Sunday, August 30, 2020

Altra Superior 4.5 Review: A Trail Runner for Fast Fun. Improved!

Article by Dom Layfield

Altra Superior 4.5 ($110)


The Altra Superior 4.5 is a minor update to version 4.0.  In this revision, the upper fabric is changed to a (presumably) tougher mesh, and the sole is made slightly stiffer.   The Superior 4.0 was a lightweight, super soft, slipper-like shoe, and version 4.5 retains this same character while making the shoe slightly more mainstream.


  • Retains glove-like fit, and slipper-like feel

  • A hair more midsole stiffness makes shoe more forgiving

  • Grip slightly better


  • A tiny bit heavier than before (+8 g/0.3 oz per shoe)

  • Still too minimal for many

Tester Profile

Dom 48, trains and competes mainly on trails in Southern California running about 3000 miles and 500k ft of vert per year.  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.  2019 was a quiet year, with his only notable finish at the multi-day Dragon Back race in the UK.


Weight: men's 8.4 oz / 238g(US9)  /  women's 7.3 oz / 207g (US8)

  Sample: 9.0 oz / 255 g  (US M10)

Stack Height:  21 mm (official number - not sure if this includes Stone Guard plate)

Available now including Running Warehouse here ($82.50 through Sept 7)

First Impressions and Fit


In my original review, I was delighted with the upper of the Superior 4.0.    It felt exciting and innovative and bold.   The soft, conformable, glove-like fit was a major part of the shoe’s barefoot, natural feel.   My only real concern was durability: the forefoot fabric felt a little flimsy.   

In version 4.5, Altra have replaced the smooth fabric in the forefoot with a coarser mesh that feels like it should be more resilient.   I did worry that the new fabric would admit more dust, but that doesn’t seem to be the case.  In side-by-side testing, I didn’t observe any difference in how dirty my socks or feet were after a hot, dry run.

The other notable change is that the midfoot retention has improved slightly.  I didn’t have any complaints about 4.0, but after wearing 4.5 and comparing the two shoes one on each foot, 4.0 felt sloppier.   


I don’t know exactly what Altra tweaked under the hood, but version 4.5 is noticeably stiffer under the midfoot.   Version 4.0 was so soft throughout that it felt like a ballet slipper.  4.5 increases torsional and bending stiffness, and while this remains a very soft shoe by most standards, the tweak makes the Superior a little more forgiving, and a little more accessible to the mainstream.


Comparing old and new versions of the Superior, I don’t see any obvious difference in the outsole.  As with version 4.0, the outsole rubber is unusually soft.   With version 4.0, I observed that I could feel (or thought I could feel, at least) the lugs folding under extreme loading, which made me slightly cautious on steep descents and aggressive cornering.

Despite no apparent change in the outsole, version 4.5 feels grippier.  My guess is that this is due to the stiffer midsole underneath.   The firmer base anchors the outsole better, and I didn’t notice any of the instability that I occasionally experienced with version 4.0.

That said, this is still not a shoe notable for outstanding traction.   In my opinion, that’s just fine.   It’s like complaining that a screwdriver makes a poor pry-bar.   


When I first hand-flexed the Superior 4.5 and noticed it was stiffer, I worried that -- in their attempt to make the shoe more mainstream -- Altra might have killed the magic that made version 4.0 such a delight to run in.   (Shoe manufacturers are notorious for doing this: they listen to complaints about a shoe, and attempt to ‘fix’ the problem in revised versions.   But in doing so, they alienate enthusiasts of the original without enticing new buyers, and end up with a bland shoe that pleases nobody in particular.)

But on the foot, the Superior 4.5 feels very much like its predecessor.   It is still soft, and nimble and light, with fabulous trail feel.   The extra stiffness makes the new version a little more forgiving and a little more capable.   

There is no ‘right’ answer to how to trade off trail feel and protection: we all have different opinions, and different tastes depending on how much we’re running, terrain, injury status etc.   Personally, I found Superior 4.0 too minimal with the Stone Guard plate removed.   With the insert in place, the balance seemed about right.   The extra stiffness in 4.5 is useful here, as I was able to run comfortably with the shoe in both configurations (plate inserted and removed).

