Article by Sam Winebaun
ASICS S4+ Yogiri ($200)
Introduction
The limited release S4+ Yogri is ASICS answer to the need for less prescriptive, more stable supershoes for the marathon mid pack.
The 4 “S” stand for "speed, stability, safety, and sub4". It’s a racing (and training) option that recognizes that not all marathoners are “fast”, have perfect form or $250 plus to spend. And that is what ASICS delivers here. Please read on for all the details.
Carbon plated with a deeply plunging soft and reactive top layer of the FlyteFoam Turbo + ( as in the Metaspeed Edge and Paris) towards the ground it has a layer of firmer stabilizing FyteFoam.
Its upper is a smooth, very smooth fitting engineered mesh with a full laminated soft lining.
It has more outsole coverage than most full-on racers at the rear and through midfoot for stability and durability as for sure one can train in the S4 as well as race.
Pros:
A practical and stable super shoe for the non elite: “legal” height and competitive weights
Dynamic rolling toe offs: top flight top layer of soft and responsive FlyteFoam Turbo+
Low mounted plate: no plate harshness, no awkward transitions and at any pace.
About the most stable super shoe yet due to firm lower FlyetFoam layer and outsole
Comfortable all the way: especially broad fitting yet secure upper for a race grade shoe
Solid race choice for broader feet and heavier runners
Reasonable weight (8.1) oz and reasonable price ($200)
Cons:
Dull heel feel: lower layer Flytefoam is quite firm at the heel, reducing bounce there and may also increase weight.
Please find the testers full run bios at the end of the article after Comparisons.
Stats
Approx. Weight: men's 8.15 oz / 231g US9
Stack Height: 40mm heel / 34mm forefoot
Sample Weight: men’s 225g/ 7.94 oz US8.5
Stack Height: men’s 40mm heel / 34 mm forefoot (6mm drop)
Platform Width: 75 mm heel / 65 mm midfoot / 105mm forefoot
First Impressions, Fit and Upper
Clean, sleek, and simple is my first impression of the S4+. No garish neon colors or complicated overall design. They eye immediately focuses on the smooth looking white upper, with light pastel green laces, ankle collar and heel counter overlay. Then towards the off white Turbo+ foam which stands out as deep up front and says energy return and tech to me. Finally to the light pastel green lower FlyteFoam midsole which seems to promise soft landings.
The upper mesh is moderately thin and more continuous and softer than typical race shoes. The softness is accentuated on foot by a very thin inner soft lining throughout the entire interior bonded to the entire interior including the toe box.
I was skeptical given the generous fit and softness, thin tongue and no gusset that there would be enough support but there is plenty of support and comfort for that around 4 hour marathon if not faster and training.
The lace up is smooth and well held by the thin ridge laces that unlike many but like the Metaspeed Paris and are a bit softer and less rigid than some.
The heel and ankle area opening is moderately broad with the padding continuous in that area and not the often seem bolsters in the interior. Again similar to Metaspeed Paris.
The front of the shoe and toe box is quite unstructured beyond a bit of toe bumper stiffening with the mesh more continuous and denser than the Metapeed Paris, remembering also the interior lining which leads to a smooth fit on the foot. Yet hold is excellent if not a total elite focused strap down.
Given the width and pliability and slight stretch of the mesh the toe box should accommodate wider higher volume feet than usual in supershoes. I am true to size with no issues.
Midsole & Platform
The platform width is 75 mm heel / 65 mm midfoot / 105mm forefoot. So we are 5mm wider at the forefoot,10mm wider at midfoot and the same at the heel as the Edge Paris.
The wider midfoot makes S4 more stable (along with more outsole coverage there) while the wider forefoot gives more Turbo + to sink into and rebound and roll forward off of.
The stack height is 40mm at the heel and 34mm at the forefoot so for all intents and purposes the same as the Edge and most supershoes.
We are race “legal” at a 40mm heel unlike the Magic Speed 4, my 2024 of the year which pushes the heel to 43.5mm with about the same forefoot height of 34mm so 8mm drop vs 6.5 mm here. Interestingly the substitution of light softer more resilient Turbo + in the S4 gives it a noticeably more energetic toe off.
Below the Turbo+ in an interesting choice. We have “old school” FlyteFoam.
It is quite firm at the heel compared to Blast+ or Turbo foam and clearly helps give the S4 its leading stability for a super shoe.
