Best Rate of Climb
bernithebiker
Posts: 4,148
Whilst climbing the other day, my mind was drifting off (again) and I wondered what grade of slope would give the best rate of climb (i.e. the most metres up per second).
Intuition would say the steepest climb would be the winner, but I'm not so sure, as there comes a point where you tend to bog down on slopes >10%.
I seem to go best on slopes of about 4 to 5%, i.e. the easier gradient is compensated for by a proportionally higher speed, and therefore a higher vertical m/s.
Am I talking gibberish?
Intuition would say the steepest climb would be the winner, but I'm not so sure, as there comes a point where you tend to bog down on slopes >10%.
I seem to go best on slopes of about 4 to 5%, i.e. the easier gradient is compensated for by a proportionally higher speed, and therefore a higher vertical m/s.
Am I talking gibberish?
0
Comments
-
IME is around 7%.
For long climbs (over 20 minutes) I always got my best VAM on climbs that were 7% average... that said, most alpine climbs are around that figure, so that might be a coincidence.left the forum March 20230 -
I'd guess 6-7%.
Sounds like a question that cyclist magazine would try to answer.0 -
I have a lot of stats in Veloviewer. (14,000 segment attempts)
I sorted every segment I have ever ridden by VAM, and filtered out any climb less than 5 minutes.
My top 15 were all between 6 and 8%, with the average just under 7.5%0 -
Whilst climbing the other day, my mind was drifting off (again) and I wondered what grade of slope would give the best rate of climb (i.e. the most metres up per second).
The one where you put out the most w/kg.0 -
Whilst climbing the other day, my mind was drifting off (again) and I wondered what grade of slope would give the best rate of climb (i.e. the most metres up per second).
The one where you put out the most w/kg.
Well let's assume that's constant shall we?0 -
Whilst climbing the other day, my mind was drifting off (again) and I wondered what grade of slope would give the best rate of climb (i.e. the most metres up per second).
The one where you put out the most w/kg.
Well let's assume that's constant shall we?
Not sure what you mean by 'constant' - it's going to vary between individuals. You need an actual number, and the number matters, as it will be part of the equation.0 -
Whilst climbing the other day, my mind was drifting off (again) and I wondered what grade of slope would give the best rate of climb (i.e. the most metres up per second).
The one where you put out the most w/kg.
Well let's assume that's constant shall we?
Not sure what you mean by 'constant' - it's going to vary between individuals. You need an actual number, and the number matters, as it will be part of the equation.
I fear you are stating the 'bleeding obvious'!
Of course it would vary. But for simplicity, and the purpose of this exercise, we need to assume it's constant.
i.e. lets assume my best 5min power is 300W, what gradient of slope gets me the best rate of climb?0 -
Good luck with that...0
-
Whilst climbing the other day, my mind was drifting off (again) and I wondered what grade of slope would give the best rate of climb (i.e. the most metres up per second).
The one where you put out the most w/kg.
Well let's assume that's constant shall we?
Not sure what you mean by 'constant' - it's going to vary between individuals. You need an actual number, and the number matters, as it will be part of the equation.
I fear you are stating the 'bleeding obvious'!
Of course it would vary. But for simplicity, and the purpose of this exercise, we need to assume it's constant.
i.e. lets assume my best 5min power is 300W, what gradient of slope gets me the best rate of climb?
depends how heavy you are and the gearing.
If you have a mass of say 70kg the bike 10kg thats 80kg.
Multiply by gravity (9.81) and you have a total weight of 785N.
Power/Force = Velocity
so 300/785 = 0.35m/s of vertical ascent.
the angle of the slope you can go up will be dependant upon the gearing, itself dependant upon the cadance you want to ride at.0 -
I have a lot of stats in Veloviewer. (14,000 segment attempts)
I sorted every segment I have ever ridden by VAM, and filtered out any climb less than 5 minutes.
My top 15 were all between 6 and 8%, with the average just under 7.5%
I just did the same, similar number of segments at 15000.
Again, filtered out anything less than 5 minutes, because there's some silly VAMs on those!
Interestingly, the average gradient on my top 15 was 8.9%.
Got me wondering, as I guess different types of riders may have quite different results. Skinny little runts like myself, probably do get our highest VAMs on the steeper stuff compared to a larger, powerful rider who can still nail it on a shallower slope?
