Met Eric and Melinda for a ride up to the Baldy ski lifts. I took a little spin towards the Santa Fe Dam before they arrived at Encanto, and put in another 10 miles afterwards to get a total of 90 miles or more for the LAW century challenge. They consistently pulled away from me on the climbs up the face of GMR, but I was able to close the distance when the grade dropped a bit from time to time. Eric had a flat just before Cow Saddle and I did not see him. We regrouped just past the village, and Eric stormed by up the mountain; Melinda also pulled away and out of sight. But I caught Melinda and was right behind Eric at the entrance to the parking lot at the lifts. (The warming hut is remodeling, and they won't have Cokes for another couple of weeks.) Eric inspected his rear tire and booted a cut in the sidewall before we started back. More problems with the Di2 drivetrain: on Sierra Madre (on the way out) the chain dropped to the outside of the big chainring and wedged below the pin that is supposed to avoid that problem. At another time, the front derailleur "automatic trim" caused the chain to drop from the big to the small chainring when I shifted the rear derailleur (from the 25 to the 28 cog, I believe, on the 11-32 cassette). Also, there was at least 1x with a "partial" shift when going over a rough patch of blacktop with the chain beginning to shift to another cog and then going back; this has been a recurring phenomenon with the Ultegra derailleur, but is not nearly as dangerous to me as the dropping of the chain from the large chainring when I'm powering over a roller, etc. Over 51 minutes of stopped time? Where? 5 min on Sierra Madre - chain dropped to the outside and was wedged under the chainring pin 1 min: Baldy; regroup w/ Eric 23 min stopped at the lifts 3 min: Ice House regroup on descent 5 min: Baldy Post Office regroup & water 6:22: GRR regroup & pic 1 min: GRR/GMR regroup 4:18: Camp Williams regroup/water 2 min: Encanto after Baldy