Just back from St. George, Utah after one of the toughest rides I've ever done. Here's the link to the 2014 webcast: Webcast 2014
When I first contacted Deborah Bowling (the race organizer) about riding this on a fixie, she said "it's not something we would recommend." But, being a contrarian, a fixed gear rider, and a believer in "ride what you've got" rather than "carefully select the correct bike for the application," I couldn't resist entering this 520-mile race.
Having finished it, and having taken longer than what I would have liked for a finishing time, I can only agree with Deborah. I wouldn't recommend that you ride this on a fixie. However, I did leave a very generous time allowance for those wishing to attempt this enterprise and take the record.
My time estimate is based on my standard rule of thumb for solo rides: 25 kmh plus 1 hour for every 1,000 meters of climbing. For an 836-km race with 10,000 meters of climbing, this would work out to about 33 hours + 10 hours, and indeed, I finished in just under 43 hours. I had wanted to at least crack 40 hours, if not 36 (the overall solo winner took just over 36 hours), but the two major climbs were just too long and too steep to keep a good rhythm on a fixie. Plus there were more than just those two major climbs (Boulder Mtn and Cedar Breaks). There was also the steep sucker before Escalante, the steep sucker before Boulder (city), that long, straight, never-ending flat section of unfinished chipseal before Loa, that long, straight, never-ending climb up to 8400 feet out of Loa, and a bunch of other sections that became insane, especially after light hallucinations started to emerge after about 40 hours on the bike with maybe three 15-minute power naps along the way.
But it was a worthwhile learning experience, and I now hold the fixed gear record for the Hoodoo 500! Oh, and I was also the oldest rider as well as the first 60+ solo rider (2 others were entered, and they were pretty formidable competition - one of them was Dave Elsberry, who had ridden RAAM earlier this year, but I think he had some stomach issues).