I've driven up to the visitor station but not up to the summit - what are the road conditions like beyond the visitor station, where can you refill water, and should I prepare for anything beyond a leg crushing day?
I'll be starting on Kona (west) side, in September, and am expecting about 6-7 hours of straight climbing.
Here's about all I know so far;
Mauna Kea, Hawaii, HI
This mostly paved climb is perhaps the largest rideable climb in the world. The first 34 miles are paved, then 5 miles often loose cinder gravel, and then 3 final miles of pavement. The first 28 miles up Saddle road from Hilo gains only 6600 feet at modest grade, tapering off to almost flat in the saddle between Mauna Loa and Mauna Kea. Turning off onto Mauna Kea Access Road is a real shocker, as you are now faced with sustained 17% grades at high altitudes. The Fiets index for this climb is off the charts at nearly 30. It’s a combination of net gain and high altitude driving the high rating. Like Haleakala, views are too good to describe with words. Many of the world’s most powerful telescopes are at this summit.