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Random Friday Question (Climbing)

  • 20-04-2012 1:05pm
    #1
    Registered Users, Registered Users 2 Posts: 2,807 ✭✭✭


    Had this in my head the other day and was wondering if there's a known answer. For the sake of this questuion ignore the type of surface and the weather conditions etc. Assume a normal day, dry road etc and also assuming a standing start.

    Is there an "ideal" incline to climb say 100m as quickly as possible? I hope the question is easy to understand. i.e. would it be quicker to climb at a painful 20% angle for the 100m (short distance slowly) or would a very light slope be much much quicker to do (longer distance quickly)? I realise this is starting to sound like a Top Gear race or something like that....

    The follow-on question then would be as to whether the "ideal" slope would change based on how much you want to climb.


Comments

  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    I would guess gearing, weight, and fitness are variables you couldn't ignore in this question, so there isn't a single good answer. Basically it's going to come down to effort over time, e.g. less effort over a longer time or more effort over a shorter one. Sounds like a job for power meter guy.

    Actually thinking about it, I'd be much more fearful of the short ramps like the wall than the longer drags like shay elliot. Must try to drop a couple of pounds more before the Orwell gig.


  • Registered Users, Registered Users 2 Posts: 2,807 ✭✭✭g0g


    smacl wrote: »
    I would guess gearing, weight, and fitness are variables you couldn't ignore in this question, so there isn't a single good answer. Basically it's going to come down to effort over time, e.g. less effort over a longer time or more effort over a shorter one. Sounds like a job for power meter guy.

    Actually thinking about it, I'd be much more fearful of the short ramps like the wall than the longer drags like shay elliot. Must try to drop a couple of pounds more before the Orwell gig.
    Yeah I realise there's fitness too, so maybe assume equal level of fitness between the two cyclists, one of who is good at flat sprints and one who flies up hills.


  • Registered Users, Registered Users 2 Posts: 582 ✭✭✭Dr.Millah


    I would imagine it would depend on a persons style, a serious masher might have a better time on the big incline as cadence would likely be low.

    You may also get the benefit of going mad for the first 50 meters before your HR climbs up and you start puffing air. If you get that far you only have another 50m to go so you could slog it out at close to max output.


  • Registered Users, Registered Users 2 Posts: 11,505 ✭✭✭✭DirkVoodoo


    Are you looking at this from an energy consumption point of view, i.e. is there a set amount of energy "available" to each cyclist in these scenarios, and which would be the "easiest" way to burn that up?


  • Registered Users, Registered Users 2 Posts: 470 ✭✭Zen0


    The ideal distance is the one which uses the least energy. That is a vertical climb. Unfortunately most of us don't have the power output to achieve this (escape velocity). Possibly Ryan Sherlock does, judging by his Strava results.


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  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    I think the slope you pick is going to be based on what part of your climbing you want to improve. For short steep slopes, you're going to be expending much more energy for a shorter duration, so that's what you practice. For long climbs, you'll expend more energy overall but over a longer duration.

    Given a choice of two hills on your route, if you get into the habit of choosing the one you find more difficult, it ought to become easier quite quickly. Note that I don't practice what I preach here. I still tend to take Cruagh - Johnnie Foxes as my lunch time spin, whereas up and down Kilmashougue could be better use of my time. The devils elbow as a last kicker after a long spin is another great one to test the mental and physical endurance.


  • Registered Users, Registered Users 2 Posts: 2,807 ✭✭✭g0g


    Thanks for the thoughts. I'm just taking it on a simple level. If I said I want to set the world record for time taken from standing still to reach a point 100m while cycling a bike on a road, is there an ideal slope for that road?

    This might be answering my own question, but does Strava have a stat showing minutes per vertical metre against climbs? That would give me my answer right away surely! (although I'd have to compare 100m climbs)


  • Registered Users, Registered Users 2 Posts: 2,807 ✭✭✭g0g


    smacl wrote: »
    I think the slope you pick is going to be based on what part of your climbing you want to improve. For short steep slopes, you're going to be expending much more energy for a shorter duration, so that's what you practice. For long climbs, you'll expend more energy overall but over a longer duration.