I wonder if a slightly softer and lighter Blast+ layer as found in the Magic Speed 4 or deeper softer Turbo+ might offer but clearly ASICS was focused on stability and a steady ride here and the FF delivers that but is a bit dull in an otherwise energetic mix.
The full length carbon plate is low mounted at the front (between the Turbo+ and FlyteFoam), favoring a more rolling stride. It is in a similar location to the plate in the Magic Speed and Edge.
Higher mounted plates such as in Sky Paris favors a more vertical higher knee lift and longer stride. Again, a wise choice to mount the place lower for the intended sub 4 hour focus. I would add, returning to the FlyteFoam lower layer, that is relatively firm below the plate, and seems to better isolate the plate in feel and also in “noise” as there is minimal slapping heard, often the case with low mounted plates, think Vaporfly for example.
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There is a distinct and super pleasant sensation of the foot plunging down and forward to toe off due to the combination of deep soften Turbo + foam then a decisive and stable response from the plate/FlyteFoam/outsole combination
Outsole
Always fine ASICS Grip covers a large portion of the underside of the S4 for increased wear surfaces and stability. Most notable is the full wrap around rear rubber that is not often seen in super shoes as the assumption is the runner is landing further forward at elite or near elite paces.
I think it is a bit overdone and may contribute, along with the FlyteFoam just above, to some of the firmness and moderate shock transmitted on landing even if the rear is very well cushioned. The rear of the shoe, as a result, is not particularly bouncy.
I think a deeper central decoupling groove might help spread forces and soften some or ASICS might consider a deeper top Turbo+ layer at the rear. That said, the rear is very very stable and substantial and because the top Turbo+ foam is soft, cushioning at initial landings is fine if a bit old school firm.
Ride, Conclusions and Recommendations
S4 stands for “speed, stability, safety, and sub4 and that is exactly what the S4+ delivers. If I was to pick one of the S’s to highlight it would be stability and to a fault almost as the lower FlyteFoam layer is quite dense and firm, the shoe will not leave you wobbling, back on the heels or unable to transition pretty much no matter your race pace. I would like to see a slightly softer (maybe lighter) lower layer of foam.
Coming back from knee issues, most of my testing to date has been in the 9:30-10:30 minute mile paces and I found the shoe became effective and smooth below 10 minutes miles. So the 9:09 minute miles which deliver a 4 hour marathon should for sure be in its sweet spot as well as faster times.
It also is an excellent choice for any pace racer seeking more than the usual stability in their super shoe, if the course is particularly hilly, or you have a higher volume foot which has struggled with typical super shoe fits.
I particularly enjoyed the forefoot of the shoe with the soft plunge into the Turbo + foam then th eenergetic smooth toe off, well stabilized by the plate and thin lower FlyteFoam layer.
It for sure also fits the bill as a training shoe for faster tempos. The Magic Speed 4 with its higher stack height and similar plate location was my 2024 shoe of the year for its versatility as a trainer and here given the lower stack the S4 leans more racing than the Magic.
I would consider it a solid value when one also considers its not exceptional but reasonable 8.15 oz / 231g US9 weight, full super shoe 40/34 stack height, $200 pricing, comfortable secure yet more “relaxed” race type upper, and copious fuller rubber coverage one gets a versatile racer that can also be used for many miles of faster training.
Sam’s Score: 9.3 / 10
All deductions are for the lower firmer FlyteFoam layer and rear geometry. A lighter more energetic foam or more landing decoupling there and without compromising stability too much, would be a meaningful improvement.
😊😊😊 1/2Comparisons to come after more refresher runs in similar shoes.
Tester Profiles
Sam is the Editor and Founder of Road Trail Run. He is in his 60’s with 2025 Sam’s 53th year of running roads and trails. He has a decades old 2:28 marathon PR. These days he runs halves in the just sub 1:40 range if he gets very, very lucky. Sam trains 30-40 miles per week mostly at moderate paces on the roads and trails of New Hampshire and Utah be it on the run, hiking or on nordic skis. He is 5’9” tall and weighs about 160 lbs, if he is not enjoying too many fine New England IPA’s.
1 comment:
I've followed this blog for almost a year now, and you guys always write good quality reviews and catch some details that others don't. Your reviewers are good at keeping their subjective experience in check and not writing off shoes based on a personal opinion of them, too. Keep up the great work.
I think this article, however, highlights a need for grammar checks. There are a lot - as in a lot-lot - of spelling errors and slightly incoherent sentences in this review. Could be a nice improvement looking forward. Thanks for the reviews!
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