Salomon's town-to-trail hybrid line has always sold itself on not making the runner choose, and the fourth-generation Aero Blaze GRVL sticks firmly to that brief. It is a road shoe with a gravel-rated outsole rather than a trail shoe wearing a road shoe's clothes, and the changes for version four are narrow and specific: a new lacing system, a slightly taller stack, and an upper reworked for visibility, with the foam and outsole compound left alone because, evidently, nobody at Salomon felt they needed fixing.
The headline change is the Quicklace Neo one-pull system, the line's first departure from conventional eyelets. It tightens the shoe evenly across the midfoot with a single motion rather than a lace-by-lace ratchet, and it is the sort of update that matters more in transition zones and gravel-adjacent group runs than on a Sunday long run, where most runners will barely notice they are using it. Salomon has also redone the engineered mesh upper with added reflective detailing, a sensible nod to the shoe's most obvious use case: runners heading out before or after work, in low light, on routes that mix pavement with towpaths, canal paths and unlit gravel.
Underfoot, the heel stack rises from 35mm to 37mm, still built on the same optiFOAM2 compound Salomon has used across the line. Our early impressions in testing echo the wider consensus: slightly greater heel cushioning and a touch more energy return than the version three, without any change in how the foam feels at the point of toe-off. That consistency is deliberate. Salomon's optiFOAM2 has become the known quantity in this shoe's identity, and the brand appears more interested in refining the chassis around it than in chasing a newer, splashier midsole.
The Gravel Contagrip outsole carries over unchanged, with the same 2.5mm chevron lugs that made the version three a credible crossover shoe rather than a road trainer with delusions of trail capability. That continuity means the durability profile is a known quantity too: enough bite for canal paths, fire roads and wet cobbles, not enough for anything technical or steep. At $140, with a Gore-Tex variant available for wetter climates at the usual premium, the Aero Blaze 4 GRVL remains positioned as the lighter, more breathable half of Salomon's town-to-trail pairing, built for runners who want one shoe that will not flinch at a change of surface halfway through a run.
None of this amounts to a reinvention, and Salomon does not appear to think one was needed. The Aero Blaze 4 GRVL is a shoe that already knew what it was for, made marginally better at doing it: easier to get on, slightly more cushioned, and just as happy on a towpath as on tarmac. For runners who split their week between road and gravel and have no interest in owning two pairs of shoes to do it, that is close to the entire pitch.