Specialized's New 2FO DH Flat & Clip Shoes

The last decade has seen a steady increase in footwear models for flat pedal riders. Few, if any, have reached the level of grip available from the Stealth rubber that graces the sole of FiveTen shoes. That’s not necessarily a bad thing, with riders holding different preferences when it comes to grip vs some slip, but it is something many of us benchmark against.

But many riders still prefer a shoe with loads of grip on tap and their options have been limited. I’m one of those riders and every shoe I’ve ridden has been compared to the grip of the Stealth Rubber compound. It's not uncommon to see a comment that reads along the lines of; ‘why is it so hard for someone else to make a rubber like FiveTen?,’ beneath a shoe review either. Some flat pedal shoes have come close but nothing has quite matched up, until now.

Specialized’s latest rubber compound, SlipNot 3.0, delivers an experience similar to Stealth Rubber. How exactly did Specialized achieve the elusive grip and why did it take so long?

Highlights

• SlipNot ST (3.0) rubber sole
• Cushioned EVA foam midsole with shank layer for impact absorption and stability
• Reinforced upper for protection and foothold
• Leather and textile upper with added protection
• Xpel™ hydrophobic mesh construction
• Body Geometry
• Sizing (EU): 36, 37, 38, 38.5, 39, 39.5. 40, 40.5, 41.5, 42, 42.5, 43, 43.5, 44, 44.5, 45, 45.5, 46, 46.5, 47, 48, 49
• Colours: Black/Grey and Grey (flat) / Black/Red and Grey (clip)
• Weight: 448g/shoe (Size 44.5 EU/11 US flat shoe tested)
• MSRP: 160 USD (flat) / 170 USD (clip)

SlipNot ST (3.0) and the Battle For Grip

As it turns out, it really isn’t easy to produce a grippy rubber sole for mountain bike footwear. I asked Specialized Footwear Project Manager, Stephen Quay, what makes it so difficult and whether that was their goal.

Stephen noted that most rubber chemists aim to produce really durable traction rubber, similar to what's found on outdoor hiking shoes, or a resilient, efficient rubber, as found in tires. After much research and different approaches to achieving grip in their earlier shoes, Specialized knew they wanted a rubber with very little rebound – essentially a dead rubber. This style of rubber isn't common and Stephen said finding experts able to achieve this was tricky. But he did confirm that maximum grip was Specialized's goal for their flat pedal shoes, from the day dot.

They approached this differently with their outgoing 2FO shoe, the 2.0. For that shoe, the team used high-tech mapping software to monitor what happened to the foot over a section of trail. The section offered a variety of situations and they had Dylan (Dunkerton) and Curtis (Robinson) of the Coastal Crew, test repeatedly and provide feedback. Specialized's thought for the 2.0 was to make the sole soft, and coat it with a soft, low tensile, high elongation rubber; something closer to an elastic band.

The 2.0 provided grip thanks to the easily deforming base which allowed the pins of the pedal to penetrate effortlessly. However, this soft material produced a lacklustre hold on the pins once they were embedded into the shoe’s sole, allowing them to move while loading on the pedal. They also provided little support. Despite their lack of all-out grip, I found them to be an improvement over the original 2FO, which had a firm sole and rubber.

To achieve the most grip possible, Specialized began working on a midsole that was firmer, to provide an improved response but also force the rubber and the pedal pins to engage. With the help of some external rubber chemists, the rubber was changed to a durometer similar to the original 2FO flat but slower to rebound. Tensile strength is higher and the elongation percentage lower than 2.0.

That’s a fair bit of science, and there’s a podcast with Stephen that we’ll release very soon for those interested to learn more. In short, the higher tensile strength of the rubber holds the pin firmly in place while the right amount of elongation, or stretch, allows the pin to engage well. Add the slow rebound and once in place, the pin has less chance of bouncing out.

The important point is that it works. I’ve only had the chance to get a few rides in the new 2FO DH flat shoe but they immediately provided a strong hold and I haven’t had any situations where a foot has shaken loose. They’ve held strong through rough sections of trail riddled with square edges as well as high-speed situations where airing into more chop and rocks has done nothing to unsettle them.

At this time of year in Squamish, conditions are generally cold and my rides have been in temperatures ranging from 6–10 degrees Celsius. It’s been damp but not wet during the first rides with the 2FO DH but there have been no problems to note when it comes to grip.

Compared to FiveTen's Impact Pro, the grip has been at least equal and while it’s early days, I’d say the rubber latches on more instantly, which is good for keeping the foot in place when slightly unweighting but can make repositioning tricky.

The Midsole Matters Too

Anyone who rode in the previous 2FO shoe knows how soft the sole was. The foam resembled the goo of a marshmallow and while at the time Specialized felt allowing the pin easy penetration was good, they since realized it went too far. Now they’ve come back to what they hope is a happy medium.

Increasing the hardness of the foam midsole meant that Specialized had to nail the rubber outsole, which they appear to have done. The firmer foam makes the shoe more responsive to rider input than the previous shoe, which some of their team riders noted folded too much when riding aggressively. More support from the foam used in the sole provides a better response in these situations.

The 2FO DH Flat features a shank that runs roughly three-quarters of the shoe’s length, allowing the shoe to flex at the toe and heel to increase comfort off the bike. But the shank, and its placement, provide extra support in the sole for high impacts and high-intensity riding. The Roost, which looks very similar to the 2FO DH and features the same SlipNot 3.0 rubber sole, doesn’t feature a shank.