    Given a choice of two hills on your route, if you get into the habit of choosing the one you find more difficult, it ought to become easier quite quickly. Note that I don't practice what I preach here. I still tend to take Cruagh - Johnnie Foxes as my lunch time spin, whereas up and down Kilmashougue could be better use of my time. The devils elbow as a last kicker after a long spin is another great one to test the mental and physical endurance.
    Thanks for the thoughts although FYI it's nothig to do with (lack of!) climbing skills. I'm just wondering which would be faster time-wise.


  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    g0g wrote: »
    Thanks for the thoughts although FYI it's nothig to do with (lack of!) climbing skills. I'm just wondering which would be faster time-wise.

    For faster, I'd guess its more about putting out very large amounts of energy in a short time, which suggests repeats on very steep slopes. Shallower gradients and/or slower speeds for long periods will build endurance rather than strength.


  • Registered Users, Registered Users 2 Posts: 781 ✭✭✭Mr. Grieves


    g0g wrote: »
    This might be answering my own question, but does Strava have a stat showing minutes per vertical metre against climbs? That would give me my answer right away surely! (although I'd have to compare 100m climbs)

    Yes, look at the VAM for the same person for different climbs. Per Strava:

    "VAM measures your Vertical Ascent in Meters/hour – it measures how quickly you are traveling upward. VAM is useful for comparing your effort on different hills and segments, and is used by both cyclists and runners. To get a high VAM score, grades between 6-10% generally present the best opportunity to ascend quickly, as they are steep enough to avoid wind, and gradual enough to allow unrestricted motion."


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  • Registered Users, Registered Users 2 Posts: 3,795 ✭✭✭C3PO


    Is Lumen away? I'd have expected a detailed answer and technical diagram by now!


  • Closed Accounts Posts: 6,831 ✭✭✭ROK ON


    g0g wrote: »
    Thanks for the thoughts. I'm just taking it on a simple level. If I said I want to set the world record for time taken from standing still to reach a point 100m while cycling a bike on a road, is there an ideal slope for that road?

    This might be answering my own question, but does Strava have a stat showing minutes per vertical metre against climbs? That would give me my answer right away surely! (although I'd have to compare 100m climbs)

    As previous poster mentioned VAM is the unit of measurement. One proviso - I have found that it is only really useful on like for like measurement.

    My VAM on long shallow climbs is about 23% below my VAM for steep climbs. Why, I think on very steep climbs there is a minimum speed necessary to simply stay upright - thus I push very hard to simply stay upright. On shallow climbs this doesnt isnt such a factor.

    So I think that may get to your answer, in that I would cover 100m of ascent on a steep climb faster than I would for a shallow climb.
    Because of that, I only ever compare my VAM on the same climb - I dont compare my VAM on one climb to another. According to wiki, a 1% point increase in gradient increases VAM by 50m.
    http://en.wikipedia.org/wiki/Velocity_Ascended,_Metres_per_hour


  • Registered Users, Registered Users 2 Posts: 31,222 ✭✭✭✭Lumen


    ROK ON wrote: »
    My VAM on long shallow climbs is about 23% below my VAM for steep climbs. Why, I think on very steep climbs there is a minimum speed necessary to simply stay upright - thus I push very hard to simply stay upright. On shallow climbs this doesnt isnt such a factor.

    Air resistance is greater on shallow climbs.


  • Registered Users, Registered Users 2 Posts: 31,222 ✭✭✭✭Lumen


    The solution for ultimate VAM is to connect your cranks to a vertical pulley system, Tarzan-style.

    Although I think it was Cheetah who pulled Tarzan up to his treehouse, and I don't know much about bikefit for chimpanzees, they presumably need a very compact frameset. Anyway, I'm not sure why he was called Cheetah, I think he fought off a cheetah or something.


  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    Lumen wrote: »
    Air resistance is greater on shallow climbs.

    You're also expending time and effort travelling the horizontal component of the journey, unless of course you're taking the Tarzan route again. Also, Cheetah is cheating, as he's using his arms as well as legs for the ascent, and his bike weighs a very tidy 0g. If you're only considering the upward vertical component, bikes are probably a sub-optimal mode of transport, coming back down on the other hand...


