There was a time when house-branded components were only cheap stems, handlebars, and seatposts with a logo slapped on to keep the bike's price as low as possible. These days, they're often high-end carbon fiber wheels and handlebars that, while still being used to save some coin over name-brand stuff, are often worthy of upgrading to themselves. Santa Cruz's Reserve wheel range debuted in 2017 and would probably fall into that category for most riders, and they've just released a new rim size for those who like big wheels and big meat: a 29" version of their Reserve 37 rim that's, you guessed it, 37mm wide internally.
The Reserve 37 rim is intended to be used with tires from 2.5" to 3.0" wide.
Rims this wide tend to splay a tire's bead out, which can, in turn, flatten the profile and make the handling a bit funny if the tire wasn't designed for it. Santa Cruz says that the 37mm internal width is intended for rubber that's 2.5" to 2.8" wide, and they'll even play nice with your 29" x 3" wide tires, you lovable kook.
The carbon rim is constructed in the same way as its 27.5" counterpart, and that means they get the same asymmetrical drilling and external butting at each spoke hole. The offset holes are used so left and right-side spoke tension is closer to being equal, while the extra material at each of the angled holes is said to increase strength in a critical zone. The bumps make the Reserve hoops stand out from a sea of black carbon rims that all look alike, too.
There's added carbon at the spoke holes (left) for increased strength at a critical spot, while the bead (right) is said to be relatively thick for impact resistance.
Complete wheels are built with twenty-eight Sapim CX-Ray spokes, with the idea being to add in a touch of compliance by using fewer (and bladed) spokes, and you can get 'em with DT Swiss' 350 or Industry Nine hubs at the center. There are, of course, SRAM or Shimano-style freehub options.
Time for the numbers. A bare, 29" Reserve 37 rim sells for $599 USD and is said to weigh 495-grams, while a complete wheelset with the Swiss' hubs will cost $1,599 USD and weigh a claimed 1,785-grams. They do come with a solid sounding warranty as well, with a free replacement rim if you manage to inflict fatal damage while riding. Off-bike incidents fall under the crash replacement program.