I'm not a climber or alpinist, but from several book accounts of Everest climbers I had a general gist that it's less about climbing and more about slowly (not) dying. Walking and climbing several steep kilometers while suffocating and freezing to death while simultaneously suffering from several high altitude illnesses (potentially deadly). So more accurate "challenge" would be riding an exercise bike outside in the middle of some winter cyclone for a few days, while wearing a mask restricting your airflow by a quarter and taking laxatives and psychotropic drugs.
As a cyclist, I can tell you that it's not about experiencing the challenge of climbing everest on a bike (and nobody who did it claims that). It is a challenge about gaining a very large number of vertical elevation on a single climb, which requires a combination of endurance, planning, practice and dedication.
Using the height of Mt. Everest is simply a good target because it is a very big challenge to climb 8848m and in addition combines this challenge with the most famous mountain on the planet. FWIW, there is also trenching, i.e. descending the depth of the Mariana Trench, ~11000m, on a single ride (which requires climbing the same amount; https://www.youtube.com/watch?v=dFQ5fVjQACc), and nobody claims that this is equivalent to diving down there.
and notably, if you actually climb mt everest, you start well above sea level so the total ascension is much less than 8848m. Clearly not a direct comparison
In case anyone wants the numbers, Everest base camp to the peak is 3485 vertical meters. But this is done over multiple days. From camp 4 to the peak is "just" 850 vertical meters, less than 1/10 of the 8848m Everesting climb.
My favorite quote from Reinhold Messner who soloed Everest, did it without supplemental O2, etc...
"When I rest I feel utterly lifeless except that my throat burns when I draw breath...I can scarcely go on. No despair, no happiness, no anxiety. I have not lost the mastery of my feelings, there are actually no more feelings. I consist only of will." - Messner on the first solo ascent of Everest
Outside of Everest itself, I'm not sure there is much that can compare except other climbs at similar altitudes.
Thinking about your comment seriously. I am typically all in my head and find myself looking for things to push me to those moments of focus. It’s why I originally found this quote when I was hiking a lot.
This biking challenge can be accomplished on a nearby hill any time of the year, no winter cyclone needed. Most people would be unable to achieve it (training is necessary).
that wouldn't even scratch the surface. ice climbing is always perilous and the mountain is a bigger foe than the altitude. as a mountaineer, every placement could be a fatal mistake, every piece of equipment a potential murder weapon, the layers of ice are constantly tricking you, the weather making its own decisions while the mountain avalanches and ice falls according to its own schedule. meanwhile you are logistically coordinating an impossible set of too many itineraries in many languages on a mostly linear track where simple queueing delay can be fatal for a myriad of reasons.
I still have the email that Andy van Bergen wrote to the Hells 500 group in 2013, suggesting that we turn George Mallory’s notoriously epic training regime into a permanent cycling challenge. I was up for the bike ride but quietly skeptical that it would become a lasting phenomenon. In Andy’s words:
> “This epic is tough - but it will form the springboard for a new wave of endurance riding around the globe.”
Still, as part of the launch of Everesting as a standing challenge, I cleared six solo, unsupported repeats of Australia’s Mt Hotham in February 2014.
Then I slept for a week.
Fast forward to today, and it’s evident that I was wrong and Andy was right. There are nearly twenty-three thousand Everestings documented in the official hall of fame, and no doubt more unrecognised besides. I guess it’s a combination of being just-about-achievable, with constraints that help focus the effort without compromising the difficulty, plus the enjoyable imagery associated with the branding.
Will I do it again? Probably not, but if you’re interested, then let it be known that no great athletic gifts are required, and with adequate preparation and mindset a very average cyclist (such as myself) can pull it off.
No "very average" cyclist can complete even one ascent of Mt Hotham, let alone 6.
Even whoever has last place on the Strava segment for any HC climb is well above the "average" cyclist, who will get off and walk for any gradient over about 7 or 8% (let alone The Meg, an infamous pinch early in the climb that reaches something like 17%).
