Review: Speedland GS:TAM Trail Shoe

The latest Speedland shoe was created in partnership with elite ultrarunner Dylan Bowman and is named after Mt. Tamalpais in Marin County, CA, where Bowman first rose to fame and built the foundation of his professional career. Marin County is also where Bowman tested a prototype of this shoe on his way to a first-place finish at the 2022 Miwok 100K. We tested it through miles of steep, sloppy running, including a few 20-mile outings, and will almost certainly employ the shoes in 100k and 100-mile events later in the year.

As with the two previous Speedland models, the GS:TAM will be made in a limited production run. This model features cutting edge technology along with customization options to accommodate a variety of runners. However, unlike the previous Speedland shoes, this model takes a pleasant departure in the cost category, coming in a full $100 less than the high price of the company's first offerings. Somewhat ironically, for the lower price tag you get a lot more shoe. It's a max-cushioned model that sits 9mm higher in the heel than previous Speedland shoes (with a heel-toe drop that is 2mm steeper) and maintains the same approach to premium materials and construction that the company was founded upon.

Thick heel stack height

Uppers on the GS:TAM consist of a mesh material that has good breathability and is reinforced with high-tenacity fibers in strategic flex points, along with a thin TPU film at the toe cap to increase durability. The upper includes an integrated knit bootie and is secured by four straps of synthetic suede in a PerformFit Wrap system anchored by dual BOA Li2 dials. These dials aren't made of anodized aluminum like the previous Speedland SL:HSV shoe, but are similar to the hard plastic found on the original SL:PDX model. In testing, the aluminum dials were definitely easier to grip and manipulate in wet, cold or sloppy conditions, but we were still able to manage this without too much trouble in the GS:TAM.

Dual BOA Li2 dials

The clear strengths of the Li2 dual dial system are the "zonal control" it offers for customizing the fit from ankle to forefoot, and its bi-directional functionality for micro adjustments in either direction. Being able to ratchet the system down a couple clicks before a steep downhill or to loosen them by a couple clicks if your feet start swelling late in a run, is a huge factor in long-term comfort of the shoe. Laces of the BOA system are reinforced with Dyneema for high resiliency, and we haven't experienced any wear concerns with similar laces on other Speedland models. However, we do see a couple of recurring quirks with this lacing and upper combination on all Speedland shoes, including the GS:TAM. One issue is that the laces tend to slightly loosen during long runs, so we occasionally find ourselves ratcheting them back down a notch or two during multi-hour efforts. The other thing we found is that when ratcheted down tight, the ankle collar fabric bunches slightly below the laces and causes some mild gapping around the ankle collar.

Slight bunching of fabric from laces, and gapping of ankle collar

The midsole is the real attention-grabber of the GS:TAM for its prominent thickness, wide base and use of high-end Pebax material throughout. The midsole is actually two separate components: an "external midsole" of beaded Pebax that has high compression resistance and energy return, and a removable internal "drop-in" midsole of blended Pebax that enhances cushioning. Having said that, Pebax is definitely firmer than traditional EVA compounds, so the overall ride quality of the GS:TAM is noticeably firmer than something with a similar stack height from HOKA or Altra, for example. This probably favors faster, performance-based runners that are Speedland's target demographic, but our back-of-the-midpack tester found them comfortable for several hours on the trail. Pebax has a reputation for excellent longevity among midsole compounds, and Speedland claims that this particular model has been tested over 600 miles with minimal signs of compression or decreased performance which is a cool way of saying that the outsole will probably wear down before the midsole does.

Medial view

One noticeable difference between the GS:TAM and previous Speedland models is the added stability element in the midsole construction. The perimeter of the drop-in component is slightly wrapped by the external component and built with mild concavity to cradle the foot. Additionally, the midsole compound exceeds the lateral borders of the last through the length of the shoe, creating a larger base of support. At first glance, it looks like the last itself is wider than previous models, but the interior dimensions feel about the same. We found the Speedland last is somewhat wider than average, with plenty of room in the rounded forefoot for toe splay or foot swelling, but narrow-footed runners might find them too roomy.

Forefoot of HSV on L, TAM on R

Another remarkable aspect of the Pebax midsole is that its enhanced thickness doesn't come at the expense of increased weight. The GS:TAM has the same spec weight as the lower profile SL:HSV model, making the cushioning-to-weight ratio of the GS:TAM among the best in the industry right now. One caveat of the GS:TAM spec weight is that it doesn't include a Carbitex plate like other Speedland models have, however, the shoe will accommodate the inclusion of this plate for those who want to purchase it separately. We are big fans of the Carbitex technology for improving performance, as it can function as a thin rock plate while also enhancing forward propulsion, but for runners mainly looking for comfort, stack heights on the GS:TAM are sufficiently high enough that your ride quality isn't compromised by the absence of a plate.

Michelin OC1 rubber outsole

Outsoles of the GS:TAM consist of a Michelin OC1 Fiber Lite rubber compound that is similar to the one used on the original SL:PDX model. The compound is applied less generously than on the debut model that featured full underfoot coverage, which helps shave a bit of weight, but overall coverage is pretty extensive in all the key high-impact areas including the medial portion of the heel, which many companies underemphasize, but pronators will tell you is always the first section to wear out. This outsole is one area where Speedland somewhat dialed back the customization options, as the standard configuration uses 4.5mm lugs instead of the previous 7mm lugs that could be clipped down on previous models. There is a single drainage port that can be punctured to enhance water removal, but it's oddly positioned compared to other models, located almost directly under center midfoot as opposed to the instep area. It's so small that it doesn't seem to make a dramatic difference in drying rate.

From a performance standpoint, the OC1 compound has been excellent in our previous SL:PDX testing as well as with the GS:TAM. It rolls smoothly on mild surfaces and grips very well on hard gravel as well as stream crossings and mud. The only conditions where we found ourselves being somewhat cautious were highly technical roots or scree, but this had as much to do with the high platform as it did with the underfoot traction. From our testing with the SL:PDX shoe, durability of this outsole compound is dependable for at least a few hundred miles or longer if you are an efficient runner with no abnormal wear patterns.

Dual BOA Li2 dials

When the debut Speedland model launched in 2021, we noted that the brand's "no compromises" approach to design and construction was very compelling and the company would definitely be worth keeping an eye on if they eventually offered a more affordable option. The GS:TAM represents a significant move in that direction, offering top-of-the-line comfort and performance. With numerous trail shoes in excess of $200 on the market, the price point isn't nearly as much of an outlier. We could see this shoe becoming the Speedland model that attracts a mass customer base (depending on the production run, of course) among the ultrarunning community, and it's one that we plan to use extensively in 2023.

The Speedland GS:TAM shoe is available in unisex sizing from www.runspeedland.com.

Features and Specs:

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Donald is a physical therapist, California native, barefoot aficionado, and father of three with more than 25 years of experience in endurance sports. He was a collegiate rower at UCLA, then dabbled in marathons and Ironman-distance triathlons before falling in love with ultras in the early 2000s. His favorite locations to run include Marin County, CA, and the Sierra Nevada mountains, and he loves exploring America's National Parks. When he's not training for ultramarathons, he enjoys hiking or slacklining with his family in Monterey County, CA.