# Climbing on 10% gradient for 15 km...



## bianchi77 (Jul 15, 2008)

Sometimes, when I'm climbing in 10% to 15% gradient, how much power do I need for 12 km/h ? How can I maintain / train my breath ?
I lose my breath if it's long long long climb ...

Anyone has same experience with me...how to overcome that ?


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## bas (Jul 30, 2004)

bianchi77 said:


> Sometimes, when I'm climbing in 10% to 15% gradient, how much power do I need for 12 km/h ? How can I maintain / train my breath ?
> I lose my breath if it's long long long climb ...
> 
> Anyone has same experience with me...how to overcome that ?


practice? lower gearing?

what gearing you using??


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## sometimerider (Sep 21, 2007)

bianchi77 said:


> Sometimes, when I'm climbing in 10% to 15% gradient, how much power do I need for 12 km/h ? How can I maintain / train my breath ?
> I lose my breath if it's long long long climb ...
> 
> Anyone has same experience with me...how to overcome that ?


If you can climb even a 10k 10% hill at 10 km/hr, you're a much stronger rider than me. In other words, you should expect to be exhausted by trying what you suggest.

(There are various formulas that show what your vertical climbing rate should be (on steep hills) for a given aerobic capacity. Maybe you can find them.)


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## 99trek5200 (Jan 26, 2007)

Power required depends on your weight. Using one calculator for a 10% grade you would need between 300-360 watts depending if your weight is between 150 and 200 lbs to maintain 12 kph. Those numbers become 450-575 watts at 12kph if the grade becomes 15%.

Those are pretty high sustained watts. I think that kind of effort makes the best of riders hurt.


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## 99trek5200 (Jan 26, 2007)

sometimerider said:


> If you can climb even a 10k 10% hill at 10 km/hr, you're a much stronger rider than me. In other words, you should expect to be exhausted by trying what you suggest.
> 
> (There are various formulas that show what your vertical climbing rate should be (on steep hills) for a given aerobic capacity. Maybe you can find them.)


+1. That climb would have me puking a lung by 3k's.


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## bianchi77 (Jul 15, 2008)

bas said:


> practice? lower gearing?
> 
> what gearing you using??


Yes practicing

Gear 39-23

What do you thing of it ?


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## bianchi77 (Jul 15, 2008)

sometimerider said:


> If you can climb even a 10k 10% hill at 10 km/hr, you're a much stronger rider than me. In other words, you should expect to be exhausted by trying what you suggest.
> 
> (There are various formulas that show what your vertical climbing rate should be (on steep hills) for a given aerobic capacity. Maybe you can find them.)


Where can I find the formula ?
Or what kind of tool that I can use ? How much ?


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## bianchi77 (Jul 15, 2008)

99trek5200 said:


> Power required depends on your weight. Using one calculator for a 10% grade you would need between 300-360 watts depending if your weight is between 150 and 200 lbs to maintain 12 kph. Those numbers become 450-575 watts at 12kph if the grade becomes 15%.
> 
> Those are pretty high sustained watts. I think that kind of effort makes the best of riders hurt.


I'm 61 kg my bike is around 7-8 kg..


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## wim (Feb 28, 2005)

bianchi77 said:


> Where can I find the formula ?


This "Dr. Lim" formula seems to work pretty well:

bike + rider weight (in kg) x 9.8 x elevation gain (in meters)
_divided by_
time (in seconds) = power (in watts).
add 10% for rolling- and air resistance to fine-tune the watt number.


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## Guest (Jul 31, 2008)

It is very unlikely you are going to find a road with 10 or 12 % grades for any sustained length of time, certainly not for 10 or 12 KM.

While it is probable there are places where the road will pitch up to 10 or 12 % over its length, it is not likely to maintain that for more than a few yards at a time.


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## barry1021 (Nov 27, 2005)

If you are climbing a 10-15% gradient in a 39-23, there is nothing wrong with your breathing. You are a world class cycler. Mt Washington averages 12% for 7.6 miles and I doubt anyone does it in a 39-23. 

b21


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## cpark (Oct 13, 2004)

barry1021 said:


> If you are climbing a 10-15% gradient in a 39-23, there is nothing wrong with your breathing. You are a world class cycler. Mt Washington averages 12% for 7.6 miles and I doubt anyone does it in a 39-23.
> 
> b21


+1.
Lower gearing might help.
Maybe 39-25 or 27?


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## Blue CheeseHead (Jul 14, 2008)

bianchi77 said:


> Where can I find the formula ?
> Or what kind of tool that I can use ? How much ?


Here is a link to a calculator for you:

http://bikecalculator.com/veloUS.html


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## ilan (Nov 27, 2006)

toomanybikes said:


> It is very unlikely you are going to find a road with 10 or 12 % grades for any sustained length of time, certainly not for 10 or 12 KM.
> 
> While it is probable there are places where the road will pitch up to 10 or 12 % over its length, it is not likely to maintain that for more than a few yards at a time.


There is the Mont du Chat starting from Le Bourget du Lac (near Aix-les-Bains), France 13.5km for 1264m, for 9.4% average. There has been a race there in early July for the last 7 years, course record 48:30. The race is open to all, no license required. Most of the profile is given here: http://www.climbbybike.com/climb.asp?Col=Le-Mont-du-Chat&qryMountainID=6925 I don't think it's ever been used in the Tour de France, I don't know about other professional races. 

-ilan


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## ilan (Nov 27, 2006)

cpark said:


> +1.
> Lower gearing might help.
> Maybe 39-25 or 27?


More like 34x27 which is about 70 rpm for 11kph. 

