Tuesday, March 26, 2024

Altra Running Mont Blanc Carbon Review 6 Comparisons

Article by Dom Layfield 

Altra Running Mont Blanc Carbon ($260)


I’ve long enjoyed running in Altra shoes.  Whether or not you buy into the notion that zero-drop is somehow innately ‘better’, I’ve never liked high drop shoes, particularly for trail use; and mostly, I enjoy the variety.  Disappointingly, though, it’s been many years since Altra have made a shoe that I’ve considered raceable.  Racking my brain, I think the last Altra I raced was the Lone Peak 3.  I still run frequently in Altras, but only for training.

Accordingly, when Altra announced the original Mont Blanc in spring 2022, I was thrilled: finally this felt like a shoe that was explicitly designed for racing, and specifically for the kind of distance and terrain that I prefer. (For the uninitiated, the shoe was named after the 100-ish mile UTMB race that loops around Mont Blanc in France/Italy/Switzerland.)  

While I’m aware that some runners liked the shoe, I personally found it a major disappointment.  On the positive side, the underfoot feel was a delight.  But the weight of the shoe was unimpressive, and more notably, heel retention was terrible: the back end of the shoe felt like it was falling off my foot.

I was advised that the subsequent BOA variant would fix the heel issue, but my experience was that it was minimal improvement.  I didn’t trust the shoe enough to wear it in a 100-mile race, and when I did finally use it in a 50-miler in December 2022, a large portion of the course was sticky mud which literally pulled the shoes clean off my feet several times.  I never used them in another race.

Fast forward to 2024, and my two biggest questions for the new Mont Blanc Carbon were: (1) have Altra fixed the heel retention?  And (2) is the weight competitive for a race-focused shoe?  I’m glad to report that the answers are ‘yes’ and ‘yes’.  The Mont Blanc Carbon, while not perhaps a standout for heel hold, feels like a normal shoe.  I have narrow heels and didn’t experience any feeling of the shoe falling off.  And the weight is reduced by about 50 g per pair, nearly an ounce per shoe, in my samples (size US M10).  Hoorah!

The new shoe feels fast and light, and fit is much improved.  This feels – finally – like a properly debugged shoe from Altra.  


Impressively light.  

Mainstream last should work for most foot shapes.

Good-looking and distinctive shoe.

Carbon plate doesn’t kill ground feel.

Ready to race!


Cost.  At $260, this is an expensive shoe.

Not as wide as most Altras: fit may disappoint wide-footed runners.  

Benefit of carbon-plated shoes for trail use is still unclear.

Zero-drop shoes remain controversial.

Comparable shoes:

  • Hoka Tecton X 2 

  • Saucony Endorphin Edge

  • NB FuelCell SC Trail

  • TNF Vectiv Sky

  • TNF Vectiv Pro

  • Nike ZoomX Ultrafly

  • Craft CTM Ultra Carbon Trail


Approx, Weight: men's 9.15 oz  / 259ng (US9) 

 Samples: 273 g / 9.63 oz (US M10) ( v1: 10.1 oz / 297 g US M10)

Stack Height: men’s 29 mm heel / 29 mm forefoot (confirmed with informal measurement of sample shoes)

Platform Width: 87 mm heel / 73 mm midfoot / 116 mm forefoot (US M10)

Compared to original Mont Blanc: 99 mm heel / 82 mm midfoot / 120 mm forefoot (US M10)

$ 260 Available now

First Impressions, Fit and Upper

As discussed above, I came to the Mont Blanc Carbon familiar with the highs (sublime underfoot feel) and lows (lack of heel retention) of the original Mont Blanc.  Accordingly, I was delighted to find that the new Carbon version felt refreshingly normal.  Heel retention, while still not stellar (these would not be my first pick for shoe-sucking mud) is so much better that I consider the sloppy heel fit issue fixed. 

The forefoot is a little narrower, slim by Altra standards – which may disappoint Altra die-hards – but the forefoot fabric has a decent amount of stretch to it, allowing the shoe to accommodate a range of foot shapes.  Realistically, the narrower last will suit a wider audience of runners and is more in keeping with the shoe’s role as a “race shoe”.

