of a coiuple of miles. (I'm pretty sure it was one that Anquetil rode). Over 30% is harder to find, but Fargo Street in Los Angeles is 33%. The L.A. Wheelman have an annual hillclimb there and it serves to illustrate that tacking has limits. Those trying to tack Fargo Street often end up going down when their uphill pedal hits the road. And of course to tack you eventually have to make that almost 180 degree turn. At which point you are going straight uphill at least for a little while.

withak
09-01-06, 11:16 AM
I guess it's like turning a straight road/trail going up a hill into a buch of switchbacks by zigzagging back and forth across the road/trail.

BluesDawg
09-01-06, 02:46 PM
I measure climbs by the length of tongue hanging out of my mouth when I am on the toughest section.