I think this remark illuminates the psychological barrier that I’m alluding to. To be clear, I’m speaking of potential, not of the likely outcome if you took someone off the street today at the median ability of all current bicycle owners worldwide.
If someone is healthy and fit enough to ordinarily ride a bicycle, then with the right equipment and preparation they will almost certainly be able to ascend the likes of Mt Hotham, and with a lot more preparation they will probably be able to do it six times. If they really want to. Probably. I speak as living proof of that, because only a few years prior to doing so I weighed 120kg, smoked forty cigarettes a day, owned no bicycle at all, and had sat on my backside for years without any cardiovascular exercise.
At the time of writing, there’s only one other documented everesting of Hotham in the hall of fame, and frankly that surprises me.
I'll add myself as a second data point here. Lots of beer. Lots of cigarettes. Lots of sitting and programming.
Now most of my friends think I'm some kind of elite athlete and I am not, I just rode around on a bike every couple of days for several years. It is incredible what a change in lifestyle can do.
The average person can absolutely everest, or ride 100k, or whatever, given a bit of training. Of course, training for a year so you can ride your bike up and down a hill all day isn't that appealing to most folks. But it could still be done.
Both of you guys are relying one data point. If you look at the literature on exercise adaptation you actually find a incredibly large variance in the response.
There are a decent amount of people, who just don't adapt to exercise.
I don't generally understand these surveys. This one seems to indicate the term "non-responder" is not just unhelpful, but possibly damaging.
"Thus, just because an individual does not improve their VO2max or 1RM with training, this does not mean that they have not derived a multitude of other benefits from exercise, many of which, such as increased social interaction seen in community exercise settings"
What I don't see in this survey is anything related to "off the couch" improvements, which is clearly what we are talking about. Neither myself nor GP said we went from regionals to nationals. We went from cigarettes and beer to recreational riding. I have a hard time believing those gains aren't available to almost everyone. But, I didn't find a study so it doesn't exist :)
If you look at all the positive benefits of exercise you find very few people who don't get some positive benefit from exercise whether that's better insulin sensitivity, better vO2 max, better cholesterol, or weight loss.
But when you look at one specific benefit of exercise such as the endurance required to accomplish these feats you find far more non responders.
Fair point, and great work pulling that off. I still remember when my own fitness was at a level I couldn't imagine doing a climb like Hotham - while I have done it more than 6 times now they certainly weren't all in one day!
I'm very average - just turned 50, semi-regular MTBr - Have completed the "3-peaks" incl "The Meg" (which I had never ridden before), and watched many walk while I stayed in the saddle - but I have MAD respect for those (2 so far that I know personally) who have 'Everested' - these levels feel exponential in nature...
Nah, if you can do 3 peaks you can do an everesting. It might be twice the elevation gain but my own everesting was actually a shorter distance and probably only took a couple of hours longer than a typical 3 peaks' time.
Perhaps not but the average cyclist isn't going to ride for 24 hours straight or whatever is necessary for a climb with a lower gradient either. Anyway I was only responding to GP's suggestion that their own effort was achievable by an average cyclist.
That’s not the point they’re making, I think - they’re giving praise and kudos to the post above, saying they’re better than “very average” if they’ve pulled off that ascent 6 times
EDIT: Maybe average within this “hell 500” or whatever clique.
But: Saying that you are just average compared to the general population when you are clearly above average is humble. Saying that you did six laps compared to George Mallory’s eight laps[1]—which forced him to get up ~before sunset in order to be able to ride his bike all day up and down a mountain/hill—is just a humble brag.
At some point the supposed humbleness loses all suspension of disbelief.
[1] Getting up to a best of six laps still took George Mallory from about New Years Day until Autumn.
I’ll kindly ask you to stop misrepresenting my remarks. There is nothing humble about them. It’s unqualified outright bragging. I’m extremely proud to have achieved this.
