Originally Posted by
merlinextraligh
Wheels make up about 10 to 15% of the aerodynamic drag. Going from a conventional 36 spoke wheel to a deep dish low spoke carbon wheel can reduce that 25% or about a 2-3% decrease in the total aerodynamic drag of bike and rider.
The wheels when looked at by themselves, yes...
On a single bike with a physically-fit, average size test subject (usually a licensed racer), again I would agree.
However, not so for a tandem that has 1.5x as much aero drag as a single bike. Moreover, unless both riders fall into that physically fit, average size model the entire marketing spin on total bike/rider aero drag reduction is substantially less for a tandem if only because the total aero drag number is substantially higher to begin with.
There's no question light weight wheels feel much more lively and faster and that they can provide a tad improvement in performance (~.02% rotating mass and some equally low % of aero drag reduction) but, again, other aspects of performance change such as reduced rolling resistance typically comes from other changes that are made at the same time, e.g., tires. Moreover, to really reap the moderate reductions in aero drag a team really needs to be pushing their tandem at the higher speeds where aero drag becomes large enough to yield those more tangible reductions.
The only reason I could ever recommend something like racing wheels for a tandem that's not being used for racing is: (a) they look racy, (b) they feel more lively, (c) they're typically lighter than most conventional wheels, (d) they provide a huge placebo effect that can make your team train and ride harder or more often, and (e) you have the cash on hand to buy them as a second set of wheels.