Trail wheels often fall into two categories—they’re either heavy and durable or light and flexy. And because of this, a lightweight, wide-profile, and enduro-ready carbon wheel seems like something only found in a fairytale, but lucky for you, we made it a reality. The Traverse SL Fattie 27.5 puts all the flick'able, nimble features you need in an all-mountain wheel into one package, and it has the results to prove it. Along with light overall weight, stiffness, and durability, another top priority for the Traverse SL was ease of use. First off, we got rid of the creaky straight-pull spokes and corrosion-prone alloy nipples. Next up, we landed on 28 J-bend spokes, for both the front and rear wheels, that are all the same length—making it easy to find replacements if needed. And finally, we engineered a new hub design, with a wider profile and higher flange to aid in overall stiffness. What's with the big-boned name, you ask? The Traverse SL Fatties may be wide, but with a 30mm inner rim width, they’re far from the girth of a fat bike rim. But let's talk width. You've probably noticed that mountain bike rim widths have hovered between 19 and 23 millimeters for decades, and they've been long overdue for a change. In the search for a better wheel design, our engineers began testing 2.3- to 2.5-inch tires on 45-millimeter-wide fat bike rims to see what, if any, benefits could be found. It only took them a few rides to realize that the wider rims offered a variety of advantages, like adding additional tire volume, which better supports the tires in hard cornering, greatly improves traction because of the ability to run lower pressures, and noticeably increases rim stiffness. They did note that there is an occurrence of diminishing returns with increasing width, however, and after testing everything from 25 to 45mm, determined that a 30mm inner width is optimal. After determining the width, we began designing the rim using the knowledge that we gained when deve