Is a 16 grams CO2 cartridge enough to inflate a 29" mountainbike I used to ride a 26" mtb, but now I'm switching to a 29er. Since the volume of the tire increases, I was wondering is one 16 gram CO2 cartridge enough to inflate the tire? _Notes:_ The tire will be between 2.1 and 2.25 wide. Since I'm big (110 kg) I need more pressure than a lower-weight rider.

Yes. One 16 gram cartridge is enough to fill an average 29" tire. I just tested in my Schwalbe Rocket Ron 29x2.25, and from empty it gets to about 38 psi. I run tubeless, so normal pressure at my 110kg weight is around 35-38psi.

With a tubed setup, 38psi might be a touch low, but plenty to get you back in off the trail.