Altra Mont Blanc Carbon Review
This week we’re moving quickly over trails with our Altra Mont Blanc Carbon review. The Altra Mont Blanc Carbon is a neutral trail shoe designed for quick running on hard packed tracks and trails.
Carbon plated shoes for trail running are always a bit controversial. As they need a flat, firm surface to work most effectively.
There are three aspects to carbon plated running shoes that help the runner run quicker. The shoes have a low heel to forefoot drop and the midsole is curved. This encourages the runner to land on their midfoot which reduces the braking forces and the curve or rocker in the midsole keeps the foot moving. The second go faster element to these type of shoes is the midsole foam. This has a very high rebound which helps maintain a quick cadence and a strong push off. The third element is the carbon plate. This firstly stiffens up the shoe so that it maintains the curve and therefore the rocker action for a long period of time. Shoes without a carbon plate stop being as effective when you have been out a while as the rebound quality of the foam reduces and the shoes get more flexible. The second thing the carbon plate does is mimic the action of the planta fascia on the bottom of your foot. When your foot lands on the shoes the carbon plate is flexed or loaded. It rebounds back at push off which gives the runner a bit more spring and increases the stride length (distance covered in the air). Hence the runner covers more ground for the same level of effort. The problem with using this type of carbon shoe on a trail is that you don’t have a flat firm surface or every foot strike. So, a stiff carbon plate won’t get loaded properly with every stride. The stiffness of the carbon plate also prevents the shoes from riding over uneven broken ground. Even a hard packed forest trail has lumps and bumps in it that could cause a stiff shoe to tip over twisting an ankle or a knee.
Altra’s Mont Blanc Carbon has been designed to be a versatile trail shoe that feels good on hard packed trails but is also versatile enough to cope with more broken ground as trail races often have a mix of underfoot conditions.
The midsole has an Altra Ego Max cage that runs around the outside of the midsole but is hollowed out in the middle like a bath. Inside the hollowed-out space is a carbon plate then on top of the carbon plate is Altra Ego Max Pro which is a Nitrogen infused foam that is very soft and has a high degree of rebound and durability. Midsole foams are rubber mixtures which have air blown through them to create lots of little bubbles. A nitrogen infused foam is sealed so the air can’t escape and water or grit can’t get in. This means that the foam doesn’t degrade as fast and as the air can’t escape it makes the foam a bit like a balloon. Which gives the midsole a higher level of rebound than you get from a none Nitrogen infused midsole.
The carbon plate in the Mont Blanc Carbon has been developed by Carbitex and is amazingly flexible in all directions. This is perfect for a trail shoe as it means that even when running over a boulder field or on a track covered in roots the shoe is capable of bending and flexing with the ground. This allows the runner to keep moving forward rather than being thrown from side to side by a stiff shoe. The positioning of the carbon plate means that it also acts as a rockplate/stoneguard. Preventing thorns of sharp rocks from piecing the midsole and damaging your feet or bruising your feet.
Altra is all about developing running shoes that work with the body’s natural movement. There shoes help you run better rather than some other running shoes that try to replace your feet. For this reason they all have a rounded toe box designed to give your feet the room to spread on impact. This means that you get cushioning, stability and propulsion from your feet. The impact forces of running are spread-out each joint taking a little bit of the force. Shoes that are tight fitting with pointed toe boxes prevent foot function which means that you lose the shock absorption of your feet and ankles which overloads your knees and hips. This can lead to wear and tear on those joints over time.
The flat or zero drop design encourages a more midfoot landing. This loads the foot more naturally encouraging it to use the space in the toe box and spread out. Although the Altra Ego Pro is soft the carbon plate that is below it gives it a firm surfaces to rebound from and so you don’t feel like you are sinking into the midsole in anyway. This makes the Mont Blanc Carbon feel nimble and responsive while running uphill, downhill or on the flat. Your foot can also feel that you have touched the ground which means that it will spread and function inside the shoes. If the midsole is too soft then your foot doesn’t get the feedback it needs to be able to function in the shoes.
The volume and width of Altra shoes varies. They make three different lasts. The slim fit has the least volume and the original fit the most width and volume. The Mont Blanc Carbon has been made on Altra’s standard width which sits between the slim and original fit. If you are used to wearing other running brands with a more pointed toe box then these will feel a roomy shoe. If you are an Altra fan who prefers the original fit then these would still be worth a try as it is one of the more roomy standard fitting shoes. In my experience there is more volume and width in the toe box of the Mont Blanc Carbon than there is in the toe box of the Timp 5. This is a good thing as the Mont Blanc Carbon is designed to be used as a racing shoe for Ultra distance trail races. So, you want the space so your feet still have the space to function even when they have expanded a bit.
Although designed for Ultra Trail the Mont Blanc Carbon doesn’t feel bulky or overly cushioned. It feels, comfortable, light and nimble. I would quite happily use them for much shorter races. Although the stack height is 29mm they feel like a much lower stack and nimbler shoe than you would expect.
The heel cup has no plastic in it so that it can take the shape of your heel. It is stiffer with a bit more padding around the heel cup and cuff than the regular Mont Blanc. This gives a snug and comfortable fit. Very different to the fit of the heel cup of the Mont Blanc which although it didn’t give me any issues always felt like it didn’t have hold of my heel. The tongue comes nicely above the laces and wraps around the lower part of the ankle. The tongue is lightly padded but this is adequate to protect the foot from any tension from the laces. The tongue is gusseted which together with the way it wraps around the lower ankle helps to keep debri from getting into the shoes. If debri is a problem or you want the shoes to be a bit warmer than you could attach a gaiter to the shoes. The Mont Balanc Carbon has a Velcro gaiter attachment on the outside of the heel cup and a loop as the bottom of the laces to attach a gaiter. There is an extra lace hole so if you wish to gain a snugger fit around the ankle then you can put the laces through this additional hole or butterfly lace the shoes.