  • Registered Users, Registered Users 2 Posts: 2,991 ✭✭✭el tel


    I would say yes there is an ideal gradient for a particular individual to make 100 vertical ascent in minimum time. The only sane way to find it would be empirically. Like on a variable incline treadmill timed over the distance per particular degree/min/sec of gradient. By the time youd tried all the inclines youd be so much fitter that you were t the start the earlier results would be superseded. or maybe not.

    If you know how quickly you can ride the following distances at the following constant gradients, then you will be able to close in on the answer :)

    Distance (m) Gradient (Deg)

    5729.87 1
    2865.37 2
    1910.73 3
    1433.56 4
    1147.37 5
    956.68 6
    820.55 7
    718.53 8
    639.25 9
    575.88 10
    524.08 11
    480.97 12
    444.54 13
    413.36 14
    386.37 15
    362.80 16
    342.03 17
    323.61 18
    307.16 19
    292.38 20
    279.04 21
    266.95 22
    255.93 23
    245.86 24
    236.62 25
    228.12 26
    220.27 27
    213.01 28
    206.27 29

    Getting into SpiderPig territory…

    200.00 30
    194.16 31
    188.71 32
    183.61 33
    178.83 34
    174.34 35
    170.13 36
    166.16 37
    162.43 38
    158.90 39
    155.57 40
    152.43 41
    149.45 42
    146.63 43
    143.96 44
    141.42 45
    139.02 46
    136.73 47
    134.56 48
    132.50 49
    130.54 50
    128.68 51
    126.90 52
    125.21 53
    123.61 54
    122.08 55
    120.62 56
    119.24 57
    117.92 58
    116.66 59
    115.47 60
    114.34 61
    113.26 62
    112.23 63
    111.26 64
    110.34 65
    109.46 66
    108.64 67
    107.85 68
    107.11 69
    106.42 70
    105.76 71
    105.15 72
    104.57 73
    104.03 74
    103.53 75
    103.06 76
    102.63 77
    102.23 78
    101.87 79
    101.54 80
    101.25 81
    100.98 82
    100.75 83
    100.55 84
    100.38 85
    100.24 86
    100.14 87
    100.06 88
    100.02 89
    100.00 90


  • Closed Accounts Posts: 172 ✭✭Rofo


    I'm not touching this one. As far as I know, gravity doesn't exist on flat roads :D


  • Registered Users, Registered Users 2 Posts: 227 ✭✭sled driver


    Rofo wrote: »
    I'm not touching this one. As far as I know, gravity doesn't exist on flat roads :D

    Ya, gravity sucks, man !!! ;)


  • Administrators, Social & Fun Moderators, Sports Moderators Posts: 78,393 Admin ✭✭✭✭✭Beasty


    You can play about with the bike calculator, if you put out, say, 300w over a 100m climb

    5% slope (2km distance) - 5.84mins

    10% (1km) - 4.91mins

    20% (500m) - 4.66mins(the improvement at higher gradients tails off rapidly beyond 20%)

    Now that assumes you can put out the same power on the same slope. I personally find it easier to put out higher power on steeper slopes (when I am out of the saddle), which suggests steeper but shorter is "easiest". That makes sense if you think about it. If the slope was 1% you would need to travel 10km to ascend 100m. To do that in 5 minutes would need a speed of 120kph. Clearly the air resistance would prevent anything approaching such a speed


  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    el tel wrote: »

    Distance (m) Gradient (Deg)

    100.00 90

    [Pedantic b'stard mode]The horizontal distance at 90 degrees is 0m. 100m horizontal to 100m vertical is a gradient of 1:1 or 45%.[/Pedantic b'stard mode]


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  • Registered Users, Registered Users 2 Posts: 2,991 ✭✭✭el tel


    smacl wrote: »
    [Pedantic b'stard mode]The horizontal distance at 90 degrees is 0m. 100m horizontal to 100m vertical is a gradient of 1:1 or 45%.[/Pedantic b'stard mode]

    You are not wrong but the distances listed are not horizontal distances. They are distance to travel.


  • Closed Accounts Posts: 172 ✭✭Rofo


    g0g wrote: »
    Had this in my head the other day and was wondering if there's a known answer. For the sake of this questuion ignore the type of surface and the weather conditions etc. Assume a normal day, dry road etc and also assuming a standing start.