Notably, weight is also significantly reduced.  The previous Mont Blanc was very average among trail shoes, with my sample pair weighing 297 g per shoe (size US M10), and did not really feel like a race shoe.  The new carbon-plated shoe weighs 273 g, a drop of 24 g (0.85 oz) per shoe.  This weight drop and a weight of 273 g / 9.63 oz in my US10 instantly moves the shoe right into contention with the lightest 100-mile shoes available (e.g. Hoka Tecton X 2, Salomon Genesis, Saucony Endorphin Edge).

Part of weight drop may be attributed to a general slimming of the shoe, which is narrower from front-to-back, losing the flared outsole of the original Mont Blanc.  I see this as a significant win: I’ve never understood why shoe manufacturers seem to think trail shoes should have extra-wide flared soles.  In my experience, this just makes the shoe more prone to catching on irregularities underfoot, and is only (and debatably) beneficial for runners with compromised gait on the smoothest of trails.  Whether or not you fully agree with this opinion, the narrower profile is definitely more in line with the MB Carbon’s positioning as a race-day shoe. 

Heel of Mont Blanc Carbon (right) is much improved over the original Mont Blanc (left), which most runners found unacceptably loose.

Apart from the improved heel retention, the upper is otherwise broadly similar to the original Mont Blanc.  The back end of the shoe uses the same lightweight, and surprisingly durable, translucent mesh on the exterior, reinforced with a suede-like underlay/lining fabric.  Similarly, the front end of the shoe is wrapped in a soft, stretchy fabric.  In the new ‘carbon’ version, the fabric feels a little thicker than before, and a toe bumper overlay has been added.  The lacing has been changed, too, from round ‘paracord’ laces feeding through loops connected to the underlay, to a more conventional arrangement with flat laces feeding through reinforced holes in the upper.

New Mont Blanc Carbon (right) lacing is more conventional than original MB (left).  Laces are now flat, with regular eyelets, and not extending so far down the vamp.

Another welcome change is the addition of reflective material in the heel of the shoe and lacing overlays. From a safety point of view, adding reflective elements to a shoe is a no-brainer: All shoes should incorporate reflective elements, whether or not they are intended for trail use.

The gaiter trap at rear of shoe is now reflective.

Midsole & Platform

While the Mont Blanc carbon looks visually similar to its predecessor (particularly the ‘maroon bells’ color scheme of the BOA version), the new shoe feels different to run in.  For me, the highlight of the original Mont Blanc was the plush underfoot feel.  The Mont Blanc Carbon is firmer, and the plate does lessen the ground feel, but not as much as I expected.

That said, the carbon plate (Carbitex™-branded) sandwiched in the midsole is surprisingly flexible.  It is much less stiff, for example, than the Hoka Tecton X 2’s set up.  It is a little less stiff than the New Balance Fuel Cell SC Trail.  Of all the plated trail shoes I’ve tried, the Mont Blanc Carbon has the least intrusive stiffening plate, the best ground feel, and also has delivered the fewest ‘nasty surprises’ where my foot launches unexpectedly off bumps.

Rough ranking of plated shoes (that I have on hand) from stiff to flexible: Speedland GS:TAM >> Hoka Tecton X 2 > Saucony Endorphin Edge > New Balance Fuel Cell SC >  Altra Mont Blanc Carbon.   Even as I write this, though, I realize that ranking in torsion would be slightly different.

The downside of this flexibility, presumably, is that there is less benefit in mechanical efficiency provided by the plate.  Short of testing on a treadmill in a laboratory, it’s hard to assess how much improvement in efficiency a plated shoe provides, and thus the increment in maximum speed sustainable.  Personally, I’m skeptical that the plated shoes provide a useful mechanical benefit: while there may be a slight upside at high speeds (~7 min/mile or faster) on very smooth trails, that is counterbalanced by reduced ground feel, and less sure-footedness over rough terrain.

What is clear, however, is that – by distributing stress concentrations – a plate allows a shoe to provide more rock protection with less midsole volume, ultimately leading to a slightly lighter shoe. 

When comparing the feel of new MBC to the original (running side-by-side with one shoe on each foot), the two did not feel as different as I expected.  The carbon plate is surprisingly unobtrusive.


