Originally Posted by
alan s
For ordinary commuting on an MTB with wider tires, 26" wheels are better. Unless you are spending top dollar on the lightest, fastest tubeless 29" wheels/tires, the average 26" wheel, tube and tire combo will weigh substantially less and outperform the 29". If you really want to commute faster, get a light road bike with skinny tires. And get in better shape.
Is this based on tests?
FWIW there was a debate long ago on which was better for tandem use, 700c or 26" wheels. The results after some testing were that the 700c wheels performed better and it came down to the longer contact patch that the bigger wheel provides.