By Tom Demerly.
Once you go under 10 ounces in a running shoe you have to give something up. For most shoes, it is stability. For some shoes, you lose cushion. Asics GEL-DS Sky Speed 2 manages to retain enough of both to make this a viable everyday shoe from a category usually reserved for race day and speed work. For runners this is interesting. For long distance triathletes it’s a secret weapon.
Triathletes run on tired legs. Not all of us are 130 pounds. Ultra-lightweight racing shoes designed for runners often fall short on motion control and cushioning we need to provide a soft, stable ride on tired legs. A few triathlon specific running shoes such as K-Swiss and Zoot have evolved to meet the rank n’ file triathletes’ needs.
until now the big running brands have missed the mark with a light weight shoe that runs well off the bike with enough cushioning and motion control for tired legs.
Asics has it right with their GEL-DS Sky Speed 2. The GEL-DS Sky Speed 2 provides enough cushion and stability to do Ironman distance races and retains light enough weight to provide an advantage over a 12 ounce shoe like the GEL-Cumulus 13 cushioned trainer.
The GEL-DS Sky Speed sits in Asics “Speed Collection- Training” that includes four shoes between 10 and 8.9 ounces advertised weight. The four shoes are tuned with uppers, midsoles and ride control features to produce an amazing variety of ride characteristics. The GEL-DS Sky Speed 2 is the “down the middle” shoe with a long list of Asics buzz words to describe the technology that reduces weight and controls ride. At the opposite end of the spectrum is the GEL-Speedstar 5, a less structured upper and foam padded moccasin of a shoe that could work for everyday running, but not for me at 170 pounds and a list of knee surgeries and other orthopedic dings and dents. Sitting below the Speed Collection- Training is the Speed Collection- Racing. The Racing shoe line features the GEL-DS Racer 8 at only 7.6 ounces advertised weight. This isn’t an everyday shoe. The GEL-DS Sky Speed 2 is an everyday shoe, and there is the niche for Asics- a light shoe that can go the distance on tired legs.
The GEL-DS Sky Speed 2 uses a few other bells and whistles that create beautiful music for the triathlon runner. Asics uses the stretch fabric Biomorphic Fit Upper in the GEL-DS Sky Speed 2. This design feature allows a wrinkle free interior without socks by using stretch fabric to improve fit precision. There is a noticeable amount of give in the upper. This shoe is very quick to don with speed laces and once on your foot finds its “sweet spot” instantly. Asics also uses their version of anatomical lacing. The Asics version follows a different path across your upper than other anatomical lacing but facilitates great fit. Drainage on the shoe is so-so and this is one area where, if Asics decided to do a triathlon specific version, they could make changes.
The central feature to ride quality on the GEL-DS Sky Speed 2 is the Asics Design Philosophy “I.G.S.” or Impact Guidance System. I.G.S. is the synergistic outcome of all the Asics ride control buzzwords. I’m buzzword-saturated when I review running shoes. I will suggest the missing ingredient is an adequate enough medial forefoot. As a runner in a long triathlon becomes fatigued they tend to lapse into the “Ironman shuffle” somewhere north of 9 or 10 minute mile pace. While the difference between one shoe or another won’t give you a 30 second advantage, it will make you more comfortable and less sore with lighter weight to lift on every stride. That’s an advantage in the last four hours of a long race.
Another interesting feature on the GEL-DS Sky Speed 2 is the Asics Propulsion Trusstic, a plastic exoskeleton that acts like anti-sway bars on a car chassis. The Propulsion Trusstic resists twisting of the shoe at the narrowest point, the midsole, but allows the forefoot to hinge or “decouple” easily. Bending the shoe to run takes little energy- a good thing. Twisting the shoe to exert extra leverage on connective tissues is much more difficult- also a good thing. The net result of these features is a better ride than other 10 ounce shoes.
A few nice details in the upper round out the weight saving features and make this shoe race- day friendly, especially with speed laces. The “Discrete Eyelets” are simply holes in the polymer fabric upper section that hold regular and speed laces well but add no weight. These work particularly well with speed laces like Easy Laces since you can adjust the “snug-ness” of the forefoot and not lose that adjustment since the sides of the lacing holes seem to grip the speed lace better than a plastic-glide type.
The Asics GEL-DS Sky Speed 2 seems to ride a little low-ish compared to a full-blown trainer. My measurements did not support this feeling though. I put this shoe at 28 millimeters high in the heel and 17 millimeters high in the toe for a drop of about 11-12 millimeters depending on where you measure. This is not a low drop shoe. This drop does mimic, in proportion, the drop of the Zoot Ultra Ovwa- a 10 mm drop shoe. Zoot feels this is a good drop for running out of T2 on tired legs and Asics does well to share this geometry.
Running in the Asics GEL-DS Sky Speed 2 is reassuring for lightweight shoe- especially in forefoot stability. Most sub-10 ounce shoes cave in to the medial forefoot for me. Not this Asics. It has a steady, straight, level ride. The “decoupling” of the rear from the front via the Propulsion Trusstic actually works. That makes the shoe delightfully flexible.
The Achilles heel of most lightweight shoes is their heel. There is enough heel on the Asics GEL-DS Sky Speed 2 for me to use it as an everyday runner. This shoe will go the distance at under 10 ounces in smaller (sub size 10) sizes for the Ironman distance runner. It will breathe fire at shorter distances.
Asics is a running footwear technical specialist, so I expect nothing less than great running shoes across their entire range, and the GEL-DS Sky Speed 2 is no exception. Now what I’d like to see from the Asics development sensei is a GEL-DS Sky Speed 2 with integrated speed laces, large drainage holes, a more ventilated upper and a pull tab on the heel for the tri-specific crowd. In the interim, it is worth the effort to retrofit speed laces to this shoe and hope for the best for drainage.