Stan's ZTR Alpine Disc Rim has a shape that is based on their previous lightweight champion, the ZTR Olympic, yet the Alpine is lighter. The ZTR Alpine Rim is designed for those who need the lightest possible rim for racing. And like the name implies, climbing with a superlight rim such as this makes you long for extended sufferfests high in the mountains. Compared to the ZTR Crest, it's 1mm narrower at 20mm inside and 10 grams lighter.
As Stan's No Tubes continues to improve their BST, or bead socket technology, their rim weights continue to plummet. On the Alpine, the bead hook is nearly imperceptible and the sidewalls are just tall enough to allow a seal with the bead of the tire. As they trim the fat from the outer portion of the rim -- the sidewall and bead hook, they can add material as needed to the wall thickness to ensure that the ZTR Alpine is strong enough for racing, yet light enough to satisfy the nitpicking weight weenies.
The shorter BST sidewalls are stronger, more ding resistant, and lighter. The inside of the rim is perfectly matched to the bead seat diameter of a 26" tire. This makes the tubeless seal a good one, though the tires will be a very tight fit on the rim. In our experience, a set of thin but flat levers works best for installing/removing the tires. To make them tubeless you'll use Stan's yellow tubeless tape and one of their tubeless valve stems or one cut from an old inner tube. Stan's BST tubeless system creates tubeless seals that burp less, leaving you with more air inside your tire and not on your mind.
Stan's ZTR Alpine Disc Rim is anodized Black or powdercoated White with red decals and is available with 28 and 32 hole spoke drillings. The 17.5mm deep, V-shaped rim is pinned, welded, and machined at the joint for a true sidewall. They will work with or without tubes. If you're building your own wheels, you'll need to know that they have a 536mm ERD. The claimed weight is 330g.