    Is there an "ideal" incline to climb say 100m as quickly as possible? I hope the question is easy to understand. i.e. would it be quicker to climb at a painful 20% angle for the 100m (short distance slowly) or would a very light slope be much much quicker to do (longer distance quickly)? I realise this is starting to sound like a Top Gear race or something like that....

    The follow-on question then would be as to whether the "ideal" slope would change based on how much you want to climb.

    Having just watched yesterday's Giro del Tretino mountain-finish stage with a couple of beers, I've arrived at what is definitely the right the answer to this: It all depends on two things - your power:weight ratio and overall weight.

    Leaving aside the minimal increases in rolling resistance and inertial resistance that a heavier rider is subject to for a moment - let's imagine two riders. One with slightly better power:weight ratio, the other being 10kg lighter. Set them off and point the road up by a degree every 100m, the rider with better power:weight ratio will do better at first but at some tipping point that I haven't a clue how to work out, it will become tougher for the heavier stronger rider as the incline becomes steeper and the lighter rider will do better. (I'm thinking of how Jose Rujano and Pozzavivo took over yesterday when they hit 20 degree stuff)

    ...or maybe that's b0llock5 :-). Maybe it's not realistic to think of humans in physics terms and there are other variables that come into play that have a greater effect: The psychological effect of seeing a ridiculous 'wall' ahead of you; the almost panic effect that a sustained output of near peak power has on your body; or just imagining that the smaller climber has the advantage.


  • Registered Users, Registered Users 2 Posts: 725 ✭✭✭Keep_Her_Lit


    All other things being equal, the rider with the better power to weight ratio will climb faster. The whole point of this metric is that it normalises power output with respect to weight. In other words, it isn't absolute (or overall) weight that matters but the number of Watts available to propel each kg of weight. Ultimately it does come down to physics.

    Moreover, the steeper the gradient, the better the measured performance will correlate to the power to weight ratio.

    The situation you describe would be atypical, I think, i.e. where the heavier rider has the superior power to weight ratio. The reason the best climbers have the classical "mountain goat" physiques is because that's the make up which delivers the highest power to weight ratio. All muscle and sinew, no fat and proportionately large heart and lungs.

    The same applies in other sports. Look at the weights that Olympic Weightlifters shift in the lower weight classes. As a proportion of body weight, they are significantly greater than those achieved by the heavyweights. That is, the lighter the class, the higher the power to weight ratio.

    This seems to hold true throughout the animal kingdom. A chimpanzee is a much more accomplished gymnast than a silverback gorilla, even though the latter has a much greater maximum power output. The ant dwarfs both of them and is enormously powerful for its size.

    I want to emphasize here that I am not in any way attempting to equate good climbers with either chimpanzees or ants.


  • Closed Accounts Posts: 172 ✭✭Rofo


    All other things being equal, the rider with the better power to weight ratio will climb faster. The whole point of this metric is that it normalises power output with respect to weight. In other words, it isn't absolute (or overall) weight that matters but the number of Watts available to propel each kg of weight. Ultimately it does come down to physics.

    Moreover, the steeper the gradient, the better the measured performance will correlate to the power to weight ratio.

    The situation you describe would be atypical, I think, i.e. where the heavier rider has the superior power to weight ratio. The reason the best climbers have the classical "mountain goat" physiques is because that's the make up which delivers the highest power to weight ratio. All muscle and sinew, no fat and proportionately large heart and lungs.

    The same applies in other sports. Look at the weights that Olympic Weightlifters shift in the lower weight classes. As a proportion of body weight, they are significantly greater than those achieved by the heavyweights. That is, the lighter the class, the higher the power to weight ratio.

    This seems to hold true throughout the animal kingdom. A chimpanzee is a much more accomplished gymnast than a silverback gorilla, even though the latter has a much greater maximum power output. The ant dwarfs both of them and is enormously powerful for its size.

    Ok I can follow you on the theory of 'power:weight ratio normalises power output with respect to weight' thing. Here's where I lose it: Why don't those same little guys do as well on the flat?

    What are we missing here? There must be other factors that we are leaving out! Does it eventually matter that the 'power' factor of a heavier rider with the same power:weight ratio as a lighter rider does actually require more power, hence they require more fuel that their systems find more challenging to consume, process and/or deliver?

    Don't forget the little guy's bike weighs the same as the big guy's - they're not in proportion! Advantage big guys surely!!