In addition to the shank in the 2FO DH Flat, Specialized has included the key components of their Body Geometry philosophy; the forefoot varus wedge, longitudinal arch support and a metatarsal button. As a rider with a high arch, I’ve noticed the benefits of elements of the system, particularly in their clip shoes.

With Specialized keen to strike a more casual appearance with the shoe, much of this tech is concealed. The footbed is their red, low-arch option (blue is average arch support and the green is high). These can be purchased separately for riders interested in a bit of fine-tuning.

Specialized worked with Xpel to create the footbed. Its appearance is interesting, with diamond shape cutouts throughout the bottom and perforations on the top to improve drainage. Limiting water absorption keeps the shoes lighter while riding — they already weigh ~200g less than the Impact Pro, per shoe —and they should dry more quickly post-ride. I haven’t been able to test this yet but from experiences with previous models, they should dry relatively quickly.

Thanks to my high arch, the footbed in the 2FO DH Flat provided a loose feel and left me a bit disconnected. This may be a good thing for riders not interested in the claimed benefits of Body Geometry, with the shoe feeling similar to a regular Vans skate shoe. I still found grip to be excellent and overall enjoyed riding them but once I put my usual footbed in, things improved greatly. The shoe went from feeling loose with a less than ideal fit, to really good, improving response on the bike. The toe box of the shoe feels roomier than the Impact Pro or Freerider Pro shoes that I’ve been spending most of my time in, but the outer proportions are smaller.

The sole thickness and overall stiffness strike a good balance, however, after only a few rides I’m unsure how they’re going to feel once properly broken in. I’ve done a couple of mild walks around the neighbourhood and worn them around the house before riding, but I typically break in my shoes more. Despite this, these have felt good on the bike, albeit a bit stiff through the middle for my liking. Perhaps once they're properly broken in this will mellow out but if not, the Roost may be the better option for me. The sole feels thinner than the Impact Pro and is more similar to the Freerider Pro.

Upper Materials

Specialized isn’t shy about its approach to the new 2FO DH shoe's casual aesthetic. One look at the shoe and it’s easy to see the similarities to the Roost, which is closer again in appearance to casual skate shoes. But there’s still plenty going on to help riders in a technical sense and it continues to the materials used in the uppers.

The appearance of the 2FO DH is where the similarities to the Roost end. The materials used carefully straddle street comfort and technical riding with some dating back to the first 2FOs. The sides of the shoe back to the heel are almost identical to Gen. 1 and are lightweight but relatively stiff. The Xpel hydrophobic mesh is found through the mid-section of the inside, allowing plenty of airflow but not much warmth in sub-10-degree C weather.

The poured PU forefoot of the original 2FO is gone, as is the technical captured foam (mesh, foam, TPU all welded together) of Gen. 2, replaced with a more comfortable material. It still features a tough toe similar to Gen. 1 for protection but the vamp (top front of the shoe/'toe box’) features a synthetic material. This material is said to crease better, providing additional comfort when walking. Until comparing this with the original 2FO I wouldn’t have noticed it but it does feel good.

As with the Roost that Cam reviewed recently, the lace loops are slits to keep the flat lace from twisting. On the 2FO DH, the loops feature nylon-like material on the outside, reinforcing the loop. The upper half of the shoe is relatively easy to tighten but similar to Cam’s experience with the Roost, the shoe requires you to individually tug on each section to tighten evenly throughout.

The 2FO DH Clip Returns

Specialized has released a new 2FO DH Clip that shares many of the features of the Flat shoe. The appearance is almost identical but there are some different materials in use through the uppers while the greatest differences lay in the sole.

The sole uses Specialized's Lollipop shank; a three-quarter length injection nylon that provides mount locations for the T-nuts, while the rubber compound is SlipNot 2.0.

The rubber sole prioritizes off-bike traction, abrasion durability and traction vs grip, like previous clip shoe models. Being mechanically connected to the pedal, grip from the rubber sole is less important and it needs to be durable enough to take the abuse of the pins, if any, being forced across the surface when untwisting to disconnect. Deniz has a pair that he’s testing so look for a review on them in the future.

Impressing A Shoe Grip Snob

I couldn’t help but notice during my conversation with Footwear Project Manager, Stephen Quay, that they've done a sort of bracketing while striving for max grip. They surely would've preferred to nail that right away, which he confirmed was their goal all along, but before doing so they went from one extreme to the other. The first version had several interesting features but ultimately the rubber outsole was too firm to provide heaps of grip. The clip version of that first shoe was one of my favourites at the time. Then their journey took them to the other end, with one of the softest soles, and rubber I’ve ever experienced. It was comfortable to wear around town but struggled to provide adequate pin hold for the max grip crowd.

Now seven years after their first attempt, Specialized has pretty much nailed it, firmly planting their (sticky) foot in the ring. While it’s still early days, this shoe grip snob is having a fantastic experience with these shoes. SlipNot 3.0 produces a grip similar to my beloved FiveTens in a lighter package that promises to hold less water and increase breathability. The technical features of Specialized shoes carry over in a less boisterous manner, with a less technical appearance.

I’ll continue riding these as the weather warms, since they’re a tad cold in the winter conditions, and report back on anything notable, including comments on durability. Early impressions are positive, especially for riders interested in all the grip.

More on the Specialized 2FO DH shoes.