Speed of whom? It's all over the place, depending on who we are and what we do. In my last 50s, I was averaging 18 on 60 mile rides in 50'/mile terrain. I haven't been out on my single this year, but I'm probably at about 16. Last Sunday we averaged 14.5 on our tandem, similar hilly terrain. Oh - as most of you know, I'm 76, my wife 72. I'm not talented, I just ride as much as I can. My best time on a 400k in my early 60s came out to 16.66 including stops. Only 6600' though.
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Results matter