ASICS Japan has recently released a new pair of running shoes – the S4. The S4 stands for Speed, Stability, Safety, and Sub-4 (hours marathon). Equipped with ASICS FF Turbo for its upper layer of midsole, with Flytefoam for its bottom, and ASICSGRIP for its outsole, the S4 is another one of ASICS race-day option. ASICS target to make this pair of running shoes the race day option for those looking to do a sub-4 marathon.

ASICS Japan S4

Yet there remain some questions upon the product release. This is because ASICS also has another similar pair of running shoes – the Magic Speed 2. Both are ASICS’s carbon plated running shoes which share some similarities (e.g., dual midsole). In terms of comparison, here are the statistics for the two.

ItemS4Magic Speed 2
Midsole TechnologyFF Blast Turbo w/ FlytefoamFF Blast Plus w/ Flytefoam
Forefoot Stack Height28mm24 mm
Heel Stack Height34 mm31 mm
Weight240 grams240 grams
Price22,000 yen16,500 yen
Table 1: Comparison between S4 & Magic Speed 2

Why is there a S4? Isn’t there a Magic Speed 2?

Personally, prior to the S4, I have considered the Magic Speed 2 to be both a trainer for the Metaspeed series as well as a very capable racer. Now with the S4, ASICS is hoping to cater to runners looking for a top-notch run day running shoes that isn’t the Metaspeed series. From what I learnt, the S4 fits just between the Magic Speed 2 and Metaspeed series.   

The S4 certainly has features setting it above the Magic Speed 2. One is the midsole foam used in the S4 being FF Blast Turbo, similar to that used in the Metaspeed series. Another is the higher stack height yet maintaining the weight at the same level. Looking at the upper, the S4 is toned much more for the race day fit over the Magic Speed 2. Another important feature of the S4 is the widen base contributing to a more stable ride.

How does one choose between the S4 and the Magic Speed 2?  

With the release of S4, one important question comes into my mind. How does one choose between taking the S4 and the Magic Speed 2? Without trying out the running shoes it will be very difficult to determine and compare between two shoes. However, looking at the specifications and design of the S4, I am certain that the ride would be even more responsive than the Magic Speed 2. At the same time, a higher stack allows for additional cushioning and material to load the carbon plate. Perhaps, the difference between S4 and Magic Speed 2 makes it viable to consider the S4 as a race day option and training option. While the Magic Speed 2 remains tied as a trainer for those using the Metaspeed series as race day.

Nonetheless, it seems that ASICS is jetting ahead with products which might make it into the hands of runners. From the refresh of Gel-Nimbus 25, the release of Evoride Speed, the incorporation of “Trail”/TR series in road running, and now the launch of S4. This is a welcomed move as ASICS can shake up their product line-up to match changing demands with new and interesting product offerings.

At the moment, only ASICS Japan has the S4 available in Hazard Green/White. No mention of when the other markets will get it but do stay tune! Till next time, just keep running.

2 thoughts on “A Sub-4 Marathon Specific Shoes? ASICS Japan released the S4

    1. Hi Frankie, based on what I know this is a Japan only release this far. I am not sure if ASICS will be bringing it to other markets.

      Here is the S4 on ASICS Japan. If you are interested in the S4, you can consider the upcoming Magic Speed 3.

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