UPDATED 3/1/15: Ride the Rockies just posted the following update to the route elevation gain numbers on the RTR Facebook page:
For those on the fence about applying for this year's ride due to the elevation profiles, please note the updated data we are now able to report having just returned from a route recon / community trip where we met with local PD, CSP and CDOT: Day 1 - 2,952 ft., Day 2 - 8,000 ft., Day 3 - 5,583 ft., Day 4 - 1,458 ft. and Day 7 - 4,511 ft. We will not be able to provide data for Day 5 and Day 6 until later this spring due to road / pass closures. This data captured on our own Garmin suggests these stages will equal 4,700 ft. less of climbing than previously reported. Registration closes today at 5PM MST. Best of luck in the lottery - hope to see you this June! www.ridetherockies.com
Based on what I know about Day 6 from Salida to Canyon City (see below), you can take off another 3,000 feet, bringing the approximate elevation gain down to around 33,000!
To their credit, I learned about the overestimation from a post on the RTR Facebook page. The reason for the error became clear when the ride organizers explained that they used MapMyRide to chart the course and estimate the elevation gain (MapMyRide is notoriously bad at estimating elevation gain).
So the good news is that the 40,000+ estimate could be at least 5,000 feet too high. That's a lot better than last year when RTR underestimated the elevation gain by the same amount! That's right, this is not the first time the estimates have been off. Last year they estimated the route at 28,000 and it ended up being more than 33,000! That was just painful.
The bad news is RTR staff have said they won't correct the numbers until early May after they ride the course with GPS devices. Until then, your guess is as good as mine.