Anyway, fascinating stuff!0 -
Whilst climbing the other day, my mind was drifting off (again) and I wondered what grade of slope would give the best rate of climb (i.e. the most metres up per second).
The one where you put out the most w/kg.
Well let's assume that's constant shall we?
Not sure what you mean by 'constant' - it's going to vary between individuals. You need an actual number, and the number matters, as it will be part of the equation.
I fear you are stating the 'bleeding obvious'!
Of course it would vary. But for simplicity, and the purpose of this exercise, we need to assume it's constant.
i.e. lets assume my best 5min power is 300W, what gradient of slope gets me the best rate of climb?
depends how heavy you are and the gearing.
If you have a mass of say 70kg the bike 10kg thats 80kg.
Multiply by gravity (9.81) and you have a total weight of 785N.
Power/Force = Velocity
so 300/785 = 0.35m/s of vertical ascent.
the angle of the slope you can go up will be dependant upon the gearing, itself dependant upon the cadance you want to ride at.
In terms of energy the best slope is the steepest, as more of your watts are going in to overcoming gravity, and less in to wind resistance.
However, in practice a few interesting things happen as you go steeper;
1) You run out of gears and have to ride a cadence which is too low.
2) If you put on easier gears you can go steeper, but at some point balance becomes an issue (no going fast enough to balance side to side).
3) If your balance is very good, you may keep the bike upright but loose grip.
4) If the surface is grippy enough eventually the front wheel will lift the steeper you go.
Somewhere in the above the lack of inertia start effecting your pedal stroke and muscle recruitment. The slower you go, the less inertia you have to carry you through dead spots (no matter how fast your cadence). This requires using less efficient muscles. (A similar effect can be seen on low inertia trainers where people report lower power outputs). It seems to vary person to person though.
The above means that you'll climb quicker the steeper it is, given you can balance, have a smooth pedal stroke and low enough gearing. Obviously w/kg is a big factor in how well cyclists climb, however the above skills go some way to differentiate which cyclist prefer which gradients.
In practice most people find 7-10%.0 -
Good luck with that...
Everyone else seems to get it, not sure why you don't?0 -
Good luck with that...
Everyone else seems to get it, not sure why you don't?
I get that you will not be able to come up with one, single, universally-meaningful answer. Anyway, you already answered the question in your first post (the 'talking gibberish' bit).0 -
the angle of the slope you can go up will be dependant upon the gearing, itself dependant upon the cadance you want to ride at.
Which itself is going to be dependent on the power you can sustain0 -
the angle of the slope you can go up will be dependant upon the gearing, itself dependant upon the cadance you want to ride at.
Which itself is going to be dependent on the power you can sustain
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.0 -
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.0
-
the angle of the slope you can go up will be dependant upon the gearing, itself dependant upon the cadance you want to ride at.
Which itself is going to be dependent on the power you can sustain
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.
News just in: riding up a hill is all about w/kg, in case you missed it. So you've chosen a constant power. Now choose a constant gear and a constant weight. Otherwise, you might just as well make up a number. Which is probably what you'll end up doing anyway...0 -
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.
Of course different riders will produce different powers. What I'm interested in, is if I assume MY performance to be a constant, what % gives best rate of climb.
As someone has already suggested, gearing must play a part, as there will come a point where cadence will drop too much, and it will become harder to maintain the required 'fixed' power. (Power = Force x cadence).
So maybe the answer is; as steep as possible, but within the limits of your gearing.
Interesting that some have suggested 7% as being their optimum; does this mean their gearing is too high beyond this?0 -
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.
The steeper you climb, the slower you go, hence the least air resistance you need to fight. So in theory, the steeper, the better.
The problem is that the bicycle is not designed to have an infinite number of gear ratios, the position on the bike means that above a certain gradient you might have to spend energy keeping the front wheel on the road, low speed means wobble as well, you might have loss of traction at the rear etc. There are many factors that contribute.
