Article by Jeff Valliere and Sam Winebaum
Scarpa Spin Infinity ($149)
Introduction
Sam: The Infinity is Scarpa’s most cushioned current trail and ultra shoe and the shoe that was on the feet of Aurélien Dunand-Pallaz for 2nd at the 2021 UTMB. This fact had me sit up right away and wanting to test as a UTMB podium shoe has to be capable of tackling any surface, tremendous vertical and many hours of running.
Scarpa, an Italian brand is well known for its climbing, hiking and ski mountaineering shoes and boots and with the Spin line has created trail running shoes that are not clearly not “variants” of footwear for those other activities in any way but are pure trail runners top to bottom.
It has a 35mm heel (measured), 31mm forefoot (spec 4mm drop) and weighs 10.9 oz / 309g in our US9/EU 42 sample so it is on the heavier side but this said only 0.2 oz more than a Speedgoat 4.
The midsole is a dual density compression molded EVA with a firmer outer perimeter and arch and a lower density softer center core, an approach in trail and road shoes we see in 2021 becoming more common.
It has a full coverage 4mm lug Vibram MegaGrip compound outsole in a Velox Cross pattern. There is no rock plate and we’ll say it right up front none is needed and the omission helps lead to a nicely agile “big” shoe with some front flex.
Pros:
Jeff V/Sam: Cushion, protection, traction, secure fit, comfort, agility, response
Sam/Jeff V: All around protective and fun to run choice if weight is not a primary consideration
Sam/Jeff V: Maximal and forgiving cushion without a lumbering feel
Sam/Jeff V: Superb any surface outsole. Even some road is OK here
Sam/Jeff V: Trail to door capable if more trail than road.
Cons:
Jeff V/Sam: Weight (though runs a bit lighter than measured weight might suggest)
Sam is the Editor and Founder of Road Trail Run. He is 64 with a 2018 3:40 Boston qualifier. Sam has been running for over 48 years and has a 2:28 marathon PR. These days he runs halves in the just sub 1:40 range training 30-40 miles per week mostly at moderate paces on the roads and trails of New Hampshire and Utah. He is 5’9” tall and weighs about 164 lbs if he is not enjoying too many fine New England IPA.
Dom 49, trains and competes mainly on trails in Southern California. In 2017 he was 14th at Western States 100 and in 2018 finished 50th at UTMB and 32nd at the 2018 Los Angeles marathon in a time of 2:46. In 2019, his only notable finish was at the multi-day Dragon’s Back race in the UK. All 2020 plans were wrecked by Covid and California forest fires. In 2021, he’s trying to inch his way back to racing!
Jeff runs mostly on very steep technical terrain above Boulder often challenging well known local FKT's.
Stats
Weight: men's 10.9 oz / 309g US9/EU 42 sample 9 oz. / 255g women's / (EU38)
Samples: men’s 10.9 oz / 309g US9/EU 42 sample, 11.4 oz / 324g US10
Total Stack Height: 35mm heel (measured), 31mm forefoot (spec. 4mm drop)
Available November- December 2021. $149
First Impressions and Fit:
Jeff: The Spin Infinity out of the box looks impressively modern, well built and ready for all mountain use with a protective upper, significant midsole and aggressive tread. Initial step in comfort is excellent, with a well padded feel, deep, yet firm cushion and a secure fit. I like the lacing, lace garage, gusseted tongue, durable quality construction and eye-catching sporty blue colorway.
Fit is true to size and overall feels just right for my narrow, low volume foot. For an ultra distance shoe, some may find the toe box to be less than roomy for splay and swell and I think sizing up a half size for those with slightly wider feet, or those with just a preference for a bit more wiggle room would be a logical choice.
Sam: My pair is half a size up from my normal US8.5 at US9/EU 42 and I would stay there if running with thicker socks or expecting swelling as the combination of the stout stretch gusset tongue and relatively narrow toe box makes for a relatively low volume fit.
At half size up I am secure and comfortable. My feet are medium to low volume. I might go true to size if wearing thin socks. On the foot, one is struck by an unmistakable sense of upper security and hold that says bring on more technical terrain. The underfoot feel is relatively firm and very stable but with some bounce and give telling me the ride will be forgiving enough for any distance and for firmer terrain (and even road) and lively enough to go fast despite the relatively high weight of 10.9 oz / 309g in my US 9 sample.
