So this is a pretty interesting development. Several companies have begun partnering with BOA to apply the company’s signature “crank and cable” lacing system to their shoes. New Balance already used it on the Vazee Sigma sprinting spike, and now it makes its way to their regular trainers.

The Sonic’s midsole is pretty much the same as the Fuelcore Rush v3. It has great responsiveness and strikes a balance between firmness and cushion. The outsole is the big difference, here. It has a more “wave”-like pattern (versus the Rush’s angular design) and the medial outsole doesn’t run the entire length of the arch, just most of the way. As a result, there’s less of a “rocking” feeling when in motion, but the stability isn’t really compromised. That latter point is also because of the upper, so let’s talk about that.

Let’s be honest, this is the meat and potatoes of the Sonic. The whole upper feels almost like a second skin. The strap wraps the midfoot and can be tightened to comfort. So you can make it pretty tight to completely lock yourself into place and grant more stability. My flat feet were completely comfortable and since I love tight shoes, I could really personalize the fit. One concern I had before trying on the shoe was that since the strap only covered the part of the foot closest to the shin, there wouldn’t be enough control over my toes. The “NB” logo overlay actually comes into play here and serves a functional purpose. It stiffens the area above the toes, so it doesn’t feel too sloppy. You have a secure, yet free feeling. One note: I spoke with another gentleman who wore the shoe and he said that the BOA dial dug into his foot when he flexed it. This was not an issue I experienced and my theory is that his arches were a bit higher than my own.

The New Balance Fuelcore Sonic is certainly a unique shoe. It’s designed for speed and its elements will probably have a pretty big appeal to triathletes. It’s a great all-around shoe that lets you customize your fit and feel like there’s practically nothing on your foot at all.

Score: 9/10

Comparable models: Asics Noosa FF, Skechers GoMeb Razor

New Balance Women’s FuelCore Sonic
New Balance Men’s FuelCore Sonic