Originally Posted by celticfrost

IMO, here's the 2 hardest parts of the ride:

1. The elevation/ lack of oxygen at altitude -- lowest elevation is around 7,500', highest is 11,990. That calls for some really good aerobic conditioning and/ or acclimating to those elevations.

2. It looks like the 1st 14 miles averages around 4.5% grade. But, for most people (i.e. me ) it takes a good 30-45 minutes to warm up the legs (engine) before I'm able to hit the climbs very hard. Without a bit of warm-up, those 1st 14 miles can break you.