What Does 25% Grade Look Like?

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Originally Posted by CR400

Wow, that looks painful. The only blessing is that it is short compared to what it could be. Imagine trying to climb that beast for another 100ft. I don't think I would make it.

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True- it looks to be only about 5 or 6 cars lengths long. Plus- there's a running head start flat spot at the bottom! Where I live the bottom of the hill ends right on a highway in a "T"....so you just have to get spinning immediately from a stop. :eek:
We have a short hill on our usual routes that is about this steep as in the photo, but there is a bank of woods up the right side of the road, a deep wooded ravine on the other, crumbling asphalt with NO shoulder, no painted lines on the pavement, and a blind right angle turn right in the middle. It's pretty scary when you are halfway up your crawl and you hear a farm truck approaching from behind.... :eek: :(

this is a bad shot from the tour yesterday, but you see gerdeman cresting the hill and then it looks like just a huge dropoff, it was a magnificent shot! Attachment 3794

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Originally Posted by Mr. Silver

You might be surprised. This is near the Ohio River in our small suburb...Its about 320 feet from the stop sign to the top of the hill; my Garmon measured it at 25% grade - much to my surprise.

I have done it twice, but I'm using the first and second gear (on a triple). I tried to start it in 5th gear and couldn't get halfway...unable to shift down at such slow speed.

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I hate to burst your bubble, but this is not a 25% grade. :( There's pretty much no such thing as a paved 25% grade. Your Garmin was probably affected by all the trees. That hill looks like a 9 or 10, which is definitely killer.

I showed the picture to Dh, who is like King of the Hills and very familiar with grade percentages. He concurred that it was probably a 9 or so. We both have a Garmin and know how it can freak out and show strange numbers when you're surrounded by trees or other obstructions.

But good for you for doing it! Definitely not easy! :D

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Originally Posted by Jiffer

I hate to burst your bubble, but this is not a 25% grade. :( There's pretty much no such thing as a paved 25% grade. Your Garmin was probably affected by all the trees. That hill looks like a 9 or 10, which is definitely killer.

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I don't know anything about the accuracy of a Garmin, but yes Virgina paved roads up to and over 25% do exist....
Seriously, the record holder is 30 some percent (there was a recent discussion of this on another thread) San Francisco, Pittsburgh, Seattle, New Zealand all have their share of steepies. I would say that hill is probably steeper than 9 or 10 percent easily, but I can't look at it and tell the difference between 18% and 25%. Remember now that we're talking about percent grade, not degree of angle (I would expect the Garmin to be pretty acurate though.. at least better than Topo - which I have used, but its too easy to come off the actual road and get variations)

If you have a Garmin Forerunner, it relies on satellite info to calculate elevation and grade percentages. These are not accurate. I have done rides where the total elevation climbing was 4500 ft and my Garmin Forerunner has come up with almost twice that. If you have the Edge, it has an altimeter built in to it and may be more accurate for straight elevation numbers but again I'm not sure if it calculates grade based on rise over run or from satellite info.

Looks steep though and good on ya!

Pinkbike - isn't that shot amazing!?! When I saw it last night, I swear that my stomach turned at the thought of riding over that crest (even though it probably wasn't as crazy as it looks from that angle)!!


I agree that it's hard to tell from a picture, but that road/grade looks very, very similiar to one we ride. My Polar calculated the one I ride at 13% (using barometric pressure as the altimeter, not GPS). It's REALLY hard to ride if you happen to hit it in the wrong gear (speaking from experience!! :o ). Thank goodness the one I ride is also pretty short!

Hmmm. Wonder where my old pictures from Kvam i Gudbrandsdalen are. I'd have to digitize them, but I do have a shot or two of the old road heading up there. I remember when I bought my first car (an East German Trabant, 2-cylinder 2-stroke with a gravity fuel line) my friends up there told me I should have read the handbook first because a Trabant would not make it up their hill with its 30% grade on the zig below their zag. I thought I might have to do like my folks' painter friend did when he drove his Model A Ford up to his place on top of Sonoma Mountain -- drive it backwards do keep the fuel flowing to the motor. But I didn't have to do a 3-point turn on that narrow little road and back up. The 30% stretch must have been short enough that the fuel already in the motor lasted through it. Don't think my "fuel" would get me up that hill on a bike, though. I can hike it, but I'm sure I couldn't ride it.

True that they don't build road grades that steep now, but they used to build roads just up and over anything. We've got roads around here from early 1800s, long before we were a state. So the original roads might have just been paths, but now they are maintained roads.

Can't vouch for that hill, but I concur you can find roads that steep. They aren't common, but they exist.

You can't necessarily trust the instanteous readout on your GPS--consider if one reading was off by -30m and the next reading off by +30m. However, the average will be close. The Garmin software does pull out the outlyers and correct against topo data (if you send it up their website).

The organizer of one of my favorite charity rides likes to describe the SW corner of mystate as "a place where they'll hang asphalt off the side of a cliff and call it a road". I suspect that a lot of rural areas in the country that haven't seen a lot of citification are the same.

Kelownagirl posted this link a while back (found it through a search). I've found it helpful. Just plug in distance and gain and you get percent grade:

http://www.csgnetwork.com/inclinedeclinegradecalc.html

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Originally Posted by Jiffer

I hate to burst your bubble, but this is not a 25% grade. :( There's pretty much no such thing as a paved 25% grade.

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Bubble's not burst (or bursted;) ), but I do believe it's accurate, albeit not precise. As Lisa said, photo's are deceiving and this one is. In addition, consider this:

• 25% grade on a 320 ft diagonal run only requires about 60' or 70' of rise (since the paved diagonal run is the hypotenuse of a right triangle and therefore longer than the horizontal run); what you don't see in the picture are the two houses that provide a good perspective confirming this
• this street is two blocks off the center of a town that looks nearly the same as it did 150 years ago. It's a river town and pavement wasn't planned, it evolved. I think the reason it's one way going down is because of the noise caused by cars 'burning rubber' in trying to climb it.
• I can easily take a 10% grade in middle to top gears with no problem; I can't even stand and walk on this one with my cycling shoes on and can't even get started to climb in anything over 2nd easiest gear.

While I acknowledge the shortcomings of Garmon or anything other than a survey, I assure you that it's not a 9 or 10% grade...

The Garmin Edge uses GPS + a barometric altimeter to determine altitude so it is supposedly a lot more accurate than the Forerunner that just uses GPS. The Forerunner is very often *way* off. For example, I climbed a hill this morning that is marked as a 12% grade. The forerunner told me it was -- get this -- a 427% grade! Somehow I got up to 14,000 some feet in less than a mile...

Now that was a particularly egregious error but I do find that it regularly gives me readings of 18+% on a hill that I know to be 8% at its worst.

That said, it is a steep hill! The good thing about grades that steep is that it is difficult to make them *too* steep. (They never do seem so steep in the photos though, do they?)

Solobiker, I think I need to ride with you! I seem to run into steep grades anytime I head west! :eek:

Anne

Fun article.

http://www.bikereader.com/contributo...ley/hills.html

This morning teigyr and I were admiring the local toughie--what we refer to as Claimjumper Hill (at the bottom of Southcenter for the locals). It's a 21% grade.

I've ridden down it, and I've seen people ride up it. Slowly. Very slowly :p .

East Hill

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Originally Posted by East Hill

This morning teigyr and I were admiring the local toughie--what we refer to as Claimjumper Hill (at the bottom of Southcenter for the locals). It's a 21% grade.

I've ridden down it, and I've seen people ride up it. Slowly. Very slowly :p .

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I don't even like to drive up that hill.