I find climbing at ca. 7% gives me the best results: speed drops below 10mph, air resistance becomes negligible, yet I am still riding in a comfortable position, I have good gears, which means I can keep a healthy cadence and I have no problem to control the front wheel.left the forum March 20230 -
Yes - in theory, you want to be putting as much energy as possible in gaining elevation (potential energy) - you'd probably climb a ladder with your bike on your back the fastest. As I think Ugo is saying, all the slope does is accommodate the limited gears and traction/balance.ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0
-
the angle of the slope you can go up will be dependant upon the gearing, itself dependant upon the cadance you want to ride at.
Which itself is going to be dependent on the power you can sustain
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.
News just in: riding up a hill is all about w/kg, in case you missed it. So you've chosen a constant power. Now choose a constant gear and a constant weight. Otherwise, you might just as well make up a number. Which is probably what you'll end up doing anyway...
It's not hard to work out that if I can make 400W I'm going to go up hills faster than if I make 300W.
Froome goes up hills faster than me, and I go up hills faster than a granny (hopefully).
I'm surprised you keep banging on about this, because I' think everyone 'gets' that.
So using words of one syllable where possible;
Day 1. I go up a 2km hill of 3%
Day 2. I go up a 2km hill of 6%
Day 3. I go up a 2km hill of 9%
Ok here's the hard part for you; assume that on each day I'm keeping my power meter to PRECISELY 250W, unless external factors dictate that I can't.
Which day gives the best rate of climb? Presumably day 3.
But assuming 'normal' gearing of something like 36-25, I suspect that on Day 3 cadence may drop enough to mean that I can no longer achieve 250W......0 -
Darkhairedlord wrote:depends how heavy you are and the gearing.
If you have a mass of say 70kg the bike 10kg thats 80kg.
Multiply by gravity (9.81) and you have a total weight of 785N.
Power/Force = Velocity
so 300/785 = 0.35m/s of vertical ascent.
OK, I'm rubbish at maths, so bear with me if this is a daft question :
Don't you have to know the angle/gradient at which you're headed skywards before you can calculate metres per second of vertical ascent ?0 -
It's not hard to work out that if I can make 400W I'm going to go up hills faster than if I make 300W.
Froome goes up hills faster than me, and I go up hills faster than a granny (hopefully).
I'm surprised you keep banging on about this, because I' think everyone 'gets' that.
So using words of one syllable where possible;
Day 1. I go up a 2km hill of 3%
Day 2. I go up a 2km hill of 6%
Day 3. I go up a 2km hill of 9%
Ok here's the hard part for you; assume that on each day I'm keeping my power meter to PRECISELY 250W, unless external factors dictate that I can't.
Which day gives the best rate of climb? Presumably day 3.
But assuming 'normal' gearing of something like 36-25, I suspect that on Day 3 cadence may drop enough to mean that I can no longer achieve 250W......
Yep - that's nice and precise, isn't it. Don't forget to include things like fatigue and wind direction as well. Or alternatively, jut make up a number. Nobody will know. Not even you.0 -
Darkhairedlord wrote:depends how heavy you are and the gearing.
If you have a mass of say 70kg the bike 10kg thats 80kg.
Multiply by gravity (9.81) and you have a total weight of 785N.
Power/Force = Velocity
so 300/785 = 0.35m/s of vertical ascent.
OK, I'm rubbish at maths, so bear with me if this is a daft question :
Don't you have to know the angle/gradient at which you're headed skywards before you can calculate metres per second of vertical ascent ?
No, within reason it is irrelevant. Meaning it doesn't work if you have a gradient of 0.1% or so, as the speed you can reach at that gradient is dominated by air resistance rather than gravity. Above 6-7% air resistance is almost irrelevant, hence it's all gravityleft the forum March 20230 -
the angle of the slope you can go up will be dependant upon the gearing, itself dependant upon the cadance you want to ride at.
Which itself is going to be dependent on the power you can sustain
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.
News just in: riding up a hill is all about w/kg, in case you missed it. So you've chosen a constant power. Now choose a constant gear and a constant weight. Otherwise, you might just as well make up a number. Which is probably what you'll end up doing anyway...
It's not hard to work out that if I can make 400W I'm going to go up hills faster than if I make 300W.
Froome goes up hills faster than me, and I go up hills faster than a granny (hopefully).
I'm surprised you keep banging on about this, because I' think everyone 'gets' that.
