Originally Posted by
ThermionicScott
Sure they were! It was a major reason that the cycling market pivoted from road bikes in the 1970s to MTBs in the 1980s. Those hard skinny tires. The difference now is that the effect is finally being quantified and it's not seen as "un-manly" to discuss comfort on the bike.
I think that as recent as this century's first decade, the hard skinny tires were indeed that.. ie. 23mm or less tires that were inflated to 120psi (or more) was very common
Originally Posted by
HTupolev
If a lack of compliance is resulting in discomfort, the energy being spent making you uncomfortable is coming out of your forward momentum. Even ignoring the performance affects of being fatigued, pumping tires comfortably isn't just about comfort for the sake of comfort.
Where are you getting those numbers? A 160lb road rider tends to me somewhere in the ballpark of a 180lb bike+rider. If we assume a 55/45 weight distribution, that's about 100lbs on the rear wheel and 80lbs on the front. If we target 15% drop by referencing the Berto chart for a 25mm tire, that's a little under 90PSI for the rear wheel and a little under 70PSI for the front wheel.
15% drop was never "proper", it was a rough rule of thumb to establish a starting point. Obviously some folks treated it like a hard rule, but that's not much different to how the same happens with any rule of thumb, like some people think that every bike should have the fore-aft set to exactly KOPS.
I don't disagree with the notion of comfort/fatigue eventually factoring into performance on longer rides. I think though that what I've noticed is that evidently many riders were always fatigued and beat up by their bike tires before the more recent notion to go wide and soft. For some reason though, it seems we're only hearing a lot about this now, because even a few short years ago, I don't recall as many talking about it.
FYI, I typically use the dorkypants calculator (the middle one on the linked page below). As a starting point, for myself I use the 45/55 result to set my front tire pressure and the 40/60 result to set my rear tire pressure. However, I do generally adjust to fit within tire sidewall ratings (example: calculator gives me 78psi front result at 45/55 for 25mm tire but my 25mm sidewalls indicate 100psi as minimum -- admittedly I do cheat a bit lower than this though.)
Bicycle tire pressure calculator