Another steak thrown in the Pirahna tank.
Question: Has it be measured how much of the speed increase experienced with the addition of aero wheels is due to weight reduction vs. aerodynamics gain?
well…race wheels arent necesarly lighter than training wheels… often disc will be heavier than a good quality race wheels… compare a mavic ksyrium trainign set to a zipp 808 set… 100% of the gain are from aero… not lighter…
weight isnt important …
All of the answers you seek are here:
LOTs of information there…
look into the right column under tools; wheels/aero/weight…
the answer is yes. 10 years ago by John Cobb. Aero trumps weight at anything above 15 mph (he used to have a nice little chart comparing aerodynamics vs. potential energy aka weight savings). Old news.
Weight differences among wheels: The most accurate powermeter in existence can’t tell the difference in the power required to go a particular speed around a course.
Aero differences: Any powermeter can tell the difference, easily.
There is an order of magnitude difference.
the answer is yes. 10 years ago by John Cobb. Aero trumps weight at anything above 15 mph (he used to have a nice little chart comparing aerodynamics vs. potential energy aka weight savings). Old news.
BOLLOCKS! Aero does not trump weight. YES is general, BUT if you take two wheel sets, exactly the same hubs and rim shape, but one pair has rims that weigh 900g, versus the other that weigh 400g - the lighter set is faster, hence aero does not always trump weight…QED
The answer is depends. If you get an absolute pig of a pair of aeros, the lighter training wheels MAY be better. IF you get the main brands, you should be fine and faster. BUT, you should buy an aero helmet first - MORE BANG FOR YOUR BUCK!
the answer is yes. 10 years ago by John Cobb. Aero trumps weight at anything above 15 mph (he used to have a nice little chart comparing aerodynamics vs. potential energy aka weight savings). Old news.
BOLLOCKS! Aero does not trump weight. YES is general, BUT if you take two wheel sets, exactly the same hubs and rim shape, but one pair has rims that weigh 900g, versus the other that weigh 400g - the lighter set is faster, hence aero does not always trump weight…QED
Weight only matters when accelerating. On a flat course at steady speed, there is no difference in power required between your two example wheels.
Do the math.
Although it’s already been beat to death here, I’ll just note that the exception is a pure hill climb. If you’re doing a hill climb TT there comes a point (if it’s steep enough) where wieght becomes more important that aero; you can also see that with the analytic cycling calculators.
Thanks!
Yep, generally it’s right around 10% gradient, where weight will begin to trump aero, OTHERWISE, for anything less than 10%, AERO ALWAYS WINS.
In a recent podcast on “tri-talk” (can’t remember which one) the presenter looked at a set studies that suggested aero does trump lightness in all but uphill bike sections - I mean that you literally need to have a solidly uphill bike leg to make light wheels instead of aero wheels worthwhile. If I remember correctly in the Alpe d’Huez TT in the TdF a few years ago, most have aero wheels.
BOLLOCKS! Aero does not trump weight. YES is general, BUT if you take two wheel sets, exactly the same hubs and rim shape, but one pair has rims that weigh 900g, versus the other that weigh 400g - the lighter set is faster, hence aero does not always trump weight.......QED
Wait, re-read what you just wrote. You appear to have said that if you have two wheels that are aerodynamically identical, the lighter one will be faster. Now, as others have pointed out, that difference may not be measurable, but it exists. So OK, all else equal, a lighter wheel is faster. Now imagine that one of the wheels is slightly more aerodynamic. The magnitude of the effect of reduced aerodynamic drag is so much greater than that of reduced weight that for all practical applications (eg. riding your bike in a triathlon) the more aero wheel will always be faster.
The situation changes, a little, when you are riding a significant net uphill. So if you get out of the water at the bottom of Alpe d’Huez and start running at the top, you may want to consider a light wheelset over an aero one. However, if you have to ride back down before you start running, an aero wheel comes out on top again.
To the OP: .5% of the speed increase comes from weight, 99.5% from aerodynamic improvement. Roughly 
I would think some combination of speed and gradient would need to be considered. For example, 9% grade slowly (5mph- think unfit, like me) would be way different than 11% at some crazy TDF like speed (10+mph). I think 10% might be a good rule for the seriously fit athlete assuming that translates into a smallish window of speed at 10%. For slower people, I’d think even 5% might be better with weight than aero, by a long shot.
Depends on course, but I bet gradient is only a factor of many, just like speed is not the only one either. OK, I guess it’s a combination of only those two… maybe a windy day matters too
The statement that a heavy set of wheels, with the same aerodynamics as a light pair, run at the same speed is incorrect. NO race route is flat, so inclines, slight or otherwise impact the rider. IF you ride with power, you can see the changes.
To the OP: it appears everyone wants you to buy a heavy aero set of wheels. I say buy aero, and buy them light as possible within budget.