Of course the bright aqua blue color is striking and fun!
Upper
Jeff V: The upper consists of what Scarpa describes as Mesh and PU Film and Micro Nubuck, which is a breathable mesh with overlays of thermally welded PU film for additional protection, support and abrasion resistance along with and midfoot suede underlays tied into the lacing. I find this upper to strike an exceptional balance of protection, flexibility, security and breathability.
The tongue is gusseted and moderately padded with a stretch fabric incorporated with the tongue that provides a comfortable wrapped feel, added support and enhanced fit.
The lacing is very precise with an easy one and done secure snugging of the midfoot. I find the lace garage to be handy, but a touch shallow.
The heel counter is slightly semi flexible, well structured and secure, with nice comfortable padding around the heel collar, and is not overly built.
The toe bumper is beefy and protective, without feeling noticeable or obtrusive, integrating with the overlays for added protection and a continuous wrap around.
Breathability is good, at least I have found the Infinity to be reasonably cool on days in the 80’s F, yet not so airy as to be uncomfortably drafty on colder (dry) runs in the mid 20’s.
Sam: Jeff has described the upper well. This is an elaborately supported upper with essentially a cage of overlays and underlays covering the soft and supple main mesh. The resulting cage of support is nowhere stiff and wraps the foot smoothly and very effectively. While the gusseted tongue is snug and there are all those overlays this is a very comfortable shoe. So comfortable that I also enjoy wearing them day in day and out off the trails.
My only area of concern is the X shaped overlay at the ball of the foot. While it is super effective in locking down the front of the foot (along with toe bumper) around the soft mesh those with wider feet or bunions may find a touch of pressure here. I did initially but the shoe has since stretched out.
Midsole
Jeff V: The Dual-density compression molded EVA with Scarpa’s Foot Stabilizer Control System is of a medium density for stability, torsion control and a low density base for max cushioning.
Scarpa describes it best on their product page -
“Designed for long distance trail training and ultra racing, the Spin Infinity has a dual-density EVA midsole, featuring a low density base that provides plentiful cushioning and impact absorption, and on top of that is our Foot Stabilizer Control system (FSC). The FSC system is a firmer EVA layer that encircles the perimeter of the midsole and also spans the arch area, providing lightweight stability and torsion control. The midsole's 4mm drop encourages an efficient stride, further enhancing its long distance capabilities.”
I find the Spin Infinity to provide a very well balanced combination of deep cushioning while maintaining a firm, responsive and predictable feel. While not a dedicated speedster, I find response to be very good for such a maximal shoe and is ideal for all day adventures on just about any terrain. While cushioning is moderately firm, shock absorption is excellent, especially on long downhills and on hard surfaces. My legs never feel beat up. Stability, predictability and protection are all top notch. The absence of a rock plate goes unnoticed given the quantity and quality of the cushioning, while maintaining good overall flexibility. The Spin Infinity has a high riding feel, but I have never had any trouble with stability, even when running fast through rocky, technical terrain.
Sam: A superb midsole package here of dual density compression molded EVA foams. The outer firmer cage provides stability and torsional rigidity while the softer inner and underfoot core (black above) provides a softer feel and forgiving cushion. Both densities are very well blended together so there is no feel overly rigid stabilizing, center mushiness, or instability. As such, the midsole package is versatile. I have run semi technical trails, single track, dirt roads and pavement and the Infinity is competent and forgiving on all terrain. To compare I would say the midsole feel sits squarely between Saucony’s EVA/TPU blend PWRRUN and their all TPU PWRRUN+. It is for sure more forgiving than Salomon’s Energy Cell+, less dull and dense than Optivibe, and not as soft and bouncy as Energy Surge.
Outsole
Sam: The outsole is Vibram MegaGrip in a Velox Cross pattern. The coverage is almost full with just two small windows to the midsole near the heel.
This is one versatile outsole. It combines 4mm lugs with wide rock gripping and pavement forgiving larger contact surfaces in a quite open pattern for weight reduction and mud dispersion.
The mid foot has more continuous rubber for stability.
While not flexible up front the wide spacing and some very shallow flex grooves keep the toe off smooth and fluid everywhere.
