The Mtbr crew previewed the new Specialized Stumpjumper 27.5-inch bikes on home turf in Santa Cruz, Calif.
Mtbr got a chance to put a few hours on the new 27.5-inch bikes Specialized somewhat quietly introduced just before Sea Otter—the $6,500 Stumpjumper FSR Expert Carbon EVO 650B and the $3,400 alloy Stumpjumper FSR Comp EVO 650B. Both bikes fall into the trail/all-mountain segment with 150mm travel front and rear and represent two price points of essentially the same bike.
While Specialized initially resisted the new wheel size, they’ve now adopted the mid-sized standard, introducing tires in February and now bikes. With an accelerated timeline and some clever engineering, the company has brought some impressive, if not fully refined new models to market in short order. That said, it’s important to realize this first wave of 27.5-inch Stumpy FSRs are more-or-less retrofits, and not ground-up new designs.
While the spacers that make the Stumpjumper FSR 29er front end geometry work with 27.5-inch wheels are effective, they’re not quite elegant.
Stumpy geo needs a little bump to get rolling
Starting with the existing front end of a 29er Stumpjumper, Specialized added a 10mm aluminum spacer at the bottom of the head tube to correct the geometry for use with the smaller wheel size. They then added a newly-designed 27.5-inch-specific rear end that shortens the chainstay and other proportions. The resulting bike ends up with numbers in the ballpark of their existing 26- and 29-inch offerings. Though the effective seat tube angle sits at 74-degrees, the actual angle ends up between 68.4- and 69.7-degrees.
Rollin wet on the Specialized 27.5s
Evaluating a bike in a short session is never comprehensive, and the task was made more difficult by the drastic change in conditions we experienced just before our rides on the Stumpy FSRs. The week leading up to our test saw significant rainfall on the previously parched trails above Santa Cruz, Calif. that served as our test track. Soft ground ruled the day, with some sections snotty and slick with mud. Other sections fared better with grippy, albeit slow conditions more prevalent.
On the up-and-up
Like their counterparts, the 27.5-inch Stumpjumper FSRs both had an efficient climbing feel. Without the mud we added to them, the Expert Carbon EVO version weighs 25.6-pounds, while the alloy Comp EVO checks in at 28.4-pounds. But more so than a number on the scale, the bikes exhibited the signature stability of the FSR suspension that resists energy-sapping movement and makes them “climb light.” On roots and rocks, the suspension gets compliant and adds to the climbing prowess.
Not surprisingly, getting the front wheel up some ledges and roots took more effort than the Stumpy 29er which exudes a more roll-up-anything attitude. Without riding them side-by-side, it’s really hard to divine a difference between the 27.5 and 26er—though we suspect it would be much more subtle than the gap to the 29er.