Having run consistently for more than twenty years, I feel that I not only have a pretty solid idea of what I want in a shoe, but that my needs now are also somewhat specific due to the cumulative effect of inevitable wear and tear on my joints. The quest for “my” perfect neutral running shoe has been ongoing for a number of years, and I’m happy to say that the Karhu Flow Tri Fulcrum seems to fit the bill, and is easily one of the best shoes I’ve ever tried.
I’m lucky enough to live in Southern California and have year-round access to a great variety of road- and trail-running. So far, I’ve put about 80-100mi on these shoes, on all kinds of surfaces ranging from flat concrete to packed dirt to rocky trails. Even though the shoes are very light and the profile is low (heel-toe offset is 8mm), these babies are sturdy and supportive enough to tackle almost any terrain with ease. The sole also provides excellent traction, which is particularly reassuring on loose gravel and hills, and something I’d been missing in comparable but flimsier designs from other brands. The heel collar, which gently “cups” the back of the ankle into the shoe, is another excellent and totally unique design feature, and contributes significantly to an overall sensation of snugness and support without adding bulk to the shoe.
Karhu has also clearly paid a lot of attention to detail when it comes to the functionality of the Tri Flow Fulcrum. I absolutely need my shoes to be laced to the exact same degree of tightness on both sides for distraction-free running (hopefully I’m not the only weirdo that thinks this?), and feeling lopsided while racing is a deal-breaker. So, I have much appreciation for the quick-pull stretch-cord clasp fastening on these shoes. Even better: the wide velcro strap across the top of the shoe locks the whole thing in place, supports the medial arch of the foot, makes adjustments a piece of cake, and looks super snazzy. Given the time-saving nature of these neat add-ons, I imagine that triathletes are especially stoked on these features as well.
Moving on to the piece de resistance of the Tri Flow Fulcrum: the EVA fulcrum heel insert, a triangular wedge-shaped insert in the rear foot. This heavily-researched piece of technology claims to increase the efficiency of your gait cycle by eliminating unnecessary vertical bounce and propelling you forward instead. For me, this design definitely goes a long way towards encouraging a mid-foot strike, as well promoting a natural forward momentum. The fulcrum also curbs my propensity for overstriding, which in turn keeps my knees from getting cranky after longer runs. All in all, the cushioning of the sole is wonderfully balanced: the shoes themselves completely mold to and support the natural shape of my foot, thus becoming a non-factor in the best possible way. Similarly, while I’ve been annoyed at overly loose, splayed-out toe-boxes in comparable shoes, the forefoot here is pleasantly compact without being in any way restrictive.
Even though this is a specialized running shoe, I’m extremely impressed with its versatility. I’ve found other neutral sneakers to be awkward to walk in, but I can happily wear these Karhus all day (and often do, since I work in fitness). They’re far from a one-trick pony and carry over to other activities remarkably well: I use them for Crossfit and find them supportive enough even for the huge variety of movements required there. If I had to dig for one thing that could be improved on, it would be tongue, which does tend to slide off to the outside of my foot during longer runs. On the whole, though, I would wholeheartedly recommend these shoes to anyone looking for a significant upgrade from their current kicks.