msheron

I know this has been covered but here is a chart showing a climb I did in Saluda, NC for about a 4 mile climb which equated to 39.2% grade climb.

Really a leg burner. The ride down the other side of the mountain was a thrill however!

furiousferret

wtf? I have a 24% by my house and I can't imagine anything over 30%. It seems that anything over that you'd fall over if you got out of the saddle.

GuitarWizard

**** that ****, dude.....

celticfrost

From your attached graph, it does look hilly. But 39.2% ??!! How are you computing the grade?

msheron

Garmin 305 Edge with MB software for adjustments to fine tune your ride.

Machka 

I highly doubt it was 39.2% considering the steepest road in the world is Baldwin St. in New Zealand is 38%. If your calculations are correct, you'd better be contacting the Guiness Book of Records.

https://mappic.org/pictureInfo.php?tid=425
https://www.ourshop.co.nz/baldwinstreet.htm
https://www.bikereader.com/contributo...ley/hills.html

celticfrost

But at ~2.5 miles you're at ~900ft and at ~7.5 miles you're at ~2200ft. That's 1300ft in 5 miles, which is about 5% grade over those 5 miles.

*edit* --- still though, 5% for 5 miles is no easy task!

msheron

Really...................anyone else there find descrepancies with their Garmin Edge using MB?

All I know is it is straight up!

celticfrost

You (or your Garmin) may be mis-reading the line for miles. At ~ mile 7.5, you're at 2200ft, not at a grade of 39% !

Stjtoday

From the looks of your graph.. you have suffered a major earthquake.

Machka 

Cyclists go to Baldwin St. to ride the hill there because it is a tourist attraction and such a challenge. A friend of mine went. He is an incredible climber and very strong cyclist and it took him three tries to make it to the top, and Baldwin St. isn't that long.

I've attempted a 25% (1 in 4) grade in Wales, and couldn't even begin to think about riding up ... even walking the kilometer up was a long and strenuous challenge. See the Long Mynd photos: https://ca.pg.photos.yahoo.com/ph/mac...=/9498&.src=ph

If there were a hill at 39%, it wouldn't be a mere "leg burner" .... all your muscles would be screaming and your lungs would be on fire. And I doubt there are very many people in the world who could keep that going for 4 miles.

ElJamoquio

** ***** **** , *** ****** ****.

(Translation: I agree).

ElJamoquio

To answer the question, the largest grade on my rides is about 3%. Those darn overpasses.

Machka 

That's how I read that chart ... I believe that's how most elevation charts are read. If you convert 1300ft into miles that's 0.246 miles. 0.246/5 = 0.0492 = ~5%

If it were a 39% grade over approx. 5 miles that would be 5*.39 = 1.95 miles or an elevation gain of approx. 10, 300 feet in 5 miles.

thad

Your edge is off or you are reading the graph wrong, I can't make any sense of that graph so its probably the latter.

Ranzak

Mscheron, check out this link: https://www.freewheelers.info/climbs/ this info is reputed to be fairly accurate

RockyMtnMerlin

The pro's really complain about the Angliru in Spain and it is a max of about 22%. I think it was Manuel Beltran who said, "Just make sure you don't stand up and pedal because you will flip over backwards!" Three years ago they did it in the Vuelta de Espana and it was raining. Racers all used really small chainrings and really big sprockets. The organizers were afraid that the some of the non AWD team cars could not make it up the grade in the heavy rain!!!!!!!!!!!!!

KevinF

Well, the first question is how does this Garmin product measure altitude? Is it barometric or is it GPS based? GPS based altitude readings are generally worthless: https://gpsinformation.net/main/altitude.htm.

If it's barometric-based (i.e., somewhere in the unit there's an air pressure sensor) then you most likely encountered some bizarre micro-climate. Altitude does affect air pressure, but I imagine there are a lot of other things that could cause variations in air pressure between two close points.

Reliably determining altitude seems to be a rather tricky problem (at least for portable bike / ski / hike devices).

Mojo Slim

Here's a picture of one of our local testers. The sign says "Caution. +15% next 3 miles".