The motivation of my further comment in regards to being average, that is to say, a very ordinary person, is to encourage others that similarly want for any particular athletic gift, who may look at this sort of thing and might like to have a go, but aren’t sure of themselves, and it’s to them I say, you can do it, because I did.
Man that is tough, and only about 35% of the way there. Now, a lot of the distance/time comes from transits between the various climbs, but man. I guess if I spammed a single hill in that I'd guess Everesting would be the equivalent timewise/effortwise of about that plus 25-50%.
So you pick a hill to do it on. First of all, get a triple and the biggest rear cog you can. THe key to non-pro-bike-rider climbing is getting lots of gears. For hills all road groups are hilariously too coarse for real sustained climbing. Lance Armstrong, pinnacle of the EPO era, was famous for high-rpm cycling and let's face it, his sustained Wattage output (to say nothing of watt: weight ratio) was 2.5 to 3x what an everyday cyclist could sustain. And yet he probably ran the same 53/39 and 11-25 groupset that they sell at the LBS. Yeah he was spinning a bigger gear, but the point is HE'S 3-4x THE POWER/WEIGHT RATIO and on the same gears.
So get a triple (52-40-30) and go to MTB on the rear if you have to to get to 30+ rings on the back.
Then, weight weeny everything else. Especially your wheels, climbing is about imparting and losing angular momentum to the wheels as much as the actual overcoming of gravity. Protour riders used to have certain ultralight rims IN THEIR CONTRACTS insisting the team provide them regardless of their equipment sponsorships.
Now, what's the best hill to pick? This is all about long term endurance which means Zone2/Zone3. It's 8800m. so...
5% grade: 20x vertical height so that 180 km/112 mi.
10% grade: 10x vertical height so that's 56 miles.
7% average is probably the sweet spot. Not so slow that you're losing your mind, Not so fast where air resistance comes into play.
You'll want a hill with a far steeper descent that ends up in the same place.
You'll want a hill with smooth concrete. Once you start getting tired, every crack, bump, and hole becomes misery and momentum killers. Bike climbing is about sustaining momentum.
But finally, you'll want a hill with a tailwind. Oh yes, it matters a lot, every percentage point is very viscerally felt when climbing inclines. You'll generally be sitting up in the saddle, and a tailwind that is >5mph will be PUSHING YOU, with your body as a sail.
If I could find a 8% Grade climb with a 10+mph tailwind on good concrete a well setup bike, this is probably easier than doing an Ironman (2.4 mile swim / 112 mile bike / 26.2 mile run) on courses like Ironman Wisconsin (where the bike is basically Horrible Hilly lite).
I'm assuming you get a refill/refuel provision/support? Don't carry excess liquid and food!
These days you can get a 12 speed Gruppo and get even more favorable gearing ratios, ie 48/30 and 10/36. And it will be lighter than an 11 speed triple.
Remember that if everesting for time you will want as large of an outer ring upfront as possible.
Can partially confirm. I hiked to Everest Base Camp and the air at 5300 meters was significantly thinner. It's no surprise that at the top they use oxygen.
This is interesting. It seems like the general idea is to climb the equivalent of the height of Everest from sea level (8,848m/29,029ft) in one activity with no sleep. Which, according to my understanding, is quite different than actually climbing Everest, which is normally a journey of several days that starts well above sea level.
How you manage the climb can be quite an individual challenge too.
Picking an incline I've traversed a few times in trail running events, up to highcliff nab near guidsborough which is about 170m climb over ~800m distance, you'd need to go up and down 56 times which I think is eminently doable (though far from easy) between sleep periods. I'd need a few leg rest breaks! While I'm certain I could physically do it, whether I could face the idea of actually doing it is another matter: endurance challenges can be a mental game as much as a physical one.
If you skip the steepest part and do between the bottom and the track to Sutton that is ~100m height over ~550m distance, I think that would actually be more manageable though you miss out on the view from the top each time.
