# Percent Grade %



## shanabit (Jul 16, 2007)

Simple question here. 

When someone says its a 15% grade hill, what are they actually saying?

Im guessing rise over run, simple slope if you will but the percent NEVER makes any sense to me. Should I just get one of those gizmos that tell me the percent Im on as far as the climb goes??

All hills SUCK for me since Im a clyde anyways:cryin: 

Thanks

Shane


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## tuffguy1500 (Jul 17, 2008)

The gradient is the tangent of the angle of inclination times 100. In other words, get a gizmo that tells you . I use the Polar CS600.


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## Ibashii (Oct 23, 2002)

shanabit said:


> Simple question here.
> 
> When someone says its a 15% grade hill, what are they actually saying?
> 
> [...]


They're saying either a) they have a really, really easy gear or b) they like to exaggerate.

Sections of 15% and more certainly exist--often at the turning points of switchbacks and in other geologically difficult spots--but there aren't too many bike-able roads with sustained sections of 15%. Just for a reference, the sharpest grade on the climb up Alpe d'Huez is 12%, during a hairpin towards the bottom of the climb.

But to answer your specific question, tuffguy is right: this isn't math you can do in your head. You need either a GPS or a computer with a pressure-based altimeter if you really want to know.


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## pagey (Oct 30, 2009)

get off road and you will find plenty of gradient like that. Of cause you also have the gearing to get over it


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## Ibashii (Oct 23, 2002)

pagey said:


> get off road and you will find plenty of gradient like that. Of cause you also have the gearing to get over it


Right, sorry I wasn't more specific: I'm always amazed at what some MTBers are willing to climb. Then again, this is *road*bikereview.com, right?

I was thinking about this thread today while climbing a stretch of 10% grade (about 3 km). It was hard, so much harder than the 5-8% grades I'd been climbing all day. The organizers of a local cyclosportif that takes place in two weeks thought it would be amusing to add it to the end of the race this year, so I thought I'd better check it out beforehand. I hate them for ruining an otherwise extremely difficult race that is now uber-difficult.


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## Hank Stamper (Sep 9, 2009)

shanabit said:


> Should I just get one of those gizmos that tell me the percent Im on as far as the climb goes??


If you want to be 'that guy' who tells everyone the grades you climb you'll probably need one. Otherwise I don't know what purpose being able to assign a number to a hill serves. It's pretty easy to tell the difference between easy and torture without a gizmo.


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## JCavilia (Sep 12, 2005)

Ibashii said:


> They're saying either a) they have a really, really easy gear or b) they like to exaggerate.
> 
> Sections of 15% and more certainly exist--often at the turning points of switchbacks and in other geologically difficult spots--but there aren't too many bike-able roads with sustained sections of 15%. *Just for a reference, the sharpest grade on the climb up Alpe d'Huez is 12%, during a hairpin towards the bottom of the climb.*
> 
> But to answer your specific question, tuffguy is right: this isn't math you can do in your head. You need either a GPS or a computer with a pressure-based altimeter if you really want to know.


For another reference, the steepest climb that's been used more than once in a grand tour is probably the Alto del Angliru, used a few times in the Vuelta a Espana. It's about 12 kilometers long in total, but the first half is relatively easy. Here's a description of the last half from the Wikipedia article:


> From six kilometres to the summit, it averages 13.1%. The steepest part, the Cueña les Cabres at 23.6%, is 3 km (1.9 mi) from the summit. There are two later ramps at 18% to 21% (sources vary).


There aren't many paved public roads that steep anywhere. I have a few local climbs here in central Connecticut with sustained stretches (a mile or so) of over 10%, and a couple of short bits well over 15%. They are real grinders for me, standing in a 39x25 and barely moving fast enough to stay upright -- roughly 4.5 mph at under 40 rpm.

You can make a pretty good estimate from a topo map. Nobody needs to know precise numbers anyway, except for bragging purposes.


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## MattGent (May 22, 2009)

tuffguy1500 said:


> The gradient is the tangent of the angle of inclination times 100. In other words, get a gizmo that tells you . I use the Polar CS600.


Which is the same as rise / run, as the OP stated.