So using words of one syllable where possible;
Day 1. I go up a 2km hill of 3%
Day 2. I go up a 2km hill of 6%
Day 3. I go up a 2km hill of 9%
Ok here's the hard part for you; assume that on each day I'm keeping my power meter to PRECISELY 250W, unless external factors dictate that I can't.
Which day gives the best rate of climb? Presumably day 3.
But assuming 'normal' gearing of something like 36-25, I suspect that on Day 3 cadence may drop enough to mean that I can no longer achieve 250W......
but for the same vertical metres isn't it:
Day 1. I go up a 2km hill of 3%
Day 2. I go up a 1km hill of 6%
Day 3. I go up a 666m hill of 9%
so the relative speeds to be equal VM would be, say: 12, 6 and 4 mph. In that example I think the 9% would lead to the fastest rate of climb - quite out of saddle burst of less than half a mile.
I suggest the length of the hill, or magnitude of VM to be climbed is an important factor. A short hill of 9% sets a different challenge to a long one. Its the Alps vs UK question, short climbs, even if steep are different to long ones.
Otherwise Bernie has it, at constant power steeper means fewer watts for wind resistance therefore more for vertical metres.0 -
You're fixated on this; when testing for one variable you need to keep the others constant. So for argument's sake, we're keeping power constant. It's a hard concept to grasp I know, but do try.
Of course different riders will produce different powers. What I'm interested in, is if I assume MY performance to be a constant, what % gives best rate of climb.
As someone has already suggested, gearing must play a part, as there will come a point where cadence will drop too much, and it will become harder to maintain the required 'fixed' power. (Power = Force x cadence).
So maybe the answer is; as steep as possible, but within the limits of your gearing.
Interesting that some have suggested 7% as being their optimum; does this mean their gearing is too high beyond this?
Not only gearing, for some people, even if they increased their gearing the inertia would go so low that they wouldn't be able to get the same power out. Inertia isn't just about cadence, but the whole system.
One of the reasons pro's do 'speed work' behind a moped is to get used to high inertia pedal stroke. Similarly climbers will train on climbs to train for low inertia. Different riders, even with the same tested w/kg may find climbing on different gradients harder or easier depending on how well adapted their pedal stroke is.0 -
It's not hard to work out that if I can make 400W I'm going to go up hills faster than if I make 300W.
Froome goes up hills faster than me, and I go up hills faster than a granny (hopefully).
I'm surprised you keep banging on about this, because I' think everyone 'gets' that.
So using words of one syllable where possible;
Day 1. I go up a 2km hill of 3%
Day 2. I go up a 2km hill of 6%
Day 3. I go up a 2km hill of 9%
Ok here's the hard part for you; assume that on each day I'm keeping my power meter to PRECISELY 250W, unless external factors dictate that I can't.
Which day gives the best rate of climb? Presumably day 3.
But assuming 'normal' gearing of something like 36-25, I suspect that on Day 3 cadence may drop enough to mean that I can no longer achieve 250W......
Yep - that's nice and precise, isn't it. Don't forget to include things like fatigue and wind direction as well. Or alternatively, jut make up a number. Nobody will know. Not even you.
Your cynicism knows no bounds!
Is it so hard for you to consider a control situation where fatigue and wind are not factors?
Anyway, no thanks to you, I think we've arrived at an answer, which is;
As steep as possible, as long as you have sufficiently low gearing to be able to maintain your 'standard' power.
This confirms my belief that in hilly sportives like the Etape, many riders are not using low enough gears and getting bogged down as a result.0 -
But... It's not just about gearing.... Even if you have infinite gears your inertia will drop. Some people just get get out the power with low inertia and so will get a better power output and VAM on shallower gradients.
But yes, probably a lot of people are fundamentally over geared too. But just increasing gears and cadence isn't always the answer.
Edit to insert link http://cyclingtips.com/2013/09/climbing-and-time-trialling-how-power-outputs-are-affected/0 -
Your cynicism knows no bounds!
Is it so hard for you to consider a control situation where fatigue and wind are not factors?
Thanks for the compliment. No, it's not hard to consider - just pointless, that's all.0 -
Your cynicism knows no bounds!
Is it so hard for you to consider a control situation where fatigue and wind are not factors?
Thanks for the compliment. No, it's not hard to consider - just pointless, that's all.
Fine, move along then.0