Fun & Fitness over 50

Sunday was "long" ride day. From the house out along the Mohawk-Hudson bike trail 28 miles and back. A total of 56 miles. In the rain. I've been looking forward to a rainy day long ride 'cause I know those charity rides I'm doing in June are going to go on rain or shine so I want to be prepared. I know I can do it but you don't know until you DO it. It wasn't a downpour but a pretty steady moderate rain. Everything went well. The bike running good. I was concerned about a wobble in the rear wheel and that it might be hitting the brake pad but it didn't seem to be a problem. Also on my last ride I noticed that my achilles tendon was bothering me at about mile 35. I had just changed out the original, hard Raleigh seat with a comfort seat and was wondering if that was causing the problem somehow. I changed the seat to a firmer sport seat that came stock on my Trek 4100 MTB and didn't have any problem on this ride. I was also trying to ride more out of the saddle and shifting back on the saddle on hills to "recruit the glutes".
This was a fantastic ride. I felt great. I nibbled on the Clif bars a little bit a time and that may have helped keep my energy up. No fatigue at all.
There's a stretch on the trail where for several miles it is flat, maybe a slight grade, I can't tell, but I get in a groove, 90 rpm or thereabouts, 75%MHR and I feel like I could go forever. Rain doesn't matter. Really hate to stop to take a bite of Clif bar. Just want to keep goin'.
Like being locked in on some tractor beam. You and the bike and the trail. All one thing. Effortless. Locked in on a beam.