To the argument about "best" vs. "hardest". I would still at Mauna Kea in the "best" group. It's just freaking epic to ride from the ocean to almost 14,000' in one fell swoop. Not to mention the moon like scenery. With the right bike the gravel is very rideable. I did it on a 34x32 with 25mm tires (WRONG tires), but that gear with something like smooth 30-35mm tires would be just fine I think. I'd love to get dropped off in Hilo, ride to the top and then down to Kona. It would be epic.

Digging up this very old thread with two questions …

1. Why does Mauna Kea seem to be so much more popular than Mauna Loa? Mauna Loa seems significantly more accessible, no walking, or weird equipment choices needed. It’s just the altitude and epic-ness of MK that are appealing?

2. You think smooth tires are ideal for the type of gravel on MK?

ETA: So I’m contributing something to this thread I’ll say the ‘best’ climb that I’ve done is Mt Lemmon and the hardest by a very long shot was Lincoln Gap in VT. My favorite that I do regularly is the Kanc in Lincoln, NH.

Personally, Lemon isn’t on my top 10 list. It’s ok, really just long and not difficult (in either direction).

First here is Mount Washington for reference - 12 km 11.9 % http://climbbybike.com/...p;qryMountainID=7704

Viderjoch - Switzerland - 11.3 km 11.88% http://www.quaeldich.de/paesse/viderjoch-pass/
Zillertaler H�henstra�e - Austria - Many variations all between 10-12 km and around 12% http://www.quaeldich.de/...taler-hoehenstrasse/
Monte Zoncolan - Italy - 10.2 km 12% http://www.quaeldich.de/paesse/monte-zoncolan/
Berbenno-Caldenno - Italy - 15 km 13.4% http://climbbybike.com/...;qryMountainID=14638
Monte Baldo - Italy 11.79 km 11.5% http://climbbybike.com/...;qryMountainID=12283
Aschau - Austria - 12.61 km 12.4% http://climbbybike.com/...;qryMountainID=12034
Hafelekar - Austria - 11.35 km 12.1% http://climbbybike.com/...;qryMountainID=11890
Grosser Oscheniksee - Austria - 12.2 km 11.7% http://climbbybike.com/...p;qryMountainID=1373

Others that are shorter but steeper:


Nebelhorn - Germany - 8.8 km 14.2% http://www.quaeldich.de/paesse/nebelhorn/
Scanuppia - Italy - 7.5 km 17.6% http://climbbybike.com/...p;qryMountainID=3597
San Genesio - Italy - 6.9 km 15.3% http://climbbybike.com/...p;qryMountainID=3498
Kitzb�heler Horn - Austria - 9.7 km 12.9% http://climbbybike.com/...p;qryMountainID=1318

Some which are longer and slightly less steep:

Grammont - Switzerland - 15.3 km 10.5% http://climbbybike.com/...p;qryMountainID=9572
Pico Arieiro - Portugal - 17.06 km 10.2% http://climbbybike.com/...;qryMountainID=15751
Koralpen - Austria - 15.4 km 10.8 % http://climbbybike.com/...p;qryMountainID=1321

Tons of others in the last two categories as well. And don't forget the Stelvio, Angliru and Etna.

Sorry I only got 8 roughly fitting the characteristics of the Mount Washington climb, but I think all of them at least as hard if not harder just going on the numbers.

Most memorable climb for me in the USA is probably MT Greylock in Massachusetts. Did a 90 km loop starting from Windsor Lake park just outside of North Adams which included Greylock. Not sure the numbers, but it was hard going up, fast going down, and scenic for much of the ride.

Greylock is a nice climb. Not in the upper tier of "best in the US", if you ask me, but really really good. Solid.

I haven't ridden it, but I have drove up in a car, whiteface should be mentioned here. Someone prob mentioned it in all the earlier pages of the thread but since we're on the topic of east coast climbs.

I have riding from Boston to Greylock and doing the race up Whiteface on my agenda for 2022.

You just don’t find a sustained 20 percent pitch at 10,000 feet above sea level anywhere away from the equator because it isn’t possible to stay on the road with even a little snow.

In the US: Pike’s Peak (CO), Mt. Evans - the road above the tree line sucks though (CO), Lemmon (AZ), Kitt Peak (AZ), Mt. Baldy (CA), McKenzie Hwy (OR), pretty much any long climb close to summit county in Colorado, Mt. Mitchell (NC), Mission Ridge (WA), Mollogon (NM), up to Pinos Altos in either direction (NM)

I haven't ridden it, but I have drove up in a car, whiteface should be mentioned here. Someone prob mentioned it in all the earlier pages of the thread but since we're on the topic of east coast climbs.

My favorite on the East Coast isn't insanely difficult, but does have a couple switchbacks between 15-20%. The views are great, but traffic can also be an issue.

Either Gatlinburg or Cherokee to the top of Clingmans Dome. Starting at Gatlinburg does give you about 2k more feet of climbing. But the ride only tops out at about 6600'.