I'm in the NYCC, which has around 2,000 members. As you well know, clubs of that size will have a full range of riders of varying abilities. I've seen riders on "B18," and even some "A" rides, stretch out far more than 30 seconds on very short climbs -- usually as I'm passing 3/4 of them on my 26+ pound bike, by the way.
That said, as best I can determine 5 extra pounds on the bike will cost you about 1 watt on the flats and 2 on a steep (7%) climb.
Your ability to produce power will vary at least that much on an average day anyway, yes? Not to mention that your body weight will vary by a few pounds from day to day, too.
Meanwhile, riding in the drops instead of the tops will save you 40 watts on the flats, assuming you don't lose the ability to generate power due to the position. And if you switch to wheels that are heavier but more aerodynamic, you'll have a net benefit unless you're you're climbing Monte Zoncolan all day long at 6 mph.
What can I say, it merely seems obvious to me that numerous other factors -- particuarly aerodynamics, rolling resistance, rider fitness, and environmental factors -- have substantially greater influence on your performance than weight. I can see how the small amounts might be critical in a race but on a club ride? Even a fast one? Seems unlikely. You'd have to already be pushing your limits if you're OTB du to a 1-2 watt difference.
Ergo, if you're getting smoked on the Gimbels ride, 5 extra pounds on the bike isn't a reason... it's an excuse.
