I'm finding in these cooler winter temperatures (50 degF or so) that I can sustain high 140's fairly comfortably (I'm mid-60's) when climbing. As the temperature warms I'm more like a low 140's guy. It make's sense that this is simply the effect of having to cool my 200 lbs. Just looking to see if this is consistent with others' experience.
I've not seen over 158 in the last three years of cycling, have never done a max HR test and don't feel the need. My wife and I are recreational tandem riders, mostly 100K and 100mi organized rides. FWIW my resting HR is mid 40's.