    What is it about going uphill that hands the advantage to the little guy with good power:weight ratio?


  • Registered Users, Registered Users 2 Posts: 725 ✭✭✭Keep_Her_Lit


    On the flat, at a steady racing speed, nearly all of the power dissipated is being used to overcome aerodynamic drag. That is, wind resistance is the dominant factor, while the influence of gravity is negligble (not zero, since rolling resistance increases with weight).

    So it could be crudely stated that on the flat, what matters is not the power to weight ratio but the power to frontal area ratio*. And this is where the advantage goes to the larger riders. The reason? The volume of a rider's body scales with his/her weight. But the frontal area doesn't.

    Take the example of a 60kg rider vs. a 90kg rider. Assuming a body density of 1kg/litre (the same as water), the volumes of their bodies will be 60 and 90 litres respectively. That is, if they each do the Eureka trick and jump into a bath brimful of water, one will displace 60 litres of water and the other will displace 90 litres.

    For simplicity, let's use the formulae for the volume of a sphere and the area of a circle to compare the change in volume with the change in frontal area. If the 90kg rider is squashed into a 90 litre sphere, he will have a radius of 27.8cm and a frontal area of 2,428cm2. Likewise, if the 60kg rider is squashed into a 60 litre sphere, he will have a radius of 24.3cm and a frontal area of 1,853cm2.

    Now look at the ratios of the frontal areas: 2,428cm2/1,853cm2 = 1.31

    So, we can conclude that if our competitive cyclists are sphere shaped, a 50% increase in rider weight will result in a 31% increase in frontal area. More generally, if the weight is scaled by X (X = 1.5 in this example), the frontal area is scaled by X^(2/3) [X raised to the power of 2/3]

    Fair enough, not many competitive cyclists are sphere shaped. However, the general principle will still hold and it is left as an exercise to the reader to establish realistic figures for human body shapes.

    Now let's rig the example with some carefully selected power to weight ratios which ensure that the heavier rider turns out to be faster on the flat but slower on the climbs biggrin.gif

    OK, we're going to choose 20 minute power to weight ratios of 6.0W/kg for the mountain maestro and 5.5W/kg for the sprint star. So the whippet can hold 360W for 20 minutes, while the beefcake can belt out 495W over the same interval.

    These power to weight ratios immediately suggest that the lighter guy is going to be quicker on the climbs. But, as you correctly pointed out, we don't know for sure unless we also factor in the weight of the bike. And since the bike weight is a larger proportion of the lighter rider's body weight, this adjustment should nudge the figures back in the favour of the heavier rider. Let's allow 8kg for bike plus clothing/shoes/helmet. In that case, we end up with 5.29W/kg for the lighter rider + bike and 5.05W/kg for the heavier rider + bike. The lighter rider still has a clear advantage and will climb faster.

    On the flat, again assuming that we have sphere shaped riders, we have the following power to frontal area ratios:

    90 kg rider : 495/0.2428 = 2,039W/m2
    60 kg rider : 360/0.1853 = 1,942W/m2

    In this case, the heavier rider has a clear advantage. The bike weight is irrelevant at a steady speed.

    So there you have it. The lighter rider, with the slightly higher power to weight ratio, is faster on the climbs but slower on the flat.

    Right, I'm away out for a spin.

    [* Of course, for a given frontal area, the aerodynamic drag can vary a lot. But we're assuming here that riders are using very similar equipment and that their riding positions are similarly aerodynamically efficient]


  • Closed Accounts Posts: 172 ✭✭Rofo


    Blimey! Thanks, that all makes sense :-)


  • Registered Users, Registered Users 2 Posts: 1,140 ✭✭✭snailsong


    I suspect the the optimal path on which to ascend the 100m will not be a straight line, but some sort of curve. In the initial phase the rider will have to accelerate so it may be even more efficient to begin on a slight downslope rapidly curving upwards and becoming a straight line once terminal velocity is achieved. Interestingly a family of curves called cycloids often crop up in this sort of problem.

    I hope this clarifies and simplifies the matter.:)


  • Registered Users, Registered Users 2 Posts: 31,222 ✭✭✭✭Lumen


    @Keep_Her_Lit your analysis is interesting but you can't diet yourself aero.