The Mont Blanc Carbon has a Vibram™  MegaGrip™ Litebase™ partial-coverage outsole.  Compared to the original Mont Blanc outsole, there have been minor tweaks to add a little more coverage under the forefoot and heel.  I didn’t really have any criticisms of the previous outsole, and found the MBC outsole similarly excellent.

The Mont Blanc Carbon outsole is tried-and-tested Vibram MegaGrip, which is reliably great in all conditions.  Lugs are on the shallow side, consistent with MBC’s race focus.  (I measured typical lug prominence around 3.5 mm.)  This shoe is not going to perform well in challenging conditions like wet grass, mud, or slushy snow.  But traction is very solid 99% of the time, and for a race shoe, I’ll take the weight savings and smooth ride.

Altra Mont Blanc Carbon (top) compared to original Mont Blanc (bottom): the new shoe is slimmer throughout, especially in the heel.  Outsole pattern is tweaked slightly, increasing coverage under the forefoot.

Ride, Conclusions and Recommendations

The ride of the Mont Blanc Carbon is smooth and refined. I’m typically not a fan of plated shoes, especially for training runs, because of the diminished ground feel and potential for unexpected bounces off bumps.  However, the plate here is more flexible than most, and moreover the shoe is not overly stiff in torsion: Which is to say mostly that the feel of the shoe is not completely dominated by the plate.  I found the MBC to be impressively surefooted and highly competent over a wide range of terrain and conditions.

Mont Blanc Carbon testing in Lyngen, Norway, north of the Arctic Circle!

Of all the carbon-plated trail shoes that I’ve tried, the Altra Mont Blanc Carbon is my favorite to-date.  The shoe feels light and fast, yet also cushioned and protective.  Refreshingly for Altra, the shoe feels fully tested and debugged.  It has been many years since Altra have released a shoe that I’ve wanted to wear in a race, but finally, I think they’re back in the game.  The Mont Blanc Carbon lives up to its name: I’m impressed enough that I plan to use these in my next 100-miler.

The only real downside – and it’s a big one – is the price.  With a MSRP of $260 USD, the Mont Blanc Carbon ain’t cheap.  And notably, it’s more expensive than rivals Hoka Tecton X 2 ($225), New Balance FuelCell SC Trail ($200), Saucony Endorphin Edge ($200).   It is, at least, slightly less than the Speedland GS:TAM ($275 + $35 for carbon plate).

Smiles: 😊😊😊😊😊

6 Comparisons

Hoka Tecton X 2  (RTR review)

I’ve worn the Tecton in many hundred-mile races.  The principal reason is because this shoe hits a high point in terms of protection to weight, while doing everything else right in terms of comfort, foot retention, grip, durability etc.  I remain skeptical that the plate provides much performance boost, at least at the sluggish speeds that I’m going.  My only real criticism of the shoe is that the rear of the carbon plate is too wide, and occasionally I find my heel launches unexpectedly off-center bumps.  (I would prefer that the plates formed a ‘Y’ shape instead of an ‘X’.)

Compared to the Mont Blanc Carbon, the Tecton X 2 is significantly stiffer in flexion and torsion and feels firmer underfoot.  MBC is generally softer, with a better ground feel.  Nominal stack height for Tecton X 2 is 38/33 mm, 5 mm drop (although my measurements are about 37/30) compared to 29/29 mm for MBC.  Shoe weights are essentially identical (within 1%).

New Balance FuelCell SC Trail (RTR review)

For me, the FuelCell SC Trail was a near miss.  While there was something magical about the plate-foam combination – the shoe felt like a road super-shoe, slick and speedy on flat, smooth ground – on trail, it just didn’t live up to its promise.  I felt overly tipped forward in the shoe, and found the upper was not supportive enough to stop my foot sliding forward into the narrow, pointy toe box on steep descents.  I should note, however, that other RTR reviewers liked the shoe more than I did.

FC SC Trail stack height numbers differ from different sources: RTR review says 31/21 mm (10 mm drop); Running Warehouse says 36.5/26.5 (10 mm drop).  My hand measurement suggests a slightly larger drop, ~34/22 (12 mm drop).   Compared to Altra MBC at 29/29 mm.  Shoe weights are essentially identical (within 1%).  

If you’re the kind of runner who likes high-drop running shoes, the FuelCell SC Trail may be a good match for you.  The zero-drop Mont Blanc Carbon is so different, that there’s probably not a lot of overlap between target audiences.  If you prefer low to zero-drop shoes, the Mont Blanc is a better choice.

