Everesting on a single speed?
 

I had a probably very dumb thought--if you could find a really, really consistent hill for an Everest (e.g., let's just go with a steady 4% with no more than 1% variance in either direction), shouldn't a SS bike be a pretty good candidate?

Potential advantages:

• Shave a couple of pounds of weight
• Being able to sound like a badass when you tell people the story some day
• OK, well, that was really it.

Potential disadvantages:

• You get tired and can't finish without a cog swap.
• Settling on a lowest common denominator gear means you have to spin like a maniac and it still takes forever
• "Everests are hard enough, so stop being an idiot."

I WANT to believe I could find a gear that would give me the desired average speed at about 90 rpm, allowing me to dial it up or down and still get there, but I'm probably wrong, and it would really only be for the story.

Thoughts?

As long as it doesn't get so steep that you have to get off and walk, I would not worry about a little variance in slope. That variance will give you a chance to change your cadence now and then, which I find helpful on long rides. Obviously you don't want to spin like a maniac for long stretches, but spinning like a maniac every now and then is not such a bad thing. I did a very flat 200k on fixed gear last year, and the constant cadence got to be a real pain in the ass. Now and then I needed to get out of the saddle for a while, and the only way I could do that was by going slow, holding the brakes. That was my only complaint, though, and I don't think you'd have that problem.

So the plan would be to spin up the hill averaging 90 rpm or so, coast back down, and repeat repeat repeat? I would have a hard time working up the enthusiasm for that, regardless of the bike, but if you don't have that problem, I think you'd be good to go.

A 4% slope would make for a long ride to get to everest elevation... like 400km I'd guess... There's an everesting calculator out there you can plug strava segments into and it'll tell you how long the ride will take and all that jazz, fun to play around with.

I think my carbon roadie is lighter than any of the single speed bikes I have. Probably better to just make a 1x hill-climb bike with a really light corncob cassette on the back and a smaller chainring. Could just run one brake up front and use downtube shifters if one were building a specific bike for everesting I'd go with something like that in theory. Run a superlight tubular wheelset too and all that other weight weenie kind of stuff.

Yeah. My coworker did his on a 4% average, but that was a double everest, so I'm sure he chose it because he knew he'd have to pull almost 60k in elevation and wanted to have something left.

I ran a 28 X 13-21 when I climbed Mt Washington. Except for the flat 1/2 mile to the base from the start at the tollgate, perfect. I've done a bunch of lesser but still long climbs on fix gears. Up Mt Ashland and up Dead Indian Memorial Highway on a 42-23. Mt Diablo many years ago on a 42-17 back when I never changed gears. Now, except for Mt Washington, none of these were races or recorded but several were parts of epic days.

A lot of this is mindset. Being comfortable out of the saddle counts for a lot. Now, 90 RPM sounds like a lot to me. I'd be thinking closer to 70. But then, I've never been a spinner uphill. IF I geared that way, I'd just slow down.

Ben

This question reminded me of when Paul Rozelle climbed Venteux 3 1/2 times on a fixed gear. But that was "only" 16000 feet. Paul Rozelle?s 24-hour, pre-PBP, fixed-gear, Mont Ventoux ride | The Bicycle Story

Most climbs I would consider an Everest attempt have tricky descents, so not a good place for superlight tubular wheelset and only a front brake, especially when you're fatigued from hours and hours of climbing. The only place I might consider it would be Monitor or Carson Pass in the Sierra Nevada, with smooth pavement, gentle curves and good sight lines.

Yeah, totally depends on the local topography. Around here I have no large climbs to do everesting, the biggest hills anywhere close to here are 30m or 40m perhaps. There's been a few riders that have done it on the short steep hills we have. I was looking at one hill I like to ride and it'd be a 197 laps of it to everest. I probably wouldn't bother trying it with my theoretical setup since I don't have fancy light wheels and I like having two brakes too.

I just ran across this today: Everesting on a fixie with a hormone headwind.

I remember seeing a youtube video of a guy doing that (fixed gear)- maybe in London.

He went up a modest urban hill all night and more, coasting down w/ feet off the pedals.

197 laps- that's not many.

lol that's a lot of repeats! The one I had in mind has bad elevation on the strava segment, ~20m instead of 45m so I'd be over 400 for sure. I think I'd just drive to a slightly longer hill and do less repeats, dunno if I ever will try it or not.

I've mapped out routes with 12 laps (2,443'), 20 laps (1,480), and 33 laps(875).
I've done close to 20k on a DC, but only 10k strictly laps- don't know if I'll ever do it either, & certainly not on single speed.

Laps don't count. The ascent and descent must be the same road/path/trail/whatever. So in order to count, it's hill repeats. The grade needs to be steep-- the nutters really going after it are only looking at +12% average-- unless you want to spend 24 hours grinding it out.

A hill like the one Contador used would be fine on a SS, you'd just have to find the gear ratio you could comfortably climb it on, then just coast down. His hill was under 1km long, and he repeated it less than 80 times, IIRC.

If that was referring to my post, the laps are up & down the same climb.

It doesn't seem like the grade would change overall time much since steeper ascents would be at a slower speed, unless it was so flat that the descents were slow.