-ilan


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## Groove1797 (Jul 28, 2008)

Ventilation is not a limiting factor in output so your breath is the last thing to worry about. Even at your highest (max) workload you will still be exhaling o2. To increase a sustainable workload you must increase your lactate threshold (t-vent) by training by using interval and tempo workouts


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## iliveonnitro (Feb 19, 2006)

barry1021 said:


> If you are climbing a 10-15% gradient in a 39-23, there is nothing wrong with your breathing. You are a world class cycler. Mt Washington averages 12% for 7.6 miles and I doubt anyone does it in a 39-23.
> 
> b21


Not true. Many people can do much harder, it's just that cadence suffers. I've done 16% grade (spikes to 24%) for ~2mi on 39x25. A 39x23 is only a difference of 2rpm. 36 vs 34rpm.

It sucks a lot, but it's not impossible. A friend did it in his 42x25. 12% actually doesn't sound that bad after that.


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## ilan (Nov 27, 2006)

iliveonnitro said:


> Not true. Many people can do much harder, it's just that cadence suffers. I've done 16% grade (spikes to 24%) for ~2mi on 39x25. A 39x23 is only a difference of 2rpm. 36 vs 34rpm.
> 
> It sucks a lot, but it's not impossible. A friend did it in his 42x25. 12% actually doesn't sound that bad after that.


Gino Bartali won the 1938 Tour de France riding up the Tourmalet (a dirt road at the time) in a 46x19 (approximately 39x17). Those were the days....

-ilan


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## sometimerider (Sep 21, 2007)

bianchi77 said:


> I'm 61 kg my bike is around 7-8 kg..


Lightweight, huh? Ok, per the bikecalculator site, for you to do 12 km/hr up a 15 km 15% grade would require 380 watts for 73 minutes. World class.

To do 10 km/hr on a 10 km 10% grade requires 212 watts for an hour. Doesn't sound like much, but I couldn't do it. (I would require 270 watts, since I weigh more.)

View attachment 134464


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## cityeast (Sep 16, 2004)

toomanybikes said:


> It is very unlikely you are going to find a road with 10 or 12 % grades for any sustained length of time, certainly not for 10 or 12 KM.
> 
> While it is probable there are places where the road will pitch up to 10 or 12 % over its length, it is not likely to maintain that for more than a few yards at a time.


Come and visit the Alps buddy. France, Switzerland, Italy and Austria all have a few mountain passes that would easily fit this criteria. Try THIS RIDE in Italian-speaking Switzerland...averages 9.7% over 15km.


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## bianchi77 (Jul 15, 2008)

sometimerider said:


> Lightweight, huh? Ok, per the bikecalculator site, for you to do 12 km/hr up a 15 km 15% grade would require 380 watts for 73 minutes. World class.
> 
> To do 10 km/hr on a 10 km 10% grade requires 212 watts for an hour. Doesn't sound like much, but I couldn't do it. (I would require 270 watts, since I weigh more.)
> 
> View attachment 134464


Thanks for the info...
It's very usefull, I guess it can be used as a reference on the trainer bike...
but I don't have a heavy trainer that able to simulate a climbing road...
and precisely know how much power do I dissipate....


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## gatorling (Jun 25, 2008)

wim said:


> This "Dr. Lim" formula seems to work pretty well:
> 
> bike + rider weight (in kg) x 9.8 x elevation gain (in meters)
> _divided by_
> ...


Dude..that's not Dr. Lim's formula..

That's the formula for potential energy..then you divide it by change in time to get power.

P=F*h
F = Force in Newtons, F = m*a, a = 9.8m/s^2, m = total weight of you and your bike in kg

7-10% for rolling /air resistance sounds about right since you won't be traveling at high speeds so air resistance won't be huge but I'm guessing you're going to be losing a significant amount of energy in frame flex.


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## tom_h (May 6, 2008)

Concerning the estimation of human power output from hill climbing data, and specifically "_add 10% for rolling- and air resistance to fine-tune the watt number_" , I am wondering if the +10% value is perhaps _too_ conservative.

From the tire rolling resistance data at http://www.biketechreview.com/tires/AFM_tire_crr.htm , 
a typical Michelin Pro3 Race tire consumes about _15 watts per wheel_. 
That's on a smooth roller at 25 MPH.

Furthermore, they claim "_Crr on typical road surfaces may be 50 to 100 % higher_". 
Let's say 50% more, on a typ asphalt road. 
That's 44 watts for 2 tires - a _lot_ of rolling resistance! (at 25 mph).

Power consumption due to tires likely depends on speed in some way -- but I don't know the details. For car tires, at least, the roll resistance Crr seems fairly constant out to about 50 mph (ref: http://www.greenhybrid.com/discuss/f22/tire-rolling-resistance-16474 )

44 watts per 2 tires is about 10% of a competitive racer's output (~ 400 W ?), but it's closer to 20% for a fit recreational cyclist (~200 W ?). 

Does this seem reasonable ??​


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## Doctor Who (Feb 22, 2005)

bianchi77 said:


> Thanks for the info...
> It's very usefull, I guess it can be used as a reference on the trainer bike...
> but I don't have a heavy trainer that able to simulate a climbing road...
> and precisely know how much power do I dissipate....



If you want to know how much power you're generating, you need to get a powermeter. I think we went over this in some other thread. These calculators are good for making rough estimates, but they're kinda worthless.


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## bianchi77 (Jul 15, 2008)

about the interval and tempo workouts...is there any methods or ways that work effectively and efficiently in a short time ? I don't have plenty of time for it


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## Doctor Who (Feb 22, 2005)

bianchi77 said:


> about the interval and tempo workouts...is there any methods or ways that work effectively and efficiently in a short time ? I don't have plenty of time for it


Google Tabata Protocol. Not really climbing-specific, but if you're pressed for time, well, no better way of going about it.


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