The lace holes are attached to tapes that are secured at the base of the shoe. This helps pull the upper in around the foot. This does secure the foot inside the shoe but isn’t the only reason that you don’t experience much movement in the shoe even when running over rough ground or on a camber. The combination of your foot being able to function inside the shoes and the flexibility of the midsole in all direction means that the shoe can bend to the curvature of the ground so your foot isn’t under pressure to move inside the shoes.
The outsole is the same as is used on the regular Mont Blanc and is made from Vibram’s MegaGrip Lite Base. This outsole construction uses a thinner base material which helps make the shoes more flexible, gives getter ground feel which helps to give the shoes a nimble feel and stimulates the foot to function inside the shoes. The lugs are 4mm in length and the rubber is designed to grip well to wet and dry surfaces as well as be durable enough for harder packed trails. In my experience the grip is very good on hard packed ground. It is versatile enough to cope with some greasy single track but the lugs aren’t deep enough to offer much in the way of grip on wet muddy ground. This is understandable as carbon plated shoes need a firm surface to work effectively so the outsole has been designed for harder packed trails. However, in my experience the Mont Blanc Carbon is still versatile enough to cope with patches of muddy ground. This is mainly due to the nimble feel of the shoes and the running style that zero drop shoes encourage. Essentially you are light on your feet, lifting of the floor so you can dance over muddy section without too much issue.
The Men’s UK 9.5 weighs 309 grams and the Women’s UK 6.5 weighs 249 grams. Like all Altra shoes they feel much lighter on your feet as they work with the natural function of the body.
We where lucky enough to get a pair of the Altra Mont Blanc Carbon a month before the UK launch date. So, we have had the chance to get plenty of running done in the shoes as various paces and over various distances on a variety of trail type terrain. When we first ran in them it was noticeable that they didn’t feel like they gave a lot of propulsion. Carbon plated shoes tend to have a ‘pop’ or spring to them. They make you feel like you’re bouncing down the road with no feeling for the ground. For me this takes away the feeling of running and I don’t feel smooth or in control. The Altra Mont Blanc Carbon is completely different. It feels like a nice comfortable, nimble trail shoe. It doesn’t try to control your cadence or stride pattern. It is so flexible that you doubt that there is a carbon plate in the shoes. However, despite not having the ‘pop’ we are used to with carbon plated shoes they do seem to help you run quicker when you’re on the right surface.
On a long run of two hours plus I noticed that because the shoes have maintained their structure, they do keep my legs ticking over when they are tied. Making me quicker in the last 30 minutes or so of the run than I would usually be for the same effort. A surprise as I’m just trotting a long on these runs not looking to run quickly at all.
My Threshold loops are 7-8 minutes long depending on how wet it is and my current fitness level and consist of 3.5 minutes of undulating hard packed track followed by a gradual climb up a root and rock covered single track with puddles and mud in-between the obstacles before a steep muddy descent to the finish. What I noticed was that despite me slowing down as the wet, muddy conditions took their toll the time it took me to do the hard packed track section remained the same with the same heart rate on each loop. Which would suggest that the shoes are helping on the hard packed track section. On the remaining rougher section of the loop, I didn’t feel that the shoes hindered me. I had no concerns that I would twist an ankle or knee while skipping from root to root as the shoes bent and flexed with the ground.
On steep descents where I was landing heel first, I found that there was ample cushioning but the heel felt stable and didn’t collapse. On steep climbs I had a real positive push off feeling which must come from the carbon plate as you don’t get the same feeling in other Altra trail shoes.
Interestingly after a long run or long threshold session I didn’t get the tight tired quads that I would usually experience. This could be due to the cushioning and carbon plate reducing the impact or it could be because of the more natural gait that Altra shoes promote which makes you lighter on your feet and helps to reduce overstriding.
I am always weary of running too much in running shoes that do some of the work that your body should be doing. This is because I find that it gradually weakens the body, and this leads to niggles. The Altra Mont Blanc Carbon put me in a quandary because they feel so nice to run in you want to run in them all the time. You can feel your feet being stimulated and spreading on impact. Which would suggest that my feet are still functioning inside the shoes. Despite this I have still exercised caution and used them only once a week.
In summary the Altra Mont Blanc Carbon is a carbon plated trail shoe designed to help you run quicker and maintain pace on hard packed trails. In my experience it does both of these tasks with the added benefit of encouraging a natural movement pattern and stimulating foot function.
Other Considerations
Brooks Catamount 3: These don’t feel as softly cushioned, and you are more aware of the plate in the forefoot. https://www.northernrunner.com/blog/brooks-catamount-3-review/
Hoka Tecton X 2: These have a split carbon plate. The two prongs move independently to help the plate negotiate rough ground. They have a bouncier ride which takes away some of the feel for the ground and makes you less nimble in the shoes. https://www.northernrunner.com/blog/hoka-tecton-x-2-review/
NNormal Kjerag: Although these don’t have a carbon plate, they do have a firm-ish, nitrogen infused midsole that helps with propulsion. There is a good level of ground feel despite the firm midsole. They aren’t as flexible as the Mont Blanc Carbon. The lugs are a bit shorter and flatter so don’t grip quite as well on greasy, muddy single track but like all these shoes they are designed for harder packed trails. https://www.northernrunner.com/blog/nnormal-kjerag-review/
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