Originally Posted by
Carbonfiberboy
You may remember the tandem team we used to have on here composed of M-F track racers. Their tandem time on Mt. Diablo was the average of their single bike times. I don't know where you got the efficiencies for captain and stoker, but whereas a tandem (with the exception of BBs) has one of everything, 2 singles have 2 of everything. So I don't get that a tandem is less mechanically efficient than the sum of 2 singles. I do get that a team that isn't well synched will definitely suffer power losses. Even after lots of practice, we still don't climb well out of the saddle. OTOH, my stoker can't ride out of the saddle at all on her single. So we are definitely better on the tandem than on 2 singles.
the 7% power loss for the captain has been referenced on several previous BF threads. IIRC it comes from one or more studies. The explanation for the loss is the captain's power has to be transferred through 2 bb's and two chains to get to the hub. It's one of the arguments for making the stronger rider the stoker.
I didn't find the reference in a quick google search, but it's somewhere in BF archives.