    I would interpret your results as "short/aero people need significantly less power to sustain the same speed on the flat".


  • Registered Users, Registered Users 2 Posts: 13,763 ✭✭✭✭Inquitus


    Howth Village side versus Sutton side is a good testbed for this. I think I am about 2 mins quicker up the village side from memory.


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  • Closed Accounts Posts: 6,831 ✭✭✭ROK ON


    To add a practical dimension to this, would people prefer to climb a 20km climb averaging 5% (with a very low StdDev), or an 8km climb at 12.5% gradient.


  • Registered Users, Registered Users 2 Posts: 13,763 ✭✭✭✭Inquitus


    ROK ON wrote: »
    or an 8km climb at 12.5% gradient.

    Now thats just crazy talk :)


  • Registered Users, Registered Users 2 Posts: 14,318 ✭✭✭✭Raam


    ROK ON wrote: »
    To add a practical dimension to this, would people prefer to climb a 20km climb averaging 5% (with a very low StdDev), or an 8km climb at 12.5% gradient.

    That's like choosing between a chocolate and fudge based desert or a chocolate and toffee based desert.


  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    ROK ON wrote: »
    To add a practical dimension to this, would people prefer to climb a 20km climb averaging 5% (with a very low StdDev), or an 8km climb at 12.5% gradient.

    As neither exist in Ireland and I've not cycled abroad, difficult to say. Both involve 1k of elevation gain, but taking the likes of the sally gap from sea level would only give you 500m, and there's no road over Carrauntoohil (1039m) as yet. Personally, I think I'd find the 20k at 5% easier, as the nearest for climbing I've done in a day is the WW200, which was difficult more because of the weather than the climbing. If and when cyclesuperstore decide to extend their free track pump at cafes scheme to free defibrillators on mountain tops, I'd rather see one's at the top of the wall and the devils elbow rather than slieve mann or shay elliot.


  • Registered Users, Registered Users 2 Posts: 725 ✭✭✭Keep_Her_Lit


    Lumen wrote: »
    @Keep_Her_Lit your analysis is interesting but you can't diet yourself aero.
    I'm not really sure what you mean by this, so I'll waffle a bit more and you can let me know whether or not I'm addressing your point.

    If you achieve a sufficiently large weight reduction through dieting, then you would indeed become more aero. A reduction in the girth of your torso and limbs would produce a smaller frontal area and less aerodynamic drag, thereby allowing the same speed to be sustained for less power. For a large weight loss, your form would also become more efficient - less power would be wasted by the movement of leaner legs and upper body. The improvement in performance would of course be even more pronounced for climbing, assuming only a change in weight and not power output, i.e. if the weight loss is all fat and no muscle.

    However, the 90kg vs 60kg comparison doesn't really make sense for a pre-diet vs post-diet situation, as applied to an individual rider. If an individual sheds a lot of surplus weight, then they are going to be faster everywhere, whether climbing or on the flat.

    Instead, the comparison is more valid for two riders of widely differing stature, both of whom are in peak athletic shape. A 90kg rider could never manage 5.5W/kg if lots of those kg were surplus to requirements. So we're talking about two lean athletes, one of whom is much taller, has broader shoulders, a wider torso and longer, bulkier limbs.

    Consequently, the 90kg rider will inevitably present a larger frontal area to the airstream than that presented by the 60kg rider. But the additional power generated by the 90kg rider will more than compensate for the larger frontal area, allowing the larger rider to sustain a higher speed.

    This type of comparison will obviously break down at some point. Massive riders (120kg+, perhaps) just won't have the endurnace or economy of form to allow a meaningful comparison.
    I would interpret your results as "short/aero people need significantly less power to sustain the same speed on the flat".
    Yes, that's right, provided that by "short" we mean those with a smaller frontal area than "tall" people.


  • Registered Users, Registered Users 2 Posts: 725 ✭✭✭Keep_Her_Lit


    ROK ON wrote: »
    To add a practical dimension to this, would people prefer to climb a 20km climb averaging 5% (with a very low StdDev), or an 8km climb at 12.5% gradient.
    I'd rather tackle the 12.5% over 8km, provided I had suitable granny gearing. I don't think I'd survive it on a 34-27, which is currently the lowest gear on my road bike's compact set up.