Conclusions and Recommendations:

Bam!   After a period of (what felt like) neglect, Altra are at the top of their trail shoe game.   I’ve recently raved over the King MT 2.0, the Timp 2.0, and the Superior 4.0.

The Superior 4.5 doesn’t change much: it is slightly firmer, and has slightly improved foothold.   This feels very much the same shoe, improved.

Score: 10/10

Altra took an excellent shoe and made it better.

With that '10/10' score, keep in mind that the Superior  remains very much a “strong cheese” (i.e. not for everyone) kind of shoe.   To pursue the metaphor: I think of version 4 as a Roquefort.   Exquisite to a receptive enthusiast, but too smelly for most people.  Version 4.5  tweaks the recipe, to make its appeal more mainstream.   It's now more like a Gorgonzola: not so polarizing, but still a blue cheese, and unlikely to be palatable to consumers accustomed to orange cheddar.

It is light, flimsy, unsupportive flat with an upper fit that some will consider sloppy.   I loved it, but still find that it a shoe best for casual running.   When I’m trying to up my mileage to the limit of what my body will tolerate, I need more shoe than this.   But when I’m not looking down the barrel of an upcoming race, and just want to enjoy my time on the trails, the Superior 4.5  is close to perfect.


Index to all RTR reviews: HERE

Altra Superior 4  (RTR Review)

Discussed ad-nauseam above.  But to summarize here: Superior 4.5 is very similar. The midsole is slightly stiffer, and foot retention is slightly improved.

Superiors old and new: version 4.5 (left) and version 4.0 (right)

Topo Runventure 3 (RTR Review), Altra King MT 2 (RTR Review)

I really struggle to pick a winner here.  These are all favorite shoes of mine.  All similar in that they have a roomy fit, are low (or zero) drop, and have limited support and rock protection.  But all distinctly different.   For softest fit, slipper-like upper, and squishiest sole, go for the Superior 4.5.   For snugger fit, toothiest outsole, and less cushion, and best performance in mud and wet, go for King MT 2.  For a minimal shoe with more conventional feel, go for the Runventure 3.

Superior 4.5 (left) vs King MT 2 (right)

Altra Lone Peak 4.5 (RTR Review)

While Altra have been nailing their trail shoes in the last year or two, in my opinion the Lone Peak is a misfire.   The LP4 introduced a rockplate that made the shoe heavier without any apparent benefit, and the LP4.5 revision did nothing much to help.   It’s still a decent do-it-all shoe, but makes less sense now that the excellent Timp 2 provides more cushion at a lighter weight.   I’m hoping version 5 will reinvigorate the missing space between minimal Superior and and maximal Timp.

Altra Timp 2 (RTR Review)

If you want to stay in Altra-land, there’s a quantum leap between Superior and Timp.   Don’t get me wrong, I’m a huge fan of the Timp 2.  I use mine during periods of high volume training, and  plan to wear them in upcoming 100-mile races.   But it feels like too much shoe for everyday training.

Nike Terra Kiger 6 (RTR Review)

TK6 is a functionally more conventional shoe that Superior 4.  It’s heavier, stiffer, and narrower.  The TK forefoot is fantastic, but it is saddled with a horse’s arse of a rear-end which is incongruously high and stiff.  (Excuse the mixed metaphors.)   Choose Nike for a more conventional fit with more heel-to-toe drop, or if you’re a heavy heel-striker.

Brooks Pure Grit 5

This was almost a shoe that I might have been discussing in the ‘champions’ section above alongside Superior, King MT, and Runventure.   It fits into the same lightweight, unstructured, minimal category.   It is low drop (4 mm), with slightly narrower forefoot.  Underfoot feel is excellent, with a distinctive smooth creaminess, and nice balance between protection and trail sensation.   My problem with this shoe is that the heel collar is low, wide, and with little padding.   With my narrow heels, the shoe gave the constantly distracting sensation of the back end falling off my foot. 