Contador's strava is pretty interesting. Too bad I can't climb that fast on 250 watts. https://www.strava.com/activities/3721627590

Would have been interesting to see his data with power. His average speed is 12.2mph, but he averaged ~43mph on every descent, and broke 60mph multiple times.

Even at his flyweight, it would have taken his ~365W for an average ascent early on. By the end, he was probably somewhere in the 270-280W range... which is less than what I would have to put out just to avoid tipping over on a 13% grade.

did I misread the power for each climbing segment?

Most segments are 350-ish and the low power ones are 250-ish. My 4 minute power is nowhere near 350, but 250 is doable.

Beryl Burton would’ve done it with a 52t ring driving a 16t fixed cog.


i would not.

You might have better luck with a three speed.
https://cyclingtips.com/2020/08/6-2-...esting-record/

It isn't obvious from the picture, but given all the other optimizations I hope he straightened the chainline with those 3 gears by putting spacers behind the cassette as well.

I don't think he did put spacers behind. Maybe it's one of the newer cassette bodies where that's not really possible

If he moved the sprockets further to the right, would the parallelogram shape of the rear derailleur put the cage too close to the sprockets? I suspect that the last thing he wanted to do was to make any changes that had the potential to cause any shifting difficulties.

I suspect a better way to improve chainline would be to shift the chainring position with spacers. But, I am not familiar with that crankset and then frame clearance could be an issue too, so maybe that is not practical? From the photo, if any spacers were added, I can't see it.

Photo from article at:
https://cdn-cyclingtips.pressidium.c...3-1080x653.jpg

As chains get narrower with more speeds, is chainline less critical?

I have about a 5 or 6mm chainline error on my Rohloff bike, that has a relatively wide 8 speed chain and that does not appear to cause any increase in friction or reduction in chain life. I wanted my Rohloff bike to have a Q factor that was similar to my derailleur bikes, thus the crankset spindle is about 10mm shorter than it should be. But I would not want to have chainline error greater than that.

I'm sure the thought was that it works on a normal bike, it will work without the extra sprockets.
The people setting records now are doing it on steeper hills. Might be okay to climb on a fixed gear, but descending wouldn't be as much fun.

I did 50mi+ of 12%+ repeats on a badly (at least by appearance) cross-chained 11spd drivetrain, and while it never broke, looking down at the chainline as I rode was disturbing.

I don't know the actual % loss to efficiencies, but I'd read the larger idler pulleys were very marginal gains, so would think a straight chainline would have to be beneficial.

I think you're right on parallelogram though, at least for road components. A Shimano 1x MTB derailleur (spec'd for 46T but can fit a 50T), can at least clear a 32T sprocket in the 9th gear position (based on Shimano's 11-40, 11-42, and 11-46T cassettes). So if you are satisfied with 32T being your top gear, just put two gears of spacers behind it and set the limit screw (at least for mechanical).

An alternative might be an offset rear derailleur hanger. My Specialized Tarmac disc bike (first gen) had a wonky chainline spacing that required special hubs (135mm SCS) to mimic a traditional road 130mm, however they sold a derailleur hanger that shifted the derailleur outboard to allow regular 135mm hub to be used. It works great, and put the bike back to a traditional 135mm chainline ... add some washers and a longer rear derailleur fixing bolt and it could potentially space it out even further (or have a hanger machined with the extra offset), allowing a regular road derailleur to be used.

Leonard Zinn has written a few articles on friction losses, chain line, etc. I am not going to put together a list of articles, but this one article i found rather insightful.
https://www.velonews.com/gear/gear-issue-friction-differences-between-1x-and-2x-drivetrains/

It is easier to see the graph from that article here.
https://www.velonews.com/wp-content/...5%2C871?w=1080

Even with a cross chained drive train on the larger sprockets, the friction losses in watts were not much higher than with the sprockets that had a better chain line.

For my riding on my bikes, when I think about chainline, my primary concern is not friction loss and whether or not it slowed me down, my concern is reduction in chain life.

I have bar end shifters on two touring bikes. One advantage to that is I can tell from the feel of the lever position about where my chain is on the cassette, that makes it much easier to avoid cross chaining than with a brifter where I have no feedback on where I am on the cassette when I shift until I run out of gears on that chainring and need to change the front derailleur. Thus, I am often cross chaining with a brifter for the rear derailleur, but not when using bar end shifters.

Cross chained will be less efficient than straight, no matter what the gears used are. But those articles do make very clear that gear selection (i.e. an 80x40 would be more efficient compared to a 20x10 due to the less articulation angle/bend) effects the efficiency.

The stakes are high is this Everesting business :lol: and I'm sure future challengers will chase every marginal gain they can get. The oversized idler on Ronan's bike ranges $500-1500 based on options, and eventually people will run out of things to buy.

Another place to look for info on going fast with the least effort is the IHPVA (International Human Powered Vehicle Associations, ihpva.org) journals -- lots of scholarly articles (though dated) if you're trying to build bikes that people can beat the existing speed record of 89.59mph (or just pedal over 60mph+).

One hundred percent agree.

But an 80T chainring might weigh enough with the extra amount of chain you need, that lifting that extra weight up the mountain could negate your reduced friction. I will leave that up to the lab geeks to calculate.