He blamed the wheel breakages on a combination of rim brakes and over tensioning of spokes. He also said that if he was doing something like this again, he'd use disc brakes.Unlikely. If the stresses from rim brakes were the cause of broken spokes - the front ones would break also (most of the braking in extreme stops is on the front)
+1. Disc brakes put a lot more stress on spokes.
About the spoke-bracing angle though-- that makes the wheel a lot
stronger, and is why tandem wheels are so much stronger, and famous wheel builder Peter White
insists that 36 spokes are virtually always enough for a tandem when the wheel is built right. I found out about him on the tandem forum where everyone raved about his trouble-free 36-spoke tandem wheels, including for loaded touring. To get that wider spoke bracing angle though, tandem wheels use 145mm or 160mm dropout spacing, not 130 like road bikes'; so you can't just put a tandem rear wheel in a single road bike or even a touring bike. Decades ago when tandems' rear dropout spacing was 135 or less, they had a lot more wheel trouble even with 40 or 48 spokes. To further press the point about bracing angle: For the last 9 years, Santana has been selling 16-spoke tandem wheels which have proven to be very reliable. The dropout spacing is 160mm, and the spokes from the right flange go to the left side of the rim, and vice-versa, to improve the spoke bracing angle.
The inertial weight advantage [of the smaller 26" wheel] will be very slight as the smaller diameter wheel also has accelerate faster to reach the same road speed.
No, it's the same number of feet per second. RPM itself is not the issue. The myth of rotational weight is exploded in this
wheel-science web page though. You can see for example in the middle of the first table that the wattage savings in the uphill portion of a training ride if you cut the front wheel's rotational inertia in half
(an absolutely huge
reduction!) is only 0.004%. IOW, it doesn't matter.
The very low hub rolling resistance will be slightly higher for the smaller wheel at any given speed
very low, yes-- totally negligible.
and the smooth surface rolling resistance of the tires (assuming identical construction) should be identical.
It's a hair higher with the smaller tire, due to more energy being wasted by the slightly sharper bend at edges of the contact patch; but yes, the difference is too small to matter.