    5% is still a proper climb (well, in my books anyway!) and dragging it out over 20km would be interminable - pure torture.


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  • Closed Accounts Posts: 6,831 ✭✭✭ROK ON


    I have done a few long climbs in France. 5-7% gradient. In my opinion as an overweight poor climber they are a mental challenge because of the length of them. It feels like they will never end. But the road surface and granny gearing mean that they are doable.


    Any very steep climbs that I have done are a physical as well as mental challenge. After a point the pain in my legs, lungs, chest, airways is screaming at me to stop. The challenge is to keep the bike upright.

    I reckon that for the same rider on the same bile there is a tipping point where the steeper gradient climb takes longer due to sheer difficulty exhausting the body.


  • Registered Users, Registered Users 2 Posts: 13,763 ✭✭✭✭Inquitus


    ROK ON wrote: »
    I have done a few long climbs in France. 5-7% gradient. In my opinion as an overweight poor climber they are a mental challenge because of the length of them. It feels like they will never end. But the road surface and granny gearing mean that they are doable.


    Any very steep climbs that I have done are a physical as well as mental challenge. After a point the pain in my legs, lungs, chest, airways is screaming at me to stop. The challenge is to keep the bike upright.

    I reckon that for the same rider on the same bile there is a tipping point where the steeper gradient climb takes longer due to sheer difficulty exhausting the body.

    If you had a suitable granny gear the steeper climb would likely always be quicker. However I fully agree with your point above, even on a compact I think my legs would give up well before 8km at 10% was up, and the necessary rests would probably mean the 20km climb would be quicker, however if we added a ridic granny gear then I think the 8km climb would be quicker.


  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    FWIW, the steepest section of the Orwell Randonee is the wall, which involves 73m climbing over 629 horizontally. This equates to just 11.6% average gradient, though the gradient is not even, hitting 20% at it's worst. See OS map and profile below.

    201603.jpg

    Kilmashogue lane from the roundabout is 267m of climbing over 2.6k or 10% average gradient. Again from OS mapping;

    201606.jpg

    So your 8k at 12% equates to 12.7 repeats of the wall without respite, or three times something steeper and longer than kilmashogue. I seriously need to be thinking about do many more hill repeats ;)


  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    Well count me out of the 8k at 12%. I just tried 3 reps of kilmashogue lane, needed a couple of stops on the second rep, and didn't finish the third. Did it on the old hybrid as the road bike is currently out of action, which while heavy at 13.5k has super low gearing 28/32, so probably easier on balance. You also get a recovery period on the descent, so even these hill reps don't equate to the 8k continuous steep climb.

    I think a HRM and knowing your zones would help this type of climbing, as once the heart rate goes into the red, the clock is ticking to the amount more you can do before stopping.


  • Closed Accounts Posts: 6,831 ✭✭✭ROK ON


    I have climbed a 5km climb in France at over 10%. It was gruelling, absolutely vomit inducing horror. Every fibre of my body was in absolute agony.

    In contrast, I cycled up the Tourmalet and Hautacam - yes they are tough,but if you are appropriately geared you can just keep going.
    My point was that for a given granny gear, there is a breaking point for the average rider whereby VAM starts deteriorating rapidly on the steep climb just to the sheer physicality of it. Have done a fair few steep 2-3km climbs, I think it must be in excess of that - so I am saying for me north of 5km.


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  • Moderators, Society & Culture Moderators Posts: 15,812 Mod ✭✭✭✭smacl


    Yeah, there's a point, where you move well out of your comfort zone in terms of effort, that keeping going just stops being an option. I also find unclipping on a steep gradient to be a bit of a bollix which doesn't help matters when that point is reached. I think I'll work a weekly hill repeat session into my schedule to see if things can be improved upon. 3-4 reps of kilmashogue without having to stop en-route would seem like a reasonable goal.


  • Registered Users, Registered Users 2 Posts: 6,333 ✭✭✭bad2dabone


    smacl wrote: »
    I think a HRM and knowing your zones would help this type of climbing, as once the heart rate goes into the red, the clock is ticking to the amount more you can do before stopping.

    That's what I reckon aswell, if you can manage your effort, keep the heart beat down, you can manage the climb. Of course there is the problem, some hills are such that your heart rate is gonna be heading into the red zone regardless :D


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