First impressions have held up for the S Lab Sonic- both positive and negative.
A final update for the S Lab Sonic is posted here.
I have put about 500 km (300 miles) on the S Lab Sonic and have found the shoe to deliver as a slightly improved replacement for the the 2015 S Lab X-Series. The improvements noted in a previous review have all been verified and distance tested. I would have more miles on these shoes but they are currently in a rotation with two other pairs of S Lab X-Series. On a positive note, the rotation does, however, give the opportunity to compare and contrast the S Lab Sonic with the X-Series regularly.
Fit and Feel
As noted earlier, initial runs in the S Lab Sonic indicated that the fit and trail feel were somehow improved from the already excellent performance of the 2015 X-Series. These improvements have held up and continue to be evident with use.
The trail feel is exceptional with a nice balance of flexibility, protection, and grip. Part of this improvement is due to material choice (the new upper mesh material) and design (more extensive TPU overlays throughout the upper), but there also seems to be additional mid-foot support that is not as noticeable in the S Lab X-Series, but leads to additional comfort on any run.
The toe box width has been slightly enlarged relative to the X-Series and this also increases comfort just a bit- particularly on long (>30 km/20 mile) runs and in warmer conditions where foot swelling can be significant. However, technical downhill performance is similarly “just a bit” affected where there is noticeable additional lateral foot movement in downhill grades greater than about 20%. I do a lot of 30-60% grade downhill running so the slightly reduced performance of the S Lab Sonic is definitely a concern for any run or race that has substantial sections of downhill at grades greater than about 20%. But I have also found that I have gotten used to this additional displacement and have had no blister or rubbing issues for continuous steep downhill sections in excess of 4-6 km (2.5-4 miles). I plan to use the S Lab Sonic in an upcoming 60km mountain trail race with long sections of steep downhill so it will be interesting to see what transpires.
There is more “edge of foot” support that leads to a more structured feel for the shoe but at the same time this adds to the comfort particularly on long runs. I find that my feet are not as “tired” after equivalent length runs when compared to the S Lab X-Series. When compared to the S Lab Sense Ultra, the S Lab Sonic is much more comfortable with as good or better trail feel and only slightly reduced grip.
Venting and Drainage
The very breathable mesh used on the S Lab Sonic runs cooler than the S Lab X-Series and, as expected, drains well. I have experienced very good thermal performance up to about 80 F (27C) ambient, a point where the X-Series (with a lycra upper material) would begin to get a bit toasty. The Sonic will likely be a good summer performer.
The Achilles Heel – the Laces
I complained about the fabric laces on this shoe from the beginning and I have not become a convert. Traditional laces are fussy, floppy, and prone to loosening or coming untied altogether. I will admit to never being a good knotsmith (this Boy Scout merit badge was a challenge for me) but I do know how to tie a shoe and these laces will come loose without a double knot- a knot that is a PIA to undue after a 30 km run and your legs are stiff. There have been a couple of incidences of the lace loops catching on the sage around here and one incidence of the laces filling up with tiny burdocks which were also a PIA to get off.
Bottom line- bad choice for laces on the S lab Sonic. However, in Salomon’s defense, the shoe is intended for road and light trail use. I think it would have been a superior choice to ship the shoes with the speed laces and include a pair of traditional laces in the box and give the choice to the user- particularly at a price of $170.
Just as with the S Lab X-Series, the outsole wear is exceptional and at this juncture barley noticeable. I expected a bit more wear as the high wear-rating carbon rubber bits that were used in the X-Series were replaced with “red” rubber. Upon investigation, it may be that these areas (or the entire outsole) has been manufactured with silica particulate reinforced material that allows for similar wear and toughness as carbon rubber but also allows for colorants. In any case, wear is exceptional.
Similarly, the upper has shown very little evidence of wear and it seems that the upper mesh material will be durable- contrary to the excessive wear noted by many users with a similar mesh that is used in the upper on the S Lab Wings (this is something I understand has been improved with the soon-to-be-available S Lab Wings 8).
Cushioning is only slightly reduced at this point, but my experience has found that cushioning loss is not a linear function. It seems that cushioning eventually goes through a dramatic drop at some point and one has to be tuned into this to ensure that impact damage does not accumulate and possibly lead to injury.
I have found the S Lab Sonic to be a slightly improved S Lab X-Series where the improvements have lead to greater comfort, better trail feel, better thermal performance, and enhanced drainage. The use of traditional laces on this shoe is a negative as far as I am concerned.
Stay tuned for a final update in the future.