Jeff V: Sam describes the outsole well. I am surprised at the reported 4mm depth of the lugs, as they seem more substantial and perform more like 5mm, which is a testament to their effective design and arrangement. I have run on just about every surface except for ice and snow and they are very versatile and grippy. From steep, loose off trail, to rocky technical trails, slabby rock scrambling, the outsole design and compound has never let me down. I have not run in them on a truly wet day, but have found some wet sections or rocky creek and they seemed to hold well. Durability has thus far has proven to be above average.
Ride
Sam: A wonderful “big shoe” ride which combines tons of forgiving enough cushion, plenty of stability, and smooth any angle or surface toe offs. You will not mistake the ride here for a light speedster given the weight of 10.9 oz but for the amount of protection and substance with just enough bounce and lively feel your feet and legs will be very happy hour after hour at any pace and on any surface. It even has a more than decent road ride so it can be a great option for door to trail with emphasis on trail as I found out on several runs.
Jeff V: Sam sums up the ride perfectly. While not a light or dedicated speedster, that is not what the Spin Infinity is trying to be, but instead is a relatively lively, well cushioned, versatile, protective shoe that can easily transition and adapt to just about any pace or terrain and do it very well.
Conclusions and Recommendations
Sam: The Infinity joins its 2 siblings the Spin 2.0 the lower slung fast speedster and the Spin Ultra as the heavy duty long hauler in the line up. It is a versatile and protective option if you seek big cushion, a lively ride, and plenty of grip and protection. The blend of elements: secure upper, forgiving yet stable midsole, versatile outsole, and lively enough geometry come together very well to deliver a great all around option that can tackle just about anything you throw at it.
While on the heavier side, its attributes have it riding lighter than its weight although I do wish it could check in closer to 10 oz / 283g than the current 10.9 oz potentially be simplifying the upper and reducing the outsole coverage a little (rubber being the heaviest material in a shoe) . If you are not a gram weenie, go long including ultras, or seek a versatile, durable all around trail runner, hiker, and just darn comfortable shoe day in day out it is a top 2021 choice for me in those categories.
Sam’s Score; 9.49 /10
Ride:9.4(30%) Fit:9.3(30%) Value:9.6(10%) Style:9.3(5%) Traction:9.8(15%) Protect:9.8 (10%)
Jeff V: Agreed with Sam again, this is one of my favorites in the max shoe category for 2021. The Spin Infinity has been a go-to pick for just about all trail runs lately (at the expense of other shoes I still need to test more miles in), as it just fits the bill for a well protected, lively, versatile daily trainer with great traction, cushion and protection. I can see how it was an appropriate pick for the front of the pack at UTMB.
Jeff V’s Score: 9.6/10
Ride: 9.5, Fit: 9.5, Value: 9.5, Style: 9.5, Traction: 9.5, Rock Protection: 10
Comparisons
Index to all RTR reviews: HERE
Scarpa Spin Ultra (RTR Review soon)
Jeff: The Ultra has a bit more substance underfoot, though it is actually 1 gram lighter than the Infinity. That said, I find the Ultra (which is a few years old now) to be less responsive, less agile and feels a bit heavier. None of this is a knock on the Ultra, but just a nod to how good the Infinity is.
Scarpa Spin 2.0 (RTR Review)
Sam: The Spin 2.0 is the shorter distance fast and agile sibling to the Infinity. Its midsole is a blend of PEBA and EVA which reduces weight and provides a lively ride with a surprising amount of cushion. It weighs about 2 oz / 57g less but gets close in cushion and protection to the Infinity, It even has a front hardened ESS rock plate. It has a similar upper and somewhat more performance oriented fit. If your trail runs are shorter or you prefer an agile speedster with plenty of protection and cushion it is the clear choice. If you lean towards more max in cushion and protection or run long and technical Infinity.
Salomon Sense Ride 4 (RTR Review)
Jeff V: I find the Sense Ride 3 or 4 to be less protective underfoot and not as good loose traction, less cushioned and not as lively as the Spin Infinity, but the Sense Ride perhaps a bit more comfortable with more versatile/flexible relaxed (but still snugging nicely) upper.
Saucony Peregrine 11 (RTR Review)
Jeff V: The Peregrine has deeper tread better for more loose terrain (though I have not yet struggled in the Spin Infinity), comparable underfoot protection, comparable fit, better lower to the ground confident stability, but the Spin Infinity has a more stack and cushion for longer outings and/or extended downhills particularly on hard surfaces. Peregrine for shorter, faster more technical (though has plenty of substance for all day use) and Spin Infinity for dedicated longer distances or extended downhills.
