The other day I was approaching an inline skater in full kit who was moving right along. I know nothing of inline skating and almost never see them where I ride, but this guy was doing an honest 20 mph -- good pavement, flat to very slight downhill. I slowly caught up to him and passed, we both nodded. A minute of so later, he was on my tail and asked if he might draft for a while -- I said "sure."
I looked at my speedo and I was at 22-23, which is pretty fast for me. He was right there with me and hung on for several miles. We were approaching a 1-mile stretch that I have marked as a stretch I run harder. I told him that was coming and he said "do whatever you need to do." Okay then.
I took it to 26-27 and still he was with me. About 2/3 of the way through the mile, I just had to know whether I had any chance of dropping him (or if he was going to drop me!). He fell off at about 28, but hokey smokes, I was impressed!
Again, I have no idea whether this guy was typical for a serious skaterl, but it was fun and he was polite to boot.