FSA KFX i28 Wheel Review
Let’s take a moment to appreciate spandex. Yes, spandex—the stretchy fabric that’s been the subject of jokes, debates, and countless fitness videos on VHS.
Born from wartime rubber rationing in the 1950s, this stretchy fabric revolutionized cycling by pushing out traditional materials like cotton and wool. In many ways, the FSA KFX i28 wheelset is the spandex of the mountain bike world; it’s lightweight, performance-oriented, and challenges assumptions about what the cross-country realm is capable of handling.
At 1,565 grams and sporting a modern 28-millimeter internal rim width, the KFX i28 straddles the line between pure cross-country race weapon and trail-capable performer. As cross-country courses have evolved to include more technical features, these wheels aim to meet the demands of both racing and aggressive trail riding—a tall order for any wheelset.
The technical specifications tell a promising story. The set’s carbon fiber rims feature a tubeless-ready, hookless bead design that demonstrates impressive durability in testing. An asymmetrical rim profile balances spoke tension, while 28 double-butted, straight-pull spokes in a two-cross pattern provide a lively-yet-stable ride characteristic. The design choices suggest FSA focused on creating a wheel that’s not just race-day fast, but training-ride tough.
A closer look at the rim construction reveals some clever engineering. FSA incorporated turrets at each spoke insertion point—a design feature that might look like architectural flair but serves a distinctly practical purpose. These reinforced anchor points for the nipples help create a rim that maintains its structural integrity while keeping the grams down.
At the heart of these wheels lies a 72-tooth ratchet hub design that provides quick engagement for technical terrain. The CNC-machined aluminum hub shells kept things running smoothly through multiple wet rides and dusty conditions, suggesting adequate weatherproofing and quality bearing choice. The freehub produces a balanced sound—present enough to let you know it’s working but not so loud that it’ll scare the local wildlife. It’s a small detail, but one that riders spending long hours in the saddle will appreciate.
On-trail testing revealed that these wheels live up to their racing pedigree while offering surprising capability beyond the start line. The lightweight construction provides the expected snappy feel on climbs and maintains momentum efficiently across rolling terrain. But it’s the wheels’ composure in technical terrain that raised my eyebrows. When paired with modern 2.4-inch tires, the KFX i28s maintain stability through rock gardens and offer enough confidence to push hard into corners—territory I often reserve for burlier wheels.
Multiple test rides across varying terrain demonstrated the wheels’ versatility. The rim width provides excellent tire support, allowing for lower pressures without the squirm typically associated with narrower cross-country rims. Power transfer feels immediate—when you stomp on the pedals, these wheels respond instantly. While they exhibit noticeable stiffness under power, they avoid the harsh feedback often noticed by discerning riders in some lightweight carbon hoop offerings. Through tight switchbacks and technical climbs, the quick engagement of the hub makes a noticeable difference in maintaining momentum and clearing obstacles.
Durability concerns often come up when discussing wheels, but FSA appears to have addressed this through several design choices. The hookless bead construction proved highly resistant to impacts, while the decision to use brass nipples rather than aluminum suggests a focus on long-term reliability over marginal weight savings. After extensive testing, including several direct rock impacts and many less-than-graceful landings, the wheels remained true and showed no signs of structural compromise.
This focus on durability extends to the hub internals as well. A detailed inspection reveals the same attention to detail found in the rim design—each component, from the precisely machined ratchets to the robust springs and freehub body, shows signs of careful engineering and production. While long-term durability can only be proven through time, the quality seen here suggests these hubs are built for the long haul.
The FSA KFX i28 wheelset represents a new generation of cross-country wheels that refuse to be pigeonholed into a single category. Much like how spandex transcended its original purpose to become a symbol of cycling performance, these wheels push beyond traditional racecourse boundaries. They bring together precision handling, rapid acceleration, and notable durability in a package that made me reconsider what’s possible from a lightweight wheelset.
For riders seeking wheels that can handle both race day and aggressive trail riding, the KFX i28s present a compelling option. While their low-key looks might not turn heads quite like your vintage lycra collection, they’ll certainly make you question whether you need separate wheelsets for racing and rowdy weekend rides.
MSRP: $1,617
Learn more: https://shop.fullspeedahead.com/en/wheelsets/mtb/kfx-i25-wheelset