Saucony Xodus 10 or 11 (RTR Review)
Sam: A full ounce heavier the TPU midsole Xodus is somewhat softer and bouncier with a more energetic feel but its weight is felt in comparison to the Infinity.
Jeff V: Like Sam says, the Xodus is livelier, but there is a weight penalty. All around performance and usage though overlap heavily.
Hoka Speedgoat 4 (RTR Review)
Jeff V: The Speedgoat feels taller, wider and more soft plush, while still retaining surprising agility and performance. I find the Speedgoat to be a bit more lively and fun to run in, but I am really splitting hairs, as both shoes are amazing. Traction and tread wear are comparable, though I would say the Spin Infinity has a bit better underfoot protection.
Scott Kinabalu Ultra RC (RTR Review soon)
Jeff V: The Kinabalu Ultra RC is lighter, more responsive and I would say a more sporty, performance oriented shoe, though cushioning and protection is not on par with the Infinity, so better for perhaps 50k, vs. the Infinity would be a more logical choice for 50+ miles.
Topo MTN Racer 2 (RTR Review)
Sam: Somewhat less cushioned with a lower overall stack height, and lighter by 0.5 oz, the MTN Racer 2 also has a dual density foam midsole and a MegaGrip outsole. It is more nimble and for sure has a more accommodating toe box but for long long outings on rough terrain the Infinity is a better choice while for somewhat shorter faster runs or if you need more front room the MTN Racer 2 is a better pick.
Jeff V: What Sam said above. I would also state that the MTN Racer 2 has a superior outsole.
ASICS Trabuco Max (RTR Review)
Sam: Both shoes have a rigid profile sole with the Max totally rigid and the Infinity having a touch of flex. They have comparable very protective cushion with the Max slightly more cushioned and protective at the forefoot but stiffer. The Trabuco Max is smoother flowing on more mellow terrain given its more pronounced rocker while the Infinity is a superior choice on more technical terrain. Both have excellent outsoles.
Jeff V: Agreed with Sam and will also concur that the Infinity is much more adept in technical terrain, as the stiffness and rigidity of the Trabuco Max can be a liability on rocky, uneven terrain, especially if trying to move fast.
VJ Ultra (RTR Review)
The VJ Ultra is much lighter, faster/responsive, with the fit even more precise and locked in. It has superior traction, but does not offer nearly as much protection, cushion or durability as the Infinity.
Brooks Cascadia 16 (RTR Review)
Jeff V: The Cascadia 16 is very close in weight, traction, overall intended use, durability and protection. The Spin Infinity has more stack height and cushion, but you would be hard pressed to notice a difference. Cascadia has an 8mm drop, vs. 4mm for the Infinity and the Cascadia has a more accommodating toe box for wider feet or preference for foot swell/splay for longer distances, without compromising security.
Brooks Caldera 5 (RTR Review)
Jeff V: The Calera 5 is a little lighter and has a softer, more plush midsole and offers a pillow-like dreamy feel on moderate to less technical terrain. While the Caldera 5 can handle technical terrain just fine, it’s lesser traction and more casual design makes it an ideal any distance cruiser for door to trail and less technical trails, where the Infinity can better handle more technical and rough terrain.
Tested samples were provided at no charge for review purposes others. RoadTrail Run has affiliate partnerships and may earn commission on products purchased through affiliate links in this article. These partnerships do not influence our editorial content
EUROPE Men's & Women's SHOP HERE
AUSTRALIA Men's & Women's SHOP HERE
AMAZON Men's & Women's SHOP HERE
24 comments:
Hey Jeff,
How would you compare it to the Akasha II?
Hi Aaron, unfortunately, I have not yet run in the Akasha II, but reminds me, I need to see if they have my size yet. Thanks for the reminder and I will report back if I get a pair.
Hi Jeff, My Xodus 10 are near 400 miles so looking for another daily trail running shoe. The Scarpa Spin Infinity looks intriguing, but wondering how you think it compares to the Salomon Ultra Glide.
Hey Chris,
Both are great shoes. I find the Ultraglide to be lighter and more responsive, good on technical terrain, but not ideal for it. The Infinity might be a better choice if you consistently run on more rocky, technical terrain because of better durability and protection, though the Ultraglide has a more accommodating toe box.
Could you please compare this Spin Infinity to the VJ Ultra? Fit, cushion, performance, toe box room, etc.
