Whenever I ride with a group, I always size up the strong riders at the beginning of the ride. I can normally pick them out- for the most part. At the beginning of each ride I normally "sit-in" and warm up and conserve energy because I know I'm going to be pulling (out front) for at least 1/2 the ride. Last nights ride was 1.5 hrs. long with approximately 1 hour of steady riding. The other 1/2 hr. is spent walking over bridges, stopping, slowing, etc. Of that 1 hour steady riding, I'd say I'm riding in the L3/L4 (sweet spot) zone and L4 (threshold) zone. When one of the strong riders pass me and go out front and try to separate themselves from the pack, I'm the first one on their wheel. I don't like anyone getting away. That's what happened last night on the PA side of the ride. I was out front pulling at 16.5 mph and one of the strong riders passed me, so I jumped on his wheel. We were now averaging 17.5 mph. BTW, riding at 16.5 mph on a heavy mountain bike on the mud/gravel is probably equivalent to riding at 22 mph on a light road bike on asphalt. You can see from the graph below, I wasn't utilizing any more power and my heart rate didn't increase any more than when I was going 16.5 mph pulling out front vs. drafting at 17.5 mph. Ahh, the beauty of the draft.
On the NJ side of the ride, the same thing happened. Except the guy that passed me was sitting in the back for 3/4 of the ride. i.e. conserving energy. That kind of pissed me off. The guy doesn't share in any of the pulling, and then when everyone else is tired, he pulls away and separates himself from the pack. I tried to reel the guy in by myself but every time I got close he pulled away. I tried to recruit the guy behind me to help me pull and reel him in but the guy just didn't have enough gas left in the tank. That's when two more riders a strong woman rider (Nora) and some other guy got in front of me and we chased him down. You can see we were averaging 18+ mph at the end of the ride. We came within 50 yds. of the guy when we finished. It was fun chasing him down. I know he knew we were gaining on him. At the end of the ride, I saw the guy in the parking lot (he was an older guy like me) and I told him, "we almost got you, good riding". He smiled, he knew we almost caught him at the finish. I was still kind of pissed that he sat in for 3/4 of the ride though and then when everyone was tired he decides to break-away. Here's the graph of the final chase:
Anyway, if you want to know (one of the reasons) why I ride, that's why. Good Fun!