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## Ibashii (Oct 23, 2002)

JCavilia said:


> For another reference, the steepest climb that's been used more than once in a grand tour is probably the Alto del Angliru, used a few times in the Vuelta a Espana. It's about 12 kilometers long in total, but the first half is relatively easy. Here's a description of the last half from the Wikipedia article:


Duuuuude...that's horrible. Absolutely horrible. I guess a pro should be able to put up with anything for 6km, but still.

There is a cyclosportif every year in France (I think it's in the Pyrenees but I'm not sure) whose name is something like "ascent into hell" or "death mountain" or some such ominous nonsense: it advertises several 20% grades and long stretches of 15%+. 

The reason I don't know more about it is that I will never, ever even think about doing it. I love climbing, but c'mon already.

I wonder if PhilippeC knows the one I mean, or has even perhaps done it??


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## spade2you (May 12, 2009)

Hank Stamper said:


> If you want to be 'that guy' who tells everyone the grades you climb you'll probably need one. Otherwise I don't know what purpose being able to assign a number to a hill serves. It's pretty easy to tell the difference between easy and torture without a gizmo.


Pretty much. I know there are people out there who know the % grade on the really painful climbs, so I just ask them from time to time. I really don't feel like spending $ to tell me why this climb is harder.


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## JCavilia (Sep 12, 2005)

Ibashii said:


> Duuuuude...that's horrible. Absolutely horrible. I guess a pro should be able to put up with anything for 6km, but still.
> 
> There is a cyclosportif every year in France (I think it's in the Pyrenees but I'm not sure) whose name is something like "ascent into hell" or "death mountain" or some such ominous nonsense: it advertises several 20% grades and long stretches of 15%+.
> 
> ...


I don't believe you. If you really loved climbing you'd never call that "horrible." You'd say scary, awesome, wouldn't want to do it every day, but for the challenge, once . . .

Going up mountains is one of the core aspects of road cycling. Why the hell all those gears, anyway? I mean, wouldn't you like to do Mt. Washington just once?


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## Gnarly 928 (Nov 19, 2005)

*Knowing the gradient is useful...*

If you've not ridden the climb but you know the gradient, you can select the proper gearing before hand. Having the proper cassette can save your knees and your ego sometimes. 

Now-a-days with all the computer sites (Map My Ride, Garmin Share, etc etc) without much trouble you can see what almost every road's gradients are before you go there and you can pre-select the proper gearing..

Or, you can just 'always' ride a triple or a compact with a big rear cog (super low) and make do with fewer usable 'mid-range' gearing, but it doesn't make much sense having a 34/27 gear combo if you only have to ride a 5% climb for a few miles. On the other hand, if you are riding something like this little "Gem" 
http://www.everestchallenge.com/page1.ihtml?id=19&parent_id=0

You might be inclined to desire a mountain-bike rear derailuer with a huge gear AND a triple for that last climb on Sunday, with 28,000+ miles of climbing already into your legs.


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## BryanSayer (Sep 22, 2009)

spade2you said:


> Pretty much. I know there are people out there who know the % grade on the really painful climbs, so I just ask them from time to time. I really don't feel like spending $ to tell me why this climb is harder.


Sometimes people don't know what they are talking about though.

Grade, as defined by road building people, is simply rise over run, like you learned in middle school. So a 45 degree climb (if such existed) would be a 100% grade, and would rise 100' for every 100' of run.

There are some shorter climbs (1/2 mile or less) that can be in the 16-17-18 % range here in Central Ohio, but road engineers have standards that they won't allow roads to exceed in general. The surfaces don't behave well above certain points.

If you know a transportation or civil engineer, you might discuss the issue with them.

Otherwise, I would say something like Delorme's Topo-USA map or one of the online topographic maps.


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## Ibashii (Oct 23, 2002)

JCavilia said:


> I don't believe you. If you really loved climbing you'd never call that "horrible." You'd say scary, awesome, wouldn't want to do it every day, but for the challenge, once . . .
> 
> Going up mountains is one of the core aspects of road cycling. Why the hell all those gears, anyway? I mean, wouldn't you like to do Mt. Washington just once?


Hmmmm...if you only saw my ride log. Where I live going up mountains is the ONLY aspect of cycling that anybody cares about, and over the years that's rubbed off on me. 

