If you have been riding, do not try to acclimate. Hydrate well even before you arrive and get after it once you get a good night's sleep. 4-5 days will not help you acclimate. Many say it gets worse if you wait 3-5 days. It is a great climb but the air gets thin the last thousand feet. Be careful on the way down....part of the road has cracks and humps that are jarring. Air down a bit before the descent. You can hit 50+ if you don't check your speed. I don't live far from there but I never managed to do it this year. I was mostly riding near Vail and Breckenridge (also great riding) but I will definitely do it a couple of times next summer. I have climbed on a road bike, a gravel bike, and a mountain bike. It is a great climb. The decent is best on fatter tires. Funny thing- one time I stopped on the descent and a big marmot waddled up over the side and came to me. I stayed still, and it looked at me for a good 5 seconds and then proceeded to start CHEWING on my front tire. My laughter did nothing to worry it so I had to yank the bike back a bit. It looked annoyed and waddled back down the mountain. If you're lucky, you will run into it.