The Start of SL20
There is one pair of running shoes within the Adidas’s line up which does not get much recognition and excitement over. No coverage, no mentions, and just listing on its product page. The pair is the SL20. Launched about 3 years ago and the first with the introduction of the full length Lightstrike midsole foam from Adidas only. The SL20 brought fans and non-fans into the brand’s product line up from the hype it has created. The SL20 is a budget friendly performance running shoes from Adidas.

A Radical Change with SL20.2
Deep discounting followed shortly after the SL20 started to get out into the market. Some observers wondered if the SL20 was a one-shot product by Adidas to test the market with as Adidas continues to flood the market with new colourways and deep discounting. As the year went on, without much announcement, the SL20.2 (not the SL21) came into the market.

It was a departure from the SL20 version 1, the upper had a facelifted, and the outsole revamped. The first key change was the midsole with its higher stack height in the forefoot to provide additional cushioning. With the additional cushioning, it allows runner to expands the use cases for the SL20 series as compared to its predecessor. Another key change is the removal of the torsion system and the outsole. The torsion system is one of Adidas’s features shoes such as the Adios Adios series or the older Adios Boston series (excluding Boston 10). The torsion system is a thermoplastic which provides an element of stability and prevents excessive lateral twisting. In SL20.2, a wider base and extended rubber coverage in the outsole replaced the torsion system.



The durable Continental remains a feature in the SL20.2. The outsole design changed in this and the subsequent version to the lateral side of the heel and medial side of the forefoot. A welcomed move to lengthen the durability of the running shoes.
The Release of SL20.3?
No one knows for sure what this change in the SL20’s design meant. Is it here to stay or is this yet another testing thrown to the market by Adidas? Fast forward and we know the new design is here to stay when Adidas released their SL20.3 in 2022. At first look, one might wonder what has changed to the SL20.3 over its previous generation. It looks very similar.


At closer look, the SL20.3 has notable differences. The first is the change from underlay to overlay in its upper. The upper also has a more breathable upper compared to before, with more ventilation holes extending towards the ankle. This will improve the breathability for the SL20.3, a primary concern for those living in warmer climate. The heel area also no longer spot a plastic support (the grey area). In the SL20.3, we can see that there is a single strip running from the heel area all the way towards the toe cap area. The height of the heel collar has increased in the SL20.3 coupled with thicker laces and an enlarged Adidas logo.
While looking similar, Adidas has made considerable improvements to the SL20.3. These changes improves the appeal of SL20.3 to compete with the likes of Nike’s Winflo series and also the New Balance’s upcoming Tempo v2. Noting the updates to the SL20.3, it makes me wonder if in the next update for the SL20, will we see improvement to the midsole and outsole, similar to Nike’s practice of introducing changes.
Conclusion
Previously, with the similarities between the SL20 and Boston series, it was a confusing and conflicting choice for runners. Yet the SL20 series is slowly finding its spot in the line-up after the release of the Boston 10 as well as the Adios 6. Adidas has made considerable improvements to the SL20.3 enhancing its competitiveness in the market. I am hopeful that the SL20 series is here to stay with the release of the third version.