I guess you're right to some extent though, because I know this much: with my current set-up I wouldn't last more than a few hundred meters at 20%+, and I'm not about to put a triple or some monstrous cassette on my bike just to wobble up the steepest mountain road in the country one time. So let me rephrase: I love climbing, except in events where people have openly searched for the most manly-man challenge available, at the expense of all racing logic.

Ahhh feck, maybe I'm just getting old. Like, if I was in a trench war right now and my commanding officer tried to get me all psyched up to go take a different trench from the enemy, I'd be all, "naa, seriously, why? Some of us are probably gonna get killed, and even if we take the trench, so what? They're probably gonna take it back tomorrow or next week anyway. Let's stay here and play Scrabble instead."


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## shanabit (Jul 16, 2007)

Hank Stamper said:


> If you want to be 'that guy' who tells everyone the grades you climb you'll probably need one. Otherwise I don't know what purpose being able to assign a number to a hill serves. It's pretty easy to tell the difference between easy and torture without a gizmo.



LOL, yeah I know but I was talking to some dude and he was yapping about grades of this and that on certain rides and my response was, " What the heck are you talking about??
We live in southeastern OHIO and Im 260lbs on a road bike. Every hill sucks to me:thumbsup: They ALL SUCK!!!  

Id like to start my own bike club called the Climbing Clydes. You are of course required to meet the minimum weight of 225 LOL

Thanks gents


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## spade2you (May 12, 2009)

shanabit said:


> LOL, yeah I know but I was talking to some dude and he was yapping about grades of this and that on certain rides and my response was, " What the heck are you talking about??
> We live in southeastern OHIO and Im 260lbs on a road bike. Every hill sucks to me:thumbsup: They ALL SUCK!!!
> 
> Id like to start my own bike club called the Climbing Clydes. You are of course required to meet the minimum weight of 225 LOL
> ...


Get stronger and lighter, either that or get a Garmin so you can avoid certain areas.


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## tpgrole (Aug 20, 2009)

Ibashii said:


> They're saying either a) they have a really, really easy gear or b) they like to exaggerate.


or c) they ride in Pittsburgh a lot.

A couple of weeks ago I was riding around exploring Pittsburgh and rode up (very slowly) 2 of the "Dirty Dozen" by accident. I wasn't really sure where I was going, just riding around and looking to get some exercise. I got my workout that day for sure. 

I'll guess that it's been posted on here before but if you haven't seen it, there are some good videos on YouTube of the Dirty Dozen ride.

http://bike-pgh.org/2010/02/video-p...-race-to-become-a-global-ride-training-video/


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## Ibashii (Oct 23, 2002)

tpgrole said:


> or c) they ride in Pittsburgh a lot.
> 
> A couple of weeks ago I was riding around exploring Pittsburgh and rode up (very slowly) 2 of the "Dirty Dozen" by accident. I wasn't really sure where I was going, just riding around and looking to get some exercise. I got my workout that day for sure.
> 
> ...


LOL, that's awesome: It was a while ago, but I did three years in Pittsburgh and climbed all of those streets (some of the lesser grades regularly) except Canton, which I once looked at in amazement but chose not to attempt (it really looks like a brick wall!). I loved city riding in the 'Burgh, really an unrecognized treasure of urban cycling. What I hated there was having beer bottles thrown at me while riding in the beautiful PA countryside, which could be a cycling paradise if they got rid of the ********.

Anyway, I was referring to sustained periods of 15% or more; as steep (and poorly-maintained) as Pittsburgh's hills are, they're all SHORT!! A strong rider or someone reasonably fit with a triple can get out of the saddle, huff and puff and stomp their way up: you only need to go about 6 kmh to stay upright. It hurts terribly, but you can almost always see the top: 10k of 7% is a thousand times harder than 800 meters at 20%+.


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## Blue CheeseHead (Jul 14, 2008)

Ibashii said:


> 10k of 7% is a thousand times harder than 800 meters at 20%+.


For me, I would disagree. I am about to go to California and will encounter both scenarios. 