Depending on your training for climb you might find it much easier to do a less steep incline, climbing the same amount over a longer distance possibly in a similar time, though for an Everesting challenge going steep feels more right.
I'm thinking about this too much. I might be in danger of setting myself up for an Everesting challenge. I wonder how many times I'd have to go up & down the hill up to the local University…
----
Edit: hmm, that little hill is only 14m over 500m apparently. I'd have to cover 632Km and the longest I've ever done in one go is 129 (80 miles), that with just ~800m total ascent. Maybe this is not nearly as do as doable as I first thought! Maybe I'd do better going shorter & steeper. When the lungs have recorded from what covid did to them I might have to try train myself up for it.
What is really really funny to me is something like Mt Kilimanjaro. Obviously 10,000 feet shorter so an entirely different ballgame, but climbing it for the general population is like 7-8 days. I believe that is stictly the climb up time, although I may be wrong.
Anyway...
Kilimanjaro is a very accessible mountain for the ultra runners though. Kilian Jornet went from base camp to summit AND BACK in 7 hours 14 minutes, summit time was 5 hours and 23 minutes.
Karl Egloff has summited in 4:56.
I really really want to know what some sort of EPO'd up superelite runner could do up Everest. Especially since almost all the tourists use supplemental oxygen.
So if you're in 50% of the shape of Kilian Jornet, then you could theoretically summit in 11 hours. Now there's a lot of danger involved in that, you need to determine if you get bad altitude sickness or hemmoraghing, so a lot of test runs up smaller summits is obviously required.
Anyway, you have these tourists taking 7-8 days, and some runner does it in FIVE FREAKING HOURS. Imagine hiking along and some runner comes scorching by and knowing they are going up and down the mountain in a time less than your daily hike that day.
Back in my ironman-finishing (not Hawaii-class) I was considering training to do that. This Everesting thing would be a great peak ironman training day.
I have a soft spot for these kind of "meaningless" challenges. Personally I'm now trying to figure out how to ride a 100K, but using the least amount of road to do it. So basically riding 3-4 hours in a roundabout is the best. Challenge is finding something with the appropriate radius. Too small and it's hard to keep up the speed.
Another one I'm doing is using wandrer.earth to track the amount of unique roads I've traveled (so opposite of 100k challenge). Trying to cover every street in my city.
Some college guys I know rode 200 miles around essentially a big roundabout (the loop length was probably less than 300 meters) at 20mph. When asked why they did it, they basically just shrugged and said they thought it would be a cool challenge. And I guess it was.
Funny i have no problem doing a 100k, but i tried what you mentioned, i found a nice 1K loop but at 25km i couldn't handle it mentally anymore and never got do it it despite multiple tries.
I have a 1K loop near me and I had the same idea. The most I've done is about 20KM before the boredom became too much. I'm starting to think that dealing with the monotony may be the challenge itself.
I did try with a ~145m loop here, but it was hard to keep up the speed. Turns so tight I couldn't do them much faster than ~27km/h, and then I would be stuck there all night. So did 100 laps out of ~700 before I caved in haha. Found another one here that's ~700m, but it's actually quite hilly and had bad luck with the wind being against me going up the hill, so caved in after 33 rounds. Will try this round again with a faster bike and better weather, though ideally I'd like a shorter and flatter one.
But yeah, combating the boredom is somehow the alluring part for me. Just zone out and do it. I've biked 300km races and similar, so the distance isn't the problem.
I trained for one hike by going up (and down) the stairs to the 13th floor in our apartment building 10 times with 25kg backpack every day for a few days. That's like 500m of gain. Just 18 times this and I would be on top of Everest
In Haifa (Israel) there was a staircase race a few years ago, from sea level to the top of the city going up more than 1000 stairs. One version of this was doing it over and over so that the total is the height of the Everest. I'm pretty sure there were several runners who finished that successfully.
There was a similar challenge in France recently - we were limited to 1h of outside exercise in the radius of 1km around your home during the Covid lockdown.
