If you are still on the fence about getting carbon mountain bike wheels, questioning their strength and durability, the Santa Cruz Reserve 25 29in i9 Boost Wheelset is here to convince you that your doubts are unfounded. All Santa Cruz rims are reinforced at critical failure points versus traditional carbon rims, letting you consistently rally through the hardest lines without the wheels so much as flinching. Santa Cruz was careful in designing these carbon wheels wanting them to be the strongest on the market, and totaling redesigning the impact testing methods used on lesser carbon rims in the R&D of their Reserve Wheelset. Replicating pothole-like impact test is fine for road wheels but Santa Cruz goes a step further developing their own testing procedure that simulates one-sided impacts that can occur when pin balling through a burly rock garden. As they tested other carbon wheels, it became readily apparent that most carbon wheels not only broke on the affected bead hook, they also failed at nipple and rim interface caused by drastic changes in spoke tension as the wheel flexed on impact. To mitigate these breakage issues, Santa Cruz beefed up the bead hook, increasing the thickness by one millimeter along each side for improved resiliency. The engineers then sought to fortified the spoke holes with square-shaped reinforcements you can see externally on the spoke face protecting the nipples from suddenly pulling through on hard impact. Santa Cruz is so confident in the strength of these wheels, it offers up a lifetime warranty. This particular Reserve 25 Wheelset is laced to Industry Nine Torch Hubs with near-instantaneous 3-degree engagement which is an absolute godsend climbing technical terrain. The rims are 25-millimeters internally, maintaining an optimal tire profile when you're running rubber in the range of 2. 0 to 2. 4in. J-bend spokes and mechanical locking nipples make for easier replacement, should you break a spoke or nipple when you're t...