Originally Posted by
Ritterview
As for the aero vs. rotating weight argument, theories are one thing and practice is another. If aero trumped everything, and rotating weight was negligible, then I'd expect that professional cyclists would use the same 60-80 mm rims on road races as they do on time trials. But, it seems that they favor rims of 45-60 mm on road races.
Road race, generally <60 mm
Time trial, >60 mm
True, on a road race the racers are often in the peleton, and thus are in a draft, which reduces the advantages of aero. However, since they end up having to add weight to their bike anyway to make the UCI 6.8 kg limit, if rotating mass was a negligible hindrance they'd just as soon add it to their rims, and gain some free aero advantage. But they don't. It must be, therefore, that the inertia of rim weight is
not negligible.
Accurately maneuvering and controlling a bike in a close packed group on even moderately windy days could also have something to do with it.
There is also no doubt that a lower inertia wheel feels significantly more lively but I think if you put the stop watch on it the maths will prove to be correct.