MarcusT

On another forum, a member posted that they did a 25% climb with a loaded bike. My personal experience had me on a 15% climb on a naked bike and it was the toughest climb of my life. A quick search of the Tour De France and Giro d'Italia, the toughest climbs they have listed were mostly about 20% and these were pros on 12 lb bikes
Do you believe that was doable, or the gradient rating was flawed or just a miscalculation by the rider?

cyccommute 

On my “A Good Ol’ Fashion Appalachian Butt Whoopin’” the section from Asheville to Unicoi included a 22% grade. The highest grade I could find was on the second day from Pigeon Forge to Cherokee there were several steep pitches two of which were 23% and 24%. I didn’t walk those. My load was probably close to 60 lbs. My gear has decreased in weight significantly since 2012. My low gear is significantly lower now as well.

indyfabz

Such ruling grades do exist. ACAs route in Arkansas has sections around 23%. With low enough gearing and perhaps “delivering the newspaper”, one could probably get up a section of 25%. But not me.

BTW…You overlooked the Angliru, which has been used in La Vuelta. And I think 12 lbs. would be under the legal UCI limit.

saddlesores

sure, it's possible. but we need to define some terms.

what does loaded mean? 2 bags? 4 bags? 4 bags + trailer?
what's a 25% climb? was it a continuous 25% over 20 km in the himalayas, or a short 200-meter section in the ozarks?

i hit a 22% grade in czechoslovakia, a long grade over a couple kilometers with 2 rear bags, about 20kg. i didn't make it. one of my chainring bolts snapped and my inner chainring folded over. nearest replacements in vienna.

KC8QVO

You have to question how they are determining the 25% grade.

For example - my bike computer (Garmin Edge 1000) has enough georeferencing data when recording a ride that when I upload it (I use Strava) you can see the elevation grade metrics.

Therein lies the question. How are the algorithms set to compute the grades?

Here is an example from Strava from one of my days on my Ohio to Erie tour in '20. The yellow line is the marker for the ride route that was recorded. In the elevation graph under the map it shows the elevation over the path of the ride. That data doesn't just "show up" like that. The track is recorded as a set of "bread crumbs". Each bread crumb has georeferenced data on it. You need an algorithm in more sophisticated software to compute all of those "bread crumbs" together to interpret the data. No two softwares/algorithms will come up with the same identical data.

So the question is - how is the grade that you see established? I have no idea.



As to the question at hand on the 25% grade - was that recorded via GPS? What were the GPS conditions when that grade was established? Was there a GPS accuracy issue at that moment when the corresponding "bread crumbs" were recorded that throws of the algorithm from which the grade given was established? We don't know.

Is it possible that on a grade during a ride the recorded metrics could compute a "25% grade"? Absolutely. There can very well be a much higher grade recorded.

Does a really high recorded "grade" represent the actual grade over any meaningful distance? Nope.

If you take several data points over, say, a 100ft distance (as ridden - not horizontal - when you go up a grade you travel further up the grade than you do over the horizontal plane) and average them - does that give you a good representation of the actual grade? I don't think it does all the time. There are too many variables. And if you have outliers then they skew the data. You can get closer that way, yes, but it still isn't fool-proof.

Tourist in MSN

For me the limit was at the short part of a hill in Five Islands Campground on Bay of Fundy, Nova Scotia, Canada where my inclinometer said 17 percent. It got steeper, but I quit pedaling at 17 percent.



But, I was not trying very hard, heart rate was 105.

I camped there a few nights, I do not recall if the photo above was when I first arrived with a loaded bike or if it was while I was camped there and went over to the camp office to use the wifi riding an unladen bike. I climbed that hill a few times, when it got to steep I got off the bike to finish it.

One other bicyclist was camped at the campground, this was her first bike tour, she said she tried to make it up the hill and could not.

That was four years ago, thus I was 65 years young at that time. For me, I quit pedaling and start walking when my heart rate monitor says that is the right thing to do, percent grade does not matter to me, heart rate is the deciding factor. Or, for this hill, I knew that I could not climb it, so why try?

Every once in a while, someone asks me where to get an inclinometer like that. They are in stock again. But, you must be at a constant speed (no acceleration or deceleration) for it to read correctly. The bubble changes size slightly with change in temperature and barometric pressure, I leave mine loose enough that I can re-calibrate it (twist it on the mount by hand but tight enough that it stays there) to correct it for the uphill part of the scale when on flat ground. I have no connection to the manufacturer.
https://www.amazon.com/gp/product/B01L5GL3A8/

The original question was - is this doable? Mathematically, you probably could calculate a maximum gradient using a ratio of chainring to sprocket teeth, a ratio of chainring radius to crank arm length, a ratio of rider weight to weight of rider plus bike weight, and figure out how much momentum you would need to maintain during the most powerful part of the pedal stroke (crank arms nearly horizontal) to the least powerful (crank arms roughly vertical) and back to the most powerful part of stroke to come up with a theoretical limit based on whether or not the rider is lifting with one foot or has no pressure on that foot. I will let others play with that.

GhostRider62

Each MPH and percent gradient takes my loaded bike 5 watts. I just do it in my head.

1 mph and 1% is 5 watts

10% and 5 mph is 250 watts.

25% and 5 mph is 626 watts,

25% and 3 mph is 375 watts.