Read reviewers' full run bios here
The product reviewed was provided at no charge for testing. The opinions herein are the authors'.
Comments and Questions Welcome Below!
Please let us know mileage, paces, race distances, and current preferred shoes

RoadTrailRun receives a commission on purchases at the stores below.
Your purchases help support RoadTrailRun. Thanks!

Available Now!
USA  Men's & Women's SHOP HERE
FREE 2 Day Shipping EASY No Sweat Returns
EUROPE Men's & Women's SHOP HERE

Available Now!
Men's & Women's SHOP HERE
Join VIP Family, Get Free Shipping and 15% in VIP Benefits on every order, Details here

 Available Now
Men's & Women's  SHOP HERE!

Available Now!
Men's & Women's  SHOP HERE 

Available Now! 
Men's & Women's SHOP HERE


Please Like and Follow RoadTrailRun
Facebook:  Instagram: @roadtrailrun
Twitter: @RoadTrailRun You Tube: @RoadTrailRun


Curt said...

Good to see you back Dom! I have a few questions. Is there any chance the observed increase in midsole stiffness might just be due to the fact that the 4.5 is a new shoe and the 4.0 is more broken in? Per my conversation with Altra, they should be the same midsole.

Also, any plans on reviewing the TerraUltra G270? I was a bit dismayed to see you weren't on the list of reviewers, and it sounds like it could be your jam. Similarly, I'd be interested to hear your thoughts on Carson Footwear, who use a super basic polyurethane based sole akin to Chaco's. At least, I think they'd be closest to Chaco's.

Anyway, keep up the good work and stay safe!

Telemarker said...

Hi Curt,

Appreciate the 'welcome back' message.

Hmm... you're right. I don't know why I didn't at least consider the possibility that the difference in stiffness may just be due to foam aging/degradation in the older shoe. That's very possible: although if it is the case, it would be the biggest change I've ever seen. When I first compared the shoes (by hand-flexing), I thought that Altra might have added a midsole shank. The difference is striking.

Another possibility is that my pre-release Superior 4's were an early iteration in which Altra were still experimenting with different foam formulations, and I received a pair with lower durometer than the final production shoe. Or that Altra have been quietly tweaking and evolving the Quantic recipe over the intervening 18 months.

I guess I should try to find a local running store (if there are any left alive) that has still has stock of Superior 4 to compare against.

Thanks for the useful input!

-- Dom

Curt said...

Further midsole tweaking is certainly possible. And I suspect there's some manufacturing variance that occurs as well between production runs of various models. Still, I'd be very curious to hear how a fresh 4.0 might compare to the 4.5. Not a big deal if you can't find it though. A slightly firmer 4.0 sounds about perfect to me anyway.

Also, did you try the Vanish XC? I've been eyeing both a new Superior and the Vanish line given the current sales.

Wes Arnold said...

A comparison with the G270 would be good. Both are currently top options for me for speedier trail sessions.

Sam Winebaum said...

Hi Wes,
Soon as Dominick Layfield is going to test G270 and compare.
Sam, Editor

frnkr said...

Hi Dom, trying to choose between Runventure 3 and Superior 4.5. As I tested both of them I noticed that RV3 upper feels a bit "hard" on top of my toes. Did you felt the same (and did it break-in)?

I had high hopes for RV3 as it shared similarities with Terraventure 2 (which I loved) but not sure abt it now... 🤔

Also, thanks for the great review 👍🏻

Michael said...

Hi Dom,

Thanks for the review. I love this shoe, and was wondering if there is a road version that is similar?

Curt said...

Hey Michael,

I'm not Dom, but I'd guess that the Escalante Racer would be the closest fit. At least, it's probably the closest in regards to stack height.

Ronan said...

Hello all,
I got 3 Superiors shoes: two version 2.0 and one version 3.5.
I love the sole of the 2.0, it is very flexible and smooth, the 3.5 is too rigid from my point of view.
How about the 4.5?

Telemarker said...

Hi Ronan,

I don't recall exactly which version of Superior that I first tested but Superior 4.x are *much* softer than version 3.x. If you like soft, flexy soles, you'll enjoy 4.x.

-- Dom

Ronan said...

Many thanks Dom,