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Random Friday Question (Climbing)

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  • #32
    Inquitus
    Registered Users, Registered Users 2 Posts: 13,778 ✭✭✭✭Inquitus


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

    Now thats just crazy talk :)


  • #33
    Raam
    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.


  • #34
    smacl
    Moderators, Society & Culture Moderators Posts: 15,962 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.


  • #35
    Keep_Her_Lit
    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.


  • #36
    Keep_Her_Lit
    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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  • #37
    ROK ON
    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.


  • #38
    Inquitus
    Registered Users, Registered Users 2 Posts: 13,778 ✭✭✭✭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.


  • #39
    smacl
    Moderators, Society & Culture Moderators Posts: 15,962 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 ;)


  • #40
    smacl
    Moderators, Society & Culture Moderators Posts: 15,962 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.


  • #41
    ROK ON
    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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  • #42
    smacl
    Moderators, Society & Culture Moderators Posts: 15,962 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.


  • #43
    bad2dabone
    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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