2014 Bike Sebring Data
Larry, if it is helpful here is my 2014 Bike Sebring data. Same data but posted originally to RWGPS and then later to Strava. The elevation data should be pretty good as I was using my RFLKT+.
You will want good lighting if you do the 24 hour as the track is not lit. Pay particular attention to light characteristics that will let you corner well at night on relatively tight corners. You will want a light for the start on the track, especially if you start fast out of the gate. It will quickly become light enough to not need it but the start will be dark enough to require good lighting. Plan on a way to turn the head light off as soon as desired to preserve battery for later if you are going to do the 24 hour. The start can be tricky due to bunching, darkness, and a lot of varying take off speeds.
Battery management to power lights and other electronics for a 24 hour run can be a bit tricky. I had 2 batteries for my front light and had to switch during the night track period. It was a bit problematic as the light didn't fade and give me warning but basically just went out. Fortunately I was pretty close to the pits at the time and only rode a short distance before I could get to the pits and change my battery. I was not carrying the spare with me but probably should have in case it had done this far from the pits and my other backup gear.
I used an iPhone 5 with Cyclemeter and my Anker Astro 5600mAh external battery connected to my iPhone. This was only good for about 18 hours. I've since switched to using an Anker E3 10000mAh for 24 hour stuff but it is much larger and heavier, but easily powers my phone with display on constantly with GPS, etc for well over 24 hours.
Consider using the same technique that race cars use to "straighten corners" to minimize the total travel distance to get all the way around the track. I saw a lot of riders keeping a consistent distance from the track edge rather than trying to cut the corners and minimize travel. Over a long period the little bit of extra time circling wide around the track can add up.
The track is pretty wide but it can get crowded with enough riders. There are also seams and other bits that can be hazardous.
Some people were trying to bunch up at the timing gates on the night track portion which is bad both for timing and safety. People got better at not bunching up here as the night went on.
There are some fairly rough sections of road out toward the lake on the long loop and grit/sand/dirt in many of the corners so you'll need to keep an eye on the surface and your speed.
If you are doing the 24 hour non-drafting (RAAM qualifier) you will also want to watch out for pelotons passing you. Some of them can get quite long and box you in a bit closer to the shoulder than you want to be. I got caught by a big one at the start that kind of annoyed me because they came up behind me just before I started picking up speed and I got stuck until they all went past me.
Be careful of vehicle traffic too, they are normally really good around there from what I've seen but there have also been some bad incidents the last couple of years.
It has been very, very windy these last two years that I was there. Gusts up to 30+mph and steady winds in the 20+mph for long periods. This can pose handling dangers, especially with disk wheels but more importantly it can get cold enough to create some hypothermia risks if you aren't properly prepared - or get behind on nutrition even if you had proper gear. I think that is part of what I struggled with back in Feb. This year was better, the winds died down in the late afternoon, early evening but two years ago it blowed strongly all night long and got down to around 38F or 39F. Frankly, I don't know how Maria did it that year. This year I think the lowest temp was maybe 40F or 41F but without the high wind. Daytime high on race day was around 68F if I recall correctly with a smallish rain shower that mostly caught the slower riders. The day before race day was gorgeous.
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RWGPS
http://ridewithgps.com/trips/2245489
11 mile loop practice run from the day before. This is typically where you will feel the wind the most as you will be fighting the wind at first half of the loop and having it mostly at you back for the second half. The other part that hurts is the final return leg from the long loop back to the track as this is almost head-on into the wind.
http://ridewithgps.com/trips/2239114
Strava
http://www.strava.com/activities/114918229??
-Eric