The challenge was to do as much vertical ascent as possible under those condition (granted, the conditions were very dependent on where you live).
Unfortunately, nothing quite compares to the rise in elevation like it does in the Himalayas. On the first day of your Everest Base Camp trek, you have to go from Lukla (9,300ft) (airport where you land if you go from Kathmandu, Nepal) to the first camp, which is right below Namche Bazar (11,000ft).
The rise in elevation combined with carrying a 40lb backpack (average), and the difficult terrain leads to levels of tiredness that you can't quite achieve in any other scenario. A lot of it has to do with elevation of course, but the terrain on that EBC trek is absolutely ruthless.
That first day when we got to the first camp, I have never ever in my life been that tired, and even my guide who was with me - advised me not to sleep too much as it will make it worse.
I'm living next to a 1,800ft mountain right now (I'm in Norway) and I can do the roundabout hike in like 2 hours and yeah it stings physically, but it is maybe 1% of what you will feel in the Himalayas.
I'm not sure I could find the correct scientific paper on it, but I do believe it has something to do with altitude sickness. I do know that at the last camp (17,500ft) it was near impossible to sleep because of shortness of breath.
It requires about the same amount of effort I have put forward to not read the link, make some sort of weird braggy- unrelated- post so I can’t figure why you’ve taken the time to reply to me. To be honest typing this is the extent of how much I care. Farewell.
The fact that this requires climing the height of Everest from sea level dovetails with something I've been thinking recently, which is:
How much harder would be it be to climb Everest (or Denali, or Kilimanjaro, or...) if you chose to start from the nearest point at sea level? IOW, no getting transported to Everest base camp by vehicle and getting that 5km of vertical ascent for free; walk the 400 miles from the Bay of Bengal to Everest's peak on your own two legs. I think this would be a fascinating routing problem. If anyone's done this before, I'd love to know.
Kilimanjaro has high prominence so getting there from sea level probably won't be that much trouble as it's only a couple hundred miles from the coast and there are paved roads for the majority of the way. Wildlife and some locals could be an problem but odds are that you would be fine. It really comes down to if you're allowed to stop in at convenience stores along the way for food and beverages instead of carrying all of that with you.
I 'climbed' Mauna Kea (mostly driving to the top, with a short hike from the parking lot). 13803'. Simply walking at that altitude, which is less than half the height of Everest, was so uncomfortable that I couldn't wait to descend. I can't imagine being at 29000 feet. I imagine it would feel like a living death.
It's not Everesting without the "Cross the Crevasse" experience, and your Sherpas thinking the money you pay them, it's not worthwhile the Babysitting... - https://youtu.be/G4ZrD7IoFlo
Wow, didn't expect to see this appear here! I can't claim to be an early achiever, but I do know A.v.B and some of the people that did the original attempts, still remember being blown away by it when I saw the Strava uploads.
Technically it's slightly lower surprisingly early in the trip -- get to an altitiude of 500km and g is down to about 8.5m/s, at 2000km it's 5.7, and by the time you get just 1/10th of the way it's pretty much gone. At some point the moon's gravity will start to work with you and pull you in.
According to Wikipedia [1], Gordon Pirie ran 347,600 km in the 40 years to 1981. He lived another 10 years after that, so he might have come close. The distance to the moon is 384,400 km.
It sounds like a fun challenge though I must say that I've heard not once, hikers describing a trail's total elevation gain as being such and such times "climbing Mt. Everest" (when trying to say that the total elevation was some multiple of 8848 meters). Even if you discount going back and forth between camps for carrying gear, the total elevation gain of climbing to an altitude of X meter will always be significantly larger than X (unless maybe you're climbing stairways).
My go to local hike starts at 450ft above sea level and goes to 1150ft sea level. However it has many ups and downs so the total ascent is ~1250ft. To the top of the mount/hill and back to the trailhead is roughly 4.5 miles. So to "Everest" on this hike using total ascent numbers I would need to do this hike 23 times, which would cover about 105 miles. Seems like I would need to take up extreme trail running to accomplish this in one go. Interesting idea but probably not for me.