Saucony Endorphin Edge (RTR review)

Another excellent shoe that felt on the verge of greatness, the Saucony Endorphin Edge has all the necessary ingredients: lightweight, Carbitex carbon plate, roomy fit, bouncy midsole.  This ought to have been a stellar ultra distance race shoe, yet somehow it didn’t quite come together for me.  Even though I enjoyed the Endorphin Edge, in races, I found myself picking the more sure-footed Hoka Tecton X again and again.

Endorphin Edge stack is nominally 36/30 (6 mm drop).  MBC is 29 mm flat.  As with other plated shoes above, weight is pretty much identical.  

I found the Altra MBC last to be a better match to my foot, with better ground feel and foot retention than the Saucony.  On the other hand, if your foot is Saucony shaped, or if you can’t tolerate zero-drop running shoes, the Endorphin Edge is another excellent choice.  The Saucony is also cheaper, at $200 MSRP, and (at the time of writing, at least) can be found on sale.

Speedland GS:TAM (RTR review)

I mention the Speedland here because it also has a (removeable) carbon plate.  But whereas all the plated shoes above are strikingly similar, especially in weight, the GS:TAM is an altogether different beast.  It is built like a tank out of a giant slab of PEBA foam, and has very unusual dual BOA lacing.  Given that this is already an intrinsically stiff shoe, I preferred the feel without the carbon plate.  The GS:TAM feels like overkill for daily running, and emerges at the front of the pack when serious distance is involved.  This would be my shoe of choice for running 200 miles. Price: $275 + $35 for carbon plate.

Altra Timp 5 (RTR review)

If you are skeptical about the merits of carbon-plated trail shoes, or if the sticker price of the Mont Blanc Carbon is just too rich for you, then Altra’s excellent Timp 5 is a compelling alternative.  With 30 mm of stack underfoot, the Timp 5 has enough cushioning and protection to carry you comfortably over any terrain and and pretty much any distance.  Issues of grip and durability that dogged earlier versions of the Timp seem to have been resolved.

Timp 5 stack is nominally 30 mm flat.  Mont Blanc Carbon is 29 mm flat.  Timp is a little heavier at 297 g (10.5 oz) per shoe compared to 273 g (9.6 oz) per shoe for MBC in US M10. Notably, the Timp 5 is exactly the same weight as the original, non-carbon, Mont Blanc.  Timp 5 sticker price is $155.  

Altra Mont Blanc (RTR review)

Comparison to original Mont Blanc is covered extensively above.  To summarize: the original MB was heavier (297 g vs 273 g), and had various issues with fit (most notably lack of heel retention) and durability.  New Mont Blanc Carbon adds a carbon plate and is slimmed down, shaving weight and resulting in a better, more race-appropriate shoe.  Only downside is the price, which jumps up considerably from $180 to $260.  

The Mont Blanc Carbon is available now at our partners

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Tester Profiles

Dom 51, 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.  In 2022 Dom finished 4th in the Angeles Crest 100 and was 10th in his age group at UTMB.

Samples were provided at no charge for review purposes. RoadTrail Run has affiliate partnerships and may earn commission on products purchased via shopping links in this article. These partnerships do not influence our editorial content. The opinions herein are entirely the authors'.

Comments and Questions Welcome Below! Please let us know mileage, paces, race distances, and current preferred shoes

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Anonymous said...

Hi, great review, as always! I find myself always waiting for your guys reviews before even considering buying a shoe online. How would you compare the MBC to the new catamount 3? And yet another question: Do you have the Lasportiva Prodigio in for testing yet and will we see a review of that one? Thanks!

Anonymous said...

White/Orange seems to become the new ugly norm for racing shoes.

Telemarker said...

@Anonymous, you're right. Catamount 3 is a very comparable shoe that should have been mentioned in this review. I've not personally tested them myself, so all I can do is point you at the RTR review for this shoe (https://www.roadtrailrun.com/2024/02/brooks-catamount-3-multi-tester-review.html) or at Mike Postaski's YouTube video review (https://www.youtube.com/watch?v=GvJDn8_9PMk).

I'm hearing good things about Prodigio. We'll try to get hold of a pair!