If full tilt, red-lined trail running is your aim, you need to give the Superior 4 a serious look. For top-speed laps it pays to have the lightest possible shoe, and the new design and construction of the Superior brings you about as close to that mark as you can get. Weighing in at 234 g each (468 g or 16.5 oz for a pair in men’s size 8.5), these are some of the lightest trail shoes on the market. Much of the weight savings comes from the midsole, which is built from Altra’s Quantic foam, a lightweight material that still provides the cushioning and shock absorption required for trail running. On the outsole, the MaxTrac rubber lining and deep lugs ensure a sticky grip on rocks, mud, and loose surfaces. The uppers are also pared down to the bare essentials: thin, breathable fabric over the toe box with just enough padding around the heal to make them comfortable.
At first glance, the idea behind this shoe seems like a contradiction, especially coming from Altra. Their design credo has been the super-wide “FootShape” toe box, intended to promote a more natural splaying of the toes while running. Combining this loose-fitting toe box with the flexible Quantic foam in the midsole and bare-minimum upper should really result in an unstable shoe that would feel pretty squirrelly on the trail. But as soon as you lace up the Superiors, you can already tell that fit and stability are not going to be an issue. Surprisingly, they run as solid as shoes with way more midsole and upper support.
After a few miles and a lot of debate, I’ve concluded the Superiors solve the stability issue with two design features. The first is the wrap around upper, which makes the tongue of the shoe continuous with the upper on the inside of the foot; and the second is the fairly deep heel. When you tighten down the laces, the upper compresses around your foot with a sock-like fit, and really locks your heel into the back of the shoe. The net result is that the shoe is tight and secure under your midfoot and around your heel, so that the loose fit in the toe box doesn’t compromise stability. The wrap-over tongue seems to turn a lot of runners off, but I bet once you put these to the test on the trail you’ll wonder why more shoes don’t copy this design.
For trail shoes with minimal midsole like the Superior, it pays to use good footwork to avoid big impacts over sharp edges and stones. If you haven’t tried a shoe like this before, be prepared to start paying more attention to the lay of the trail immediately in front of you than you might have before. Compared to a shoe with an integrated rock plate and more substantial foam, the Superior will require more quick adjustments to your stride over complex terrain. If you’re experiencing discomfort on sharp landings, Altra includes a removable TPU rock plate with the shoe that slips between the midsole and your insole to help dampen the impact. After trying the shoe with and without the rock plate, I found that the insert isn’t really as effective as you’d hope. Ultimately, I ditched the rock plate in favor of keeping the shoe light and fast.
The Superior 4 also packs a few other minor design elements that are worth noting. At the back of the shoe, one of the features I really enjoy is the slightly rounded outsole just behind the heel. When you kick it into high gear and stride out on the flats, this softened edge ensures your foot strikes roll naturally and in control. At the front of the shoe, there are four smartly placed holes that allow water to rapidly drain out the toe box. After a few wet creek crossings, I was genuinely impressed by how quickly the shoe drains water, and you can see that the holes in the toe box are doing their job. As with Altra’s other trail shoes, the Superior 4 carries the hook-and-loop “Gaiter Trap” behind the heel and clip in point in front of the laces, so they are trail gaiter compatible. (If you skip the gaiter like me, it takes all of five minutes to trim these doodads from the shoes.)
Although my Superiors have held up remarkably well so far, there are a few durability warning signs to be aware of. These aren’t much of a surprise, given that shoes in this category really aren’t intended for high durability. First is that there is a fair amount of the Quantic foam exposed on the outsole, and it’s already chipping away, even though the MaxTrac rubber is still looking fairly new. My guess is that the foam will give out before I actually make a real dent in the rubber. Second is the lightweight fabric around the toes. While the uppers are nicely reinforced around the heel and laces, there are bits of exposed fabric along the inside and outside of the toe box that I’m sure are going to hole out first (this is a common failure point on all my shoes, and probably differs for you depending on your foot and stride).
Overall, I give the Superior 4 the stamp of approval. This is a super fun shoe for pushing your PRs on Eastside trails, and has worked really well on everything from Bishop Pass to Pine Creek, Rock Creek, and Silver Canyon. Incidentally, I also think the low stack height and breathable materials make them a decent gym shoe as well, so you can really get your money’s worth.