RockyMtnMerlin

Now that is a daunting sign. I have never seen one like that in Wyoming. Perhaps the Wyoming Department of Transporation is too smart for that. Or maybe its because we have so few citizens that we don't have many roads. In fact, we have only 490,000 people in 97,000 square miles.

26mi235

Clearly this ride is nothing close to 39%; it is not much more than one-tenth that amount (someone else has pointed out that 39% for 5 miles gets you over the rockies much less anything east of the Big Easy.

Why do you get this result? One possibility is given by the highly erractic grade measurement, with a 30%++ 100feet followed by a -20% 100 feet (did you have the meter on the outside edge of you rim??). Also notice that the vertical and horizontal scales differ by a factor of 75 or so and if you stretched the horizontal distance by that factor you would see that you mountain is not particularly steep, much less the #1 climb around.

ericgu

You're reading the graph wrong. The grade percentage is the really jagged line, and what you're seeing is the noise that is inherent in GPS altitude measurements.

cyclintom

Is it just me or does anyone else think that the sine of the hypoteneuse equal the opposite so that 4 miles at 39.2% would mean a climb of about 6200 feet or over a mile high?

Mt. Michell is almost 6,700 feet so that doesn't make it impossible but ........

Here's a clue - unless you're some sort of climber, going up 18% for more than a couple of hundred feet is HARD HARD HARD.

The longest sustained climb I've done on the road was 3 miles of unbroken 13% and I could barely move when I hit the top despite being in racing shape at the time.

Marin St. in Berkeley has a one block section of 24% that I climbed on a mountain bike with a 24/34. They paved the street going downhill only.

The Death Ride in California has grades up to 12% with perhaps the inside of some turns steeper.

The killerest of killer hills in the bay area is Bohlman on Orbit and the steepest section is 22% but the average grade is 9%.

The upshot of this is that you absolutely cannot depend on some meter on a bicycle to measure grades. It just ain't possible. You have to stop, get off and use a long beam gradiometer.

Machka 

What he is doing to arrive at the 39% grade is to look at the bar on the right side of the graph. I have no idea what that bar is doing there because it has no relation to the rest of the information on the graph, and it doesn't show up on any other elevation chart I've ever seen. It should be ignored.


To correctly read the information on the chart you have to look at the GREEN line - ignore the black earthquake line (I'm not sure what that is - heart rate maybe?).

See the attached drawing. To find grade you need to follow these steps:

1) locate your lowest point (indicated by the arrow at the bottom of the drawing) and your highest point (indicated by the arrow at the top of the drawing).

2) figure out what the elevation of the lowest point is (I've drawn a red horizontal line from the lowest point, so that's easy to see), and figure out what the elevation of the highest point is (again, I've drawn a red horizontal line from the highest point, so that's easy to see). In this case, the lowest point is about 900 ft, and the highest point is about 2200 ft.

3) figure out at what distance on the graph you arrived at the lowest point (the vertical arrow indicating the lowest point can help you see approx. what the distance is) and figure out at what distance on the graphy you arrived at the highest point (the verticle line coming down from the highest point can help you see that). In this case, the lowest point was reached about 2.5 miles, and the highest point was reached about 7.5 miles.

4) subtract the lowest point from the highest point. In this case 2200 - 900 = 1300 ft.

5) subtract the higher distance from the lower distance. In this case 7.5 - 2.5 = 5 miles

And then continue with the formula I mentioned in one of my earlier posts --- If you convert 1300ft into miles, that's 0.246 miles. Then divide 0.246 miles by the 5 mile distance covered ==> 0.246/5 = 0.0492 = ~5%.

And that's how to calculate % grade from one of those elevation charts. It works the same way for all of them.

Machka 

Did you read one of my previous posts:

If it were a 39% grade over approx. 5 miles that would be 5*.39 = 1.95 miles or an elevation gain of approx. 10,300 feet in 5 miles.

Think of it this way ... that's like climbing approx. 2 vertical miles over the space of 5 miles which can also be expressed as the fraction 2/5ths (rise over run) ... which is 40%.