Review of the Salomon Sonic RA Pro and S/Lab Ultra Running Shoes

I've branched out quite a bit in my shoe usage over the past couple of years. I've been pretty loyal to inov-8 since discovering their shoes in 2008, and I still have several of them in my quiver. The X-Talon 212 may be my second-favorite shoe of all time, after the old c. 1991 Nike Air Terra Zori. (Does anyone remember those? They were purple with yellow trim, lightweight, flexible, grippy...I had so many fun miles in those shoes. I can't even find a picture of them on line.) But in recent years I've expanded my arsenal to include some HOKAs (enjoying the Speedgoats), a couple of Nikes (the Wildhorse for trails and the Zoom Fly for speed work), and some other random stuff from Scott and Newton. By far my biggest change came in 2018 when the MPF/RNR team partnered with Salomon and I was able to try out some of their high performance shoes.

Previously I had not enjoyed some of my forays into the Salomon line. I liked the Sense Mantra OK, and had a brief flirtation with the Sense Ride (I think), but found many of their other offerings, like the XA Pro and the Wings Pro, to be very stiff and unresponsive. Plus I find their naming system to be incredibly confusing. So I was a bit apprehensive when this partnership was announced. Fortunately mears fears were unfounded. I've fallen in love with two different models this year and wound up turning in the majority of my 2018 miles in Salomons.

First up: the Sonic RA Pro. This is billed as a road shoe, and it definitely fits that bill. I come from a road background, though, and I still do a fair bit of road running: probably once a week tempo or marathon-paced running on roads, plus a few miles at the beginning and end of some runs getting to the trailhead from my house. Additionally, most of my "trail" runs are actually carriage roads, where footing is generally excellent. I have some very light, very grippy, very responsive shoes that I'll wear if I know I'm heading for a technically demanding route. In general, when I'm looking for a workhorse training shoe, I want something that can handle a bit of road and a lot mostly non-technical trails, which means I'm willing to sacrifice traction and, to a certain extent, weight, in exchange for cushioning and versatility. The one thing I can't abide is stiffness. Even in a road shoe, I need a responsive ride. The Sonic RA Pro checks all of those boxes. 

My Sonic RA Pros after their muddy maiden voyage

My Sonic RA Pros after their muddy maiden voyage

At 235g (8.3 ounces), they're light and responsive, but there's enough cushion for a longish run; I took them for multiple 20+ mile runs without feeling beaten up afterwards. The 6mm heel-toe drop is about the limit of how low I can go without really bothering my Achilles. They transitioned from road to trail with ease, and I was able to use them on some of the exposed rock slabs in the Gunks without feeling unstable. The toe box was extremely accommodating of my wide forefoot, but the Sensifit system provided a snug fit that hugged the midfoot extremely well, and I did not appreciate any slipping or sliding in the forefoot as a result, despite, the extra roominess. The upper was light and breathable. Not an awesome shoe for mud--the blown rubber outsole slides around too much, and the upper doesn't do much to keep mud or moisture out. But the shoe scored high marks for responsiveness and versatility, and I wore them for the Salomon OutdoorFest 6-hour in June with no complaints.

As I geared up for Leadville, however, I knew I'd need a shoe with a little more heel-toe differential to protect my Achilles over 100 miles, and I definitely wanted a little more cushioning than the Sonic RA Pro could provide. I considered using the inov-8 Roclite 280s, which I'd used at Bandera in 2016, or the Race Ultra 290s, which I'd used at Rocky Raccoon in 2017. But the Race Ultras had been feeling a bit clunky recently, and so after OutdoorFest I started putting in miles in the S/Lab Ultra. I think it took two runs for me to be certain that these were my shoes for Leadville.

The S/Lab Ultra is also known as "the Francois shoe" as it was developed with multiple-time UTMB champ Francois D'haene. I'm not sure if I can adequately describe how much I love this shoe. It weighs 300g (10.5 ounces) but feels lighter. It rides low to the ground (26mm stack height in the heel) but yet feels cushioned. It's grippy but not overly aggressive; flexible but not too soft. The 8mm drop is right in my sweet spot. Like the Sonic RA Pro, it has Salomon's Sensifit technology for a wonderfully comfortable grip in the upper, which has a bit more overlay than the former shoe but stops short of being too hot or restrictive. I'd probably prefer regular laces to the Quicklace system, which I find can be difficult to tighten enough for really slippery conditions, but it does prevent the dreaded "lace bite," and I did appreciate the easy on/off when I changed my socks at mile 61 of Leadville. I'd love to find something negative to say about these shoes, but I can't. I even like the color. They're coming with me to Rocky Raccoon next month, and I know my feet will be in good hands.

But I still hate the naming system.

My trusty S/Lab Ultras in action at Leadville | photo: Joe Azze

My trusty S/Lab Ultras in action at Leadville | photo: Joe Azze