At 195# the 10k at 7% will take about a 250 watt effort for an hour for me to get over. For the long climb it is a mind set that you can get in and just grind. Now 800 meters at 20% will take about 400 watts for 7 minutes (4.5 mph). 7 minutes at that power hurts an old guy like me, a lot! Last year I stalled. When I looked back I saw my friends serpentining up the hill (an important tip I shall use this year)


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## Ibashii (Oct 23, 2002)

Blue CheeseHead said:


> For me, I would disagree. I am about to go to California and will encounter both scenarios.
> 
> At 195# the 10k at 7% will take about a 250 watt effort for an hour for me to get over. For the long climb it is a mind set that you can get in and just grind. Now 800 meters at 20% will take about 400 watts for 7 minutes (4.5 mph). 7 minutes at that power hurts an old guy like me, a lot! Last year I stalled. When I looked back I saw my friends serpentining up the hill (an important tip I shall use this year)


Wow, you actually put numbers on it, you win...I was just going on the impression that getting into that climbing mode is somehow more meditative and noble than going anaerobically nuts for a few minutes, but I guess that's subjective. 

I respect distance runners more than sprinters too, big surprise.


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## JCavilia (Sep 12, 2005)

> 10k of 7% is a thousand times harder than 800 meters at 20%+.





> For me, I would disagree. I am about to go to California and will encounter both scenarios.
> For the long climb it is a mind set that you can get in and just grind.





Ibashii said:


> Wow, you actually put numbers on it, you win...I was just going on the impression that getting into that climbing mode is somehow more meditative and noble than going anaerobically nuts for a few minutes, but I guess that's subjective


I think you still win, Ibashii. Short steeps and looooong climbs are both hard, in different ways, but a really long grade is a special (though pleasureable) challenge, at least for somebody like me who doesn't get to do them too often.

I've done the only (AFAIK) actual 10,000 foot continuous climb in the world, Mt. Haleakala on Maui. It averages only about 5%, and is rarely steeper than 6%, except for a short stretch near the top. I climb short 5% grades around here in the big ring. On Haleakala I was very grateful my rented bike had a triple, and I spent a lot of time in that granny gear.


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## bahueh (May 11, 2004)

*teammate of mine..*



JCavilia said:


> For another reference, the steepest climb that's been used more than once in a grand tour is probably the Alto del Angliru, used a few times in the Vuelta a Espana. It's about 12 kilometers long in total, but the first half is relatively easy. Here's a description of the last half from the Wikipedia article:
> 
> 
> There aren't many paved public roads that steep anywhere. I have a few local climbs here in central Connecticut with sustained stretches (a mile or so) of over 10%, and a couple of short bits well over 15%. They are real grinders for me, standing in a 39x25 and barely moving fast enough to stay upright -- roughly 4.5 mph at under 40 rpm.
> ...


climbed that last year...he's a strong climber and the pictures of him at the top were telling..he looked completed wasted. hardest thing he's ever done apparently...


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## dekindy (Jul 7, 2006)

Get an inexpensive Sky Mounti inclinometer. 

http://www.velimpex.com/inclinometer.htm


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## MoreBoostPlease (Jul 27, 2010)

wow.
http://en.wikipedia.org/wiki/Canton_Avenue


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## Ibashii (Oct 23, 2002)

MoreBoostPlease said:


> wow.
> http://en.wikipedia.org/wiki/Canton_Avenue


Wow indeed...you managed the rare newb double-whammy of both dredging up a months-old thread _and_ linking to something already covered in said thread, just a handful of posts above you. Nice work.

(it is a b!tch of a hill though, isn't it)


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## MoreBoostPlease (Jul 27, 2010)

Ibashii said:


> Wow indeed...you managed the rare newb double-whammy of both dredging up a months-old thread _and_ linking to something already covered in said thread, just a handful of posts above you. Nice work.
> 
> (it is a b!tch of a hill though, isn't it)


I do what I can...:thumbsup: 

I didn't realize I was still looking through threads from a search, thought I was back to newest threads. And, FWIW, the road was mentioned but the page I listed was not linked to in this thread. rrr:


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## superg (May 9, 2010)

To answer the OP question, when someone is talking about a 15% climb they are talking about a road that rises 15m for every 100m of horizontal distance.


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## alexb618 (Aug 24, 2006)

superg said:


> To answer the OP question, when someone is talking about a 15% climb they are talking about a road that rises 15m for every 100m of horizontal distance.


2nded

this is the correct way to measure gradient

can do this over smaller distances to get more accurate numbers

eg if you hold a 1m spirit straight on the road and there is a 15cm gap at one end between the road and the spirit level, then you have a 15% gradient on that 1 metre section


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