The ride started off well, although it is necessary to pay attention if keeping up near the front as a "peleton" forms behind the pace car and not everyone is giving due care to riding a consistent line. I had an odd mechanical problem an hour into the ride (at mile 21.5) when my chain came off to the outside of my big chain ring and wedged in against the crank. I cut my index finger trying to tug it out, and fortunately a couple of old timers in a SAG vehicle came by and took over for me. It looks like I was only waylaid for a little over 7 minutes, but it felt a lot longer as the group I had hoped to work with were long gone, and many riders passed me by. Rode solo much of the time, basically after getting to the climb up Geysers Rd. at mile 74. However, notwithstanding having lost the group with which I had hoped to ride, I did get into a reasonable pace line for the nearly 40 miles of relative flat riding in Napa County after descending from the Trinity climb (ending with the climb up Geyers Rd), averaging just over 20 mph. (A smaller, slower group after the rest stop at mile 53.6.) Before lunch, I only had 5 min of stopped time, not including the 7 min. for the chain mechanical; an avg. of 16.5 mph for 110 mi & 8200' of elevation gain. 20.5 min stopped at Geyserville lunch stop on Skaggs Srings Rd; it appears that the temperature went up about 10°F there; I wanted to leave more quickly, but I felt I was low on calories and drank 2 cokes and had some sandwich meat and cheese. A good athletic tube-sock with ice around the neck is needed here. I did not do too badly with the heat, and I took LOTS of Endurolytes, but I should probably have had some of my cal-mag supplements as I felt the hints of leg cramps on The Wall and the climb up from Ft. Ross. I still had leg strength but it felt like I had to spin easy to avoid serious cramping. The bigger problem was I felt a little bonkish, too. I was able to peddle at a reasonable speed on the flats, but I was not able to power over rollers on CA-1. So, following the lunch stop, there was 90 miles and 9700' of elevation gain, and I managed an average of only 12.5 mph and had a whopping 31 min. of additional stopped time! When climbing on the first half, my avg heart rate was consistently around 155 bpm on both Trinity and Geyers Rd, but dropped to 145 on the first part of Skaggs, and 135 on the second part. 145 bpm on the segment of my best effort on "The Wall", but I started looking for the outside of the ramps on curves there, a practice I continued on the climb from Ft. Ross. My avg. pulse was more like 135 bpm on the climb from Ft. Ross; I even resorted to walking a couple of particularly steep pitches, and doing some serpentine climbing. Clearly I was losing the ability to sustain power later in the ride. I don't know how much of that I can blame on "de-training", with only having a couple of rides in the preceding 3 weeks following the Eastern Sierra Double (short and easy on June 1, and the Son of Death route unsupported the week before, which kicked my butt). (See: http://www.cyclingweekly.co.uk/fitness/training/detraining-the-truth-about-losing-fitness-22330) I did not start my Garmin until 0.37 miles after the start. I have saved many "segments" of the ride for ease of reference of different sections of the ride, and the location of some of the rest stops. (Scroll down the left panel of the screen.) I suggest that care should be given to coordinate with the core members of a suitable pace line to get in and out of the rest stop in Calistoga together.