Most competitive Everesting attempts use a steep and typically short road. 3-5 miles of downhill on a 5-6% gradient is probably too time consuming (i.e. too much time spent not ascending).
Ronan McLaughlin, the current mens' Everesting record holder, used a 12%, 800m long segment:
IIRC from a video I saw about it the prevailing wind is up the valley, so he got a bit of a tailwind on the ups but the headwind on a 12% descent didn't matter.
The steeper the better, so you dont waste time coasting or softpedaling or lose velocity to air losses.
Steepness is also good for the descent, getting you up to a good (terminal) velocity.
It also helps if the segment is straight such that you dont need to corner.
IIRC the ones who were competing for the record didnt make the effort/recovery trade off consideration, their limiter was the segment.
I dont think they've found a longer perfect segment yet apart from the one in GB.
But from what I#ve seen the optimal ratio was 3-4/1 asc./desc.
There is a ski resort nearby called Wintergreen and a cycling time trial up the road to the top every year. I was not aware of it until I got into cycling for a bit about 10 years ago.
The road averages 7.7% grade and has switchbacks that are 15% with total elevation gain of 2900 feet.
That could be a good hill for this if cycling at a high enough level. Would be best to have a vehicle bring you down each time.
I did the time trial and had to walk up portions. Surprisingly I sprinted at the end when my nephew ran with me up the final climb to the finish. I doubt I'll ever get to that level of endurance again.
>>Would be best to have a vehicle bring you down each time.
Indeed! Except under "Single Climb" in the rules, it is forbidden
>>– Each repeat must be ridden up and down (i.e. you can’t get driven down each time). You also need to keep your device recording the whole time.
For the Mt Washington hillclimb race, unless you have disk brakes, it is required to descend in a car because your brakes or tire will not survive the descent and you'll go off the edge...
Wintergreen Ascent TT disallows cyclists going down at all. I've been down some mountains going faster than I should have, but Wintergreen is one where if you make a minor mistake you could easily end up in mortal danger (at least that was my fear at my level at the time). Also, the road isn't closed to traffic during the event which makes downhill even harder during that time. I don't think a reasonably high level cyclist would have a problem going up and down a few times in a day though, which could of course be done at any other chosen day of the year.
I've been to everest base camp. The distance up everest or the delta of the elevation gain isn't the hard part.
The hard part is the weather and lack of oxygen. This "challenge" doesn't even compare. I mean nothing wrong with making a "challenge" but I think "everesting" is a bad name.
Also good for folks to realize base camp is at 17k feet and you typically go up to 4 higher levels of camp over the course of a few days. You aren't climbing 0 to 29k feet in one day--at most it's more like 4-5k feet in one day.
How is that “good for folks to realize”? No one is taking this challenge as an analog to climbing Everest. People are not out packing their bags to go to Everest after having done this.
The challenge is literally called "everesting". Your brain is working in a weird way if you're trying to claim there is no analogy or parallel being drawn here to climbing Mt. Everest.
The point being made, which in your fury you seem to be completely missing, is that climbing Mt. Everest is actually _easier_ than this everesting challenge. A guided climb of Mt. Everest would have you doing no more than about 5k feet of elevation gain in a single day. Over the course of a week you would work up to acclimating and preparing for the summit push. This challenge has you doing 29k feet of elevation gain in a single day--even at sea level and on a bike that is a tremendous leap in athletic challenge.
Btw, Everest and many other mountains are included in Wii Fit U when you have the fit meter, which has a basic altimeter. The game has both distance (walking and running) and height challenges. My SO and I had a lot of fun competing.
This might be a bit too extreme. But any other reasonable sporting challenges outside the popular marathon/ironman/70.3 which average athletes with family life can approach?