When I was a young racer, I did a loaded tour thru England, Wales, and Scotland. Climbing a road with a 25% sign, eventually I fell off.

Currently, I can suffer over 20% climbs on a stripped down carbon racing bike. Extended climbs of 20+ % are rare (not talking about little pimples)

irc

Who knows? Does it matter? Once my climbing speed is down to 3 or 4mph I am happy to walk. Uses different muscles. Almost a rest. I certainly couldn't ride my touring bike up a 25%.

I don't know the grade but at the end of a tour that finished in San Francisco I rode my unloaded bike up a stupidly steep hill. A tough climb even standing out the saddle. Strangely enjoyable because I probably couldn't have done it without the 2 months daily riding that preceded it. But I'm not built for climbing.

GhostRider62

It doesn't matter. Who ever wrote it is wrong. True 25% extended climbs are rare, climbing them with a fully loaded touring bike is not believable.

pdlamb

I'm skeptical, and not only because I couldn't do it. But it might be possible.

I'd like to see a video, preferably taken from the side of the climb.

cyccommute 

What’s that? Not familiar with the term.

indyfabz

Weaving back and forth across the road to cut down the grade. Also known as "delivering the mail."

Xavier65

A few months ago, on a 25Kg bike with 20Kg luggage, I (110Kg) started a 10-20% ascent of about 45m over 300m of tarmac. Despite an ultra low granny gear (12 gear inches) I got off halfway, at 15%. Walking the bike was a more efficient use of my energy.

So, at a certain gradient, remaining on the bike becomes a matter of brawn over brain.

But, yeah, there are YouTube videos of ultra fit chaps doing 40% inclines on lightweight road bikes, e.g.

ThermionicScott 

Or "paperboy."

Tourist in MSN

I have done that but I called it - making my own switch backs.

Tourist in MSN

I think we have all seen short steep hills, but this was the steepest extended hill I have been on for a bike tour, when I got to the sign that said 13 percent grade for kilometers, I got off and walked it. But, I was aware of that hill months before when I planned my trip, planned to walk it. Took the photo at 6:20am, I wanted to beat the traffic if I was going to be walking up a long hill with minimal shoulder.



I have posted the above photo several times before.

Took the photo below two hours later. I think that was near the top, but I could not tell if it was the top or not at the time, visibility was poor.

MarcusT

Thanks for the input. Of course, I'm not longer in shape to even consider a climb like that. I was just curious, especially since I was present at some of the steeper climbs in the Giro d'Italia and I saw the faces of these pro racers. They were not pretty.

bbbean 

I believe it is entirely possible to do that, but strongly suspect that 25% was the max grade on a milder climb.I routinely see climbs of 8-12% that will have a few meters of a >20% grade. That doesn't make them 20% climbs. Some apps will report a max grade on a given climb, but just as your max speed isn't the same as your average speed, max grade doesn't really tell you too much about the climb as a whole.

Of course, this is the internet, so it's reasonable to expect some mythic heightening. My last race featured a max grade of 11% and a max speed of 47 mph. That sounds a lot more impressive than an average grade of .6% and average speed of 21 mph. If I were to report that my last race was 30 miles of 11% at 47 mph, you'd be a little skeptical, wouldn't you?

tcs

On the internet, I'm 6'2" and often mistaken for Keanu Reeves.

xroadcharlie

According to "Bike calculator" a 160 lb person on a 25 lb bike carrying 25 lbs of gear climbing a 25% grade at 3 mph requires 330 watts. That must be tough even on short runs. But yes, I could see it happening with very low gears by a by a fit, athletic and very determined rider. Certainly not me.

The "We" part I seriously doubt, Some in that group probably had to walk unless they are all elite cyclists.

abdon 

That's most definitely a fish tale.

I used to cycle in Japan where the mountain roads are conveniently marked for grade. There was a particular one with an 18% incline that was a monster. I would be pedaling off the seat on 34 cog 28 ring. I have done 25% on an empty bike for probably 150 yards, you really have to be in love with hills in order to do that.

Loaded? I call bull.

GhostRider62

That would be 4.55 W/Kg. Cat 2 neighborhood according to Coggan's W/kg chart. Probably equivalent to a 2:45-2:50 marathoner. Not impossible. I walk those kind of hills unless they are pimples. Keeping the front wheel on the pavement is the biggest chore.

KC8QVO

Off topic, however I think the above quote is important enough to bring attention to it. This is an often over-looked aspect of a tour. As you note, though - if your route has you going through an "iffy" area - especially with traffic (and semi/truck traffic exacerbates the issue) - timing is everything.

Well played and well planned. I'm sure with as far ahead as you planned that trek there is a reason that grade was chosen even with the safety issues.

Hopefully the thread and the point you made here rings a bell with others as they are looking at the details planning out their own treks.

Tourist in MSN

There were no semis on that road, it went through Highlands National Park on Cabot Trail. But, it is the kind of place with RV drivers and others that have not been on the road before. And drivers that are not used to going down hill may learn the hard way how well their brakes work.
https://www.cabottrail.com/map.html

And with occasional fog, ... you get the idea.

The night before I stayed at a hostel, thus did not need to pack up my tent and camp kitchen in the morning, was a lot easier to get an early start that way.

nomadmax 

I'm with him ^

SHO me