
RoadBikeReview Member
Reputation:
Climbing on 10% gradient for 15 km...
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 ?

RoadBikeReview Member
Reputation:
Originally Posted by bianchi77
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??

sometimereader
Reputation:
Originally Posted by bianchi77
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.)
Hard work pays off in the future. Laziness pays off now.
 Steven Wright

Now with a 5900SL P1
Reputation:
Power required depends on your weight. Using one calculator for a 10% grade you would need between 300360 watts depending if your weight is between 150 and 200 lbs to maintain 12 kph. Those numbers become 450575 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.

Now with a 5900SL P1
Reputation:
Originally Posted by sometimerider
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.

RoadBikeReview Member
Reputation:
Originally Posted by bas
practice? lower gearing?
what gearing you using??
Yes practicing
Gear 3923
What do you thing of it ?

RoadBikeReview Member
Reputation:
Originally Posted by sometimerider
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 ?

RoadBikeReview Member
Reputation:
Originally Posted by 99trek5200
Power required depends on your weight. Using one calculator for a 10% grade you would need between 300360 watts depending if your weight is between 150 and 200 lbs to maintain 12 kph. Those numbers become 450575 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 78 kg..

Originally Posted by bianchi77
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 finetune the watt number.

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.

RoadBikeReview Member
Reputation:
If you are climbing a 1015% gradient in a 3923, 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 3923.
b21

Cpark
Reputation:
Originally Posted by barry1021
If you are climbing a 1015% gradient in a 3923, 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 3923.
b21
+1.
Lower gearing might help.
Maybe 3925 or 27?

Originally Posted by bianchi77
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

RoadBikeReview Member
Reputation:
Originally Posted by toomanybikes
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 AixlesBains), 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...ountainID=6925 I don't think it's ever been used in the Tour de France, I don't know about other professional races.
ilan
Last edited by ilan; 07312008 at 09:44 AM.

RoadBikeReview Member
Reputation:
Originally Posted by cpark
+1.
Lower gearing might help.
Maybe 3925 or 27?
More like 34x27 which is about 70 rpm for 11kph.
ilan

RoadBikeReview Member
Reputation:
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 (tvent) by training by using interval and tempo workouts

Impulse Athletic Coaching
Reputation:
Originally Posted by barry1021
If you are climbing a 1015% gradient in a 3923, 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 3923.
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.

RoadBikeReview Member
Reputation:
Originally Posted by iliveonnitro
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
Last edited by ilan; 07312008 at 02:52 PM.

sometimereader
Reputation:
Originally Posted by bianchi77
I'm 61 kg my bike is around 78 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.)
Hard work pays off in the future. Laziness pays off now.
 Steven Wright

Lurkaholic
Reputation:
Originally Posted by toomanybikes
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 Italianspeaking Switzerland...averages 9.7% over 15km.
"It takes two to lie, one to lie and one to listen" Homer J. Simpson

RoadBikeReview Member
Reputation:
Originally Posted by sometimerider
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.)
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....

RoadBikeReview Member
Reputation:
Originally Posted by wim
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 finetune the watt number.
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
710% 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.

Concerning the estimation of human power output from hill climbing data, and specifically "add 10% for rolling and air resistance to finetune 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/f...sistance16474 )
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 ??

Lexicon Devil
Reputation:
Originally Posted by bianchi77
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.

RoadBikeReview Member
Reputation:
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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