Thanks
The VJ Ultra is much lighter, faster/responsive, fit even more precise and locked in, with superior traction, but does not offer nearly as much protection, cushion or durability as the Infinity.
Mentioning weight seems to be the trend in shoe reviews these days, the Spin Infinity weighs under 330 gr. in my US10, I don't think this is even a minor problem for the majority of runners. Basically there are only a few who can run Ultras in a much lighter shoe Like the Inov8 Terraultra G270...
Unknown, agreed, listing the weight though is common reader/consumer question/concern. Weight on the scale is one metric, but I have had ~11 oz. shoes run much lighter, so it is hardly a factor, yet other shoes the same weight feel like bricks. I always try to be up front with this and as I always say as an analogy, sure, a tricked out 15lb carbon road bike is pretty sweet and fast on roads, but can it hold up to miles of gravel and washboard? Technical trails? Most definitely not, so some weight gain is necessary. If I ever mention weight as a con, like in this case, it could mean that some people may see it as such depending on their needs, or could be a con in comparison to other shoes it competes with in it's class, that does all the same, just is lighter. Thanks for reading!
Can you guys tell if euro 45 is 29cm; and if the upper front is stretchy like a Pegasus trai; I am a widefoot runner;
Unknown, unsure on size conversion, maybe check their website or google? If you have a wide foot, the Peg has more room in the forefoot and a more forgiving upper.
Jeff, thanks for explaining, I totally agree...I just feel some runners compare apples and oranges up to a certain point, leaving also different presumptions like weight of themselves, running Economy etc. behind...
Thank you very much for the reply Jeff!
Hi, how would you compare them to the Salomon S / Lab Ultra 3? What are the pros and cons of choosing one or the other?
Thank you.
I would say the Spin Infinity has more protection and better cushioning, though is not quite as light. Both seem equally responsive though and overlapping usage.
Hi Jeff,
Would this shoe be good for an overpronator or would the TOPO Mtn Racer or another shoe be a better shoe. Thanks.
Hi Unknown, I am honestly not sure here, but think perhaps the Topo may be a little more stable/wide which may help some. Sorry I don’t have a more definitive answer.
Hi Jeff, how does it compare to the La Sportiva Akasha 2?
Thank you
Anon, I find the Infinity to be a bit softer underfoot, more responsive, lighter feeling (despite being close in weight) and just overall more fun to run in, though would give the Akasha 2 a better traction score (not that the Infinity lacks though).
Hi Jeff, is there an Akasha 2 Multi-Tester review in the way ? Not much to find out so gar, especially if v2 is a much different shoe...
Unknown, yes, John Tribbia reviewed the Akasha 2 back on October 5th and I was recently able to obtain a pair in my size (limited samples early on) and just added in my contributions a few days ago in fact.
https://www.roadtrailrun.com/2021/10/la-sportiva-akasha-ii-review-for-long.html
After close to 100 miles I think I can give my impression and I disagree quite a bit with the review. I also run the Spin Ultra and prefer the Ultra by a wide margin, even if overkill in protection in easier trails. I think the Infinity runs heavy and is getting hot, the shoe keeps me plodding along and picking up the pace seems quite an effort. In top of that the shoe needs 50km to get Beinen in, before my feet Hurt because of the stiffer feel. I think the Spin Ultra is much more streamlined and the faster shoe. Maybe in very technical terrain the Infinity can shine, but for the more runnable stuff, I would grab something else. This is of course my personal take only, but at least for me it's not the more runnable Spin Ultra as expected. Greetings from Germany, Ingo
Thanks for the input Ingo, always interesting to hear an alternative perspective.
Actually I bought this based on your comparison with my beloved SG4.
After around 100kms I love them. They don't look very cushioned but they are indeed very cushioned. The underfoot protection is better than the SG4 and they are much better crossing the leftovers of snow in the Swiss Spring (where you need to stick the outside of your shoe in the snow for stability and traction and the SG4 looks like a inflatable mattress). And as an ultra shoe should be, it works for any type of trail and condition you might find during a long race. Snow, rain - mud, rock, etc..
I am actually running the Eiger Ultra Trail on them instead of the SG4 (I might be changing midway to the Mafate Speed 4 in case my feet are in too tired).
Thanks again for this amazing reviews and comparisons !
Thanks Pedro! Kind words are much appreciated. Have a Fast & Fun run at Eiger Trail. Sam Editor
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