Dynafit Mercury Alpine Touring Ski Boot Review

I've written a bit about the Dynafit Mercury in a previous article for TGR. In brief, it's an alpine touring boot made by Dynafit that has tech fittings, is part of their 'Free Touring' line and therefore designed to be both about the up and down, has a retail price of $800 and weighs approximately 1600g. The Mercury is the more affordable derivative of the Dynafit Vulcan boot.

Here are features of the Mercury worth mentioning:

• - Three buckle boot with inner and outer tongue. Outer tongue can be removed to decrease stiffness, but adds range of motion in the touring stride.
• - Ultra-lock walk mode; one buckle closure to go from walk to ski mode.
• - 60 degrees of floating cuff engaged via the Ultra-lock Walk mode.
• - Like the Vulcan, the lower shell is the exotic Grilamid plastic designed to be stiffer yet maintain the same basic feel through temperature variations.
• - The upper cuff is a reinforced thermoplastic polyurethane designed to be stiff yet resist lateral flex. It's not as exoticly sexy as the Vulcan's carbon upper.
• - Soles are not removable.
• - Two lean positions: 15 degree and 18 degree.
• - Anaemic looking power strap. I don't even bother using them touring pow. I resort to them as a crutch and use them with the tongues when skiing inbounds.
• - Stock liner is 340 grams. Intuition Pro-tour liner was 220 grams, both with laces.
• - Tongue is 70 grams.

If you want to read more about the Dynafit Mercury (and Vulcan and One) and microparse every single finicky detail about the boots go here to the TGR Forums.

The Mercury is a three buckle boot. It can be used without (left picture) or with the tongue (right picture). Many are swapping the stock Dynafit liners (right boot) with an Intuition liner (left boot) but the stock liner is quite good so try them before splashing down coin.

In powder, I ski the Mercury without the tongues.

Lee’s personal biases and test conditions:

I weigh 165 lbs and ski mainly in the Coast Mountains of British Columbia in the Whistler area. My skiing is usually in fairly high moisture-content snow. I am not a finesse skier. Accordingly, my preference is for bigger skis and boots. I ski about a 100 days a season, 70% of which days involves some backcountry skiing. As of this review I’ve spent 16 days on the Mercury with 4 inbound days and the rest touring in powder. My personal skis are G3 Zenoxides, BD Zealots and G3 Spitfires. My personal boots are the Scarpa Maestrale RS and the Mercury.

Anaemic power straps are included with the Mercury. Per the accompanying boot manual, the powerstraps go through the webbing on the tongue; you can easily detach the powerstraps from the bootshells to accomplish this. I only use the powerstraps when skiing with tongues and do without when skiing sans tongues. Some have noticed power and feel improvement by substituting Booster Straps for the stock powerstrap. 

Fit and the Intuition Liner

I have a traditional Asian foot. This means that my forefoot is wider then most and I have almost no arch. The Mercury has a flat boot boot board so you can add padding to get the fit you want. It's not the "performance" (ie tight) last of the TLT5 boot but feels more akin to the same fit as the Titan and ZZeus. It's less roomy in the forefoot than the Scarpa Maestrale offerings. My guess is that most people with feet that are somewhat "normal" will fit a Mercury with some tweaking. To add more data I'm on a 27.5 boot (boot sole length is 304mm). I fit a Dynafit TLT5 Performance ZZeus, Titan and Titan UL in 27.5 and a Scarpa Maestrale RS, Maestrale, Mobe, Skookum, Spirit 4 and 3 in 27.

Note that the Dynafit liner provided OE with the Mercury is deliberately tightly lasted so it may feel tight in the store. It's very thermomoldable so it will conform well to your foot. My old Dynafit liners (the Mercury liners are made of the same material as the past 2 years of liners) lasted 50+ days so one shouldn't jump the gun and replace liners immediately. Having said that, I have my own Intuition liners that have pretty much worn in to my feet. So after 3 days on the Dynafit liners I replaced them with Intuitions. I've written lots of articles about Intuition liners, am proud to say that I am a fanboy and think they're pretty much the greatest thing you can do for your feet so won't belabour the point other than to say that if you have questions about them please ask on this TGR forum thread or better still check out their website and read about the liners.

The Mercury's buckles are aesthetic wire closures. Improving from the TLT5P the wire is affixed so they cannot fall off the boot and consequently get lost. The bottom two buckles have micro-adjustments (the top buckle has none). The top two buckles can also be adjusted by moving them around using a Torx driver.

The buckles are designed so they don't catch on the snow or get knocked around when bootpacking. I haven't walked around on rock (just snow) at all so I'll have to report back on how the sole wears over time. The sole rubber seems soft so my guess is that sled decks won't treat them too kindly.

Uphill:

The Dynafit Mercury is a wonderful touring boot. Not to diminish its downhill performance, but its fantastic touring stride is its predominant defining characteristic.

At a weight of approximately 1450 grams (I tour without the tongue and on Intuition liners) the Mercury is relatively light weight for the beefy boot category. The free-floating cuff and relatively light weight is really all you need to know about why this is the case. In my opinion, the full benefit of the touring range of movement is best experienced with the tongue removed. However, you still enjoy a relatively resistance-free walk mode even when using tongues inserted.

The buckles have a clean arrangement, so when opened, they stay out of the way and aren't susceptible to being broken off. This is a nice attribute to have for bootpacking and especially nice for transitions as you simply flip open or closed the buckles for uphills or downhills. Having said that the Mercury does have some hitches during transitions. In particular, the square knob on the inner soft tongue of the boot which is meant to receive the harder outer tongue is high enough that re-inserting the tongue for downhills in deep pow is an exercise in frustration. Either cut off or dremel that square knob down or resign yourself to skiing with or without tongues during your day's tour.

Additionally, the black plastic closures of the upper buckle can sometimes catch on themselves while attempting to close the upper buckles. If you feel something catch, don't try to force that upper buckle closed; simply fold one plastic piece under the other and try again.

Protour Intuition liners are fairly soft and feel great when paired with the Mercury in pow.

In more firm snow, the relatively stiffer Intuition Dreamliner or Luxury Liner works beautifully with the Mercury. If one is not blessed with soft snow for touring, the stiffest liner Intuition offers is the Powerwrap. It probably won't help with the touring stride range of motion, but it'll add some beef to the boot.

Downhill

The Dynafit Mercury is a stiff boot. If you want to know how it compares to other boots please ask in the article comments. Suffice it to say that it belies the stereotype of 3 buckle boots not being stiff by being indistinguishable in stiffness from the previous stiffest Dynafit offering, the Titan and Titan UL. The best downhill performance is, of course, with tongue installed. Without the tongues Mercury lost nothing in lateral stiffness but lost its performance in fore-aft stiffness.

More importantly the quality of stiffness of the Dynafit Mercury was very satisfactory. Unlike many other alpine touring boots which have a harsh feeling, and lack small bump absorption I found that the Mercury skied well; behaving predictably even in cut up inbounds conditions. Because the Mercury has so much lateral stiffness the boot felt most at home when laying skis (and boot) on its side and angulating, whether in hard or soft snow. Essentially the Mercury is a boot that enjoys lots of skier input. Drive the boot hard and it seems to perform best.

About The Author

Follow

stash member Lee Lau

Professional Recreationalist. I ski mainly in the Coast Mountains of British Columbia in the Whistler/Pemberton area. I often travel to the Selkirks, the Monashees and to other touring destinations. http://instagram.com/sharon_and_lee