I would rather run-job 50 miles and get sleep. That seems stupid.
The line I draw in endurance is sleep deprivation. I'll stretch it to a 20 hour thing, but that's it. IMO if you are doing endurance activity (already questionable health-wise for anything over a couple hours IMO) with little to no sleep, then it doesn't seem like an actual positive thing in your life.
I have no problem with the idea of Everesting; the issue I have is with a person I know who has made their entire identity revolve around it...but that's for another thread.
People, we do not need 100s of comments detailing why this is not like climbing Everest at all. Everyone with a modest level of intelligence is already aware.
“Everesting” is a tongue-in-cheek term for doing some physical activity with an elevation gain of 8,000m and some change.
Elevation gain is a measure of vertical distance. It is a common form of measurement in events like this.
For example, ultramarathons will often tout something like “20,000 feet of elevation gain!”. This does not imply the ultramarathon is run up a 20,000 foot mountain but rather implies cumulative elevation. This is what Everesting implies, as well.
Altitude is generally the distance from sea level and implies other factors in this context, namely atomosphere thinning.
People don’t summit Everest in one go from 0m -> 8848m though… in a “single activity”. I don’t know how far up the Everest base camp is but it’s not on sea level.
In the limit, if the height of Everest goes to infinity and the base camp is say 2000m below the summit; Everesting would become impossibly challenging.
It's funny when you notice that, while bikes are great on a level surface they're absolutely awful at anything moderately steep. Yes, even a multispeed bike.
Doing it on foot sounds easier. Unless you're talking about a very shallow inclination
A lightweight bike is ~6kg, what you gain from not having the impact of each step and being able to control your heart rate while keeping your cadence optimal via gears IMO more than compensates for the extra weight.
Standing takes a lot more energy than sitting - remember, the challenge is coming down again as well on each lap, but even on the uphill not having to support full bodyweight is an advantage, instead you just push with the effort you require on the pedals.
And of course if you are in the wrong gear a bicycle will be ineffective... that's why you choose the right gear?
Interesting that people use "shallow" as the opposite of "steep" (for an ascent), when it isn't really, and certainly it sounds odd to say "a shallow hill". I prefer "gentle", but I've always wondered if there are other languages that do have a specific single word meaning "not steep" that you can use to describe mountains etc.
At any rate, it depends a lot on the surface, the bike, the length and the sort of muscle development you have in your legs. For me on a decent road bike on a smoothly paved road, anything up to about 15% for a km or so is definitely easier than walking - I can do it a lot faster for a lot less effort. But on a loose gravel/heavily rutted surface, I'd probably have trouble staying upright for long at 15%+ on a typical road bike, and even 15% on a smooth road for much more than a kilometre gets very tiring (accepting it's pretty tiring to walk too, but it seems to put a different sort of strain on your muscles). I'm not sure if you'd consider 15% "very shallow" (I certainly wouldn't call it "very gentle"!).
Don’t forget about descending, which you will do a lot of in this challenge. Descending on your feet takes quite a bit of effort to control and stabilize your descent, and is also relatively high impact. Descending on a bike, on the other hand, requires basically zero effort aside from squeezing the brakes.
Pedantic nitpicking aside, George Mallory (who has done both, and is essentially the godfather of this cycling challenge) was reported as saying the bike ride was harder¹.
Alas, I have so far only completed one of the two, so I cannot compare for myself.
However, for those especially keen, the Hells 500 group also recognises a separate 10,000m “high rouleurs” challenge, albeit with more relaxed rules about route and (optionally) sleep.
Perhaps but it's the extremity of the conditions and the stresses they put on your body that makes it dangerous and I would think a good deal more difficult than climbing a 2000m peak in a temperate climate.
My grandfather and his wife attempted to climb the tallest mountains on each continent. While he climbed K2, they failed Everest when her rib cracked and they had to descend not too far from the peak.
He pushed himself to do a bike ride the same number of meters and said it was significantly harder than K2.
