Review - Dynafit Mercury boots

Recently I took the plunge and splashed out on some new touring boots - the intention being to get a pair in the 1.5 - 1.7 Kg bracket which increasingly offers boots which will drive a big ski really well while not being too heavy for the uphill/climbing.

Last winter I was mostly skiing Dynafit Titans (big and beefy, but heavy), Head alpine boots (Raptor 120), and also spent some time in Dynafit's TLT5 Performance boot (super light, but a bit narrow for my foot even with some shell-stretching, and in my opinion missing a third buckle for good heel hold - full review here).
Seb at Sole Boot Lab in Chamonix took care of boot selection and fitting and I have now skied a pair of Dynafit Mercurys for a week so can offer some first opinions...

Weight. No matter what the manufacturer's blurb tells you, there is no substitute for getting the scales out - the results are as follows (for one size 28.0 boot):

TLT5 - stock liner + superfeet 'green' footbed: 1.253 Kg

Titan - Palau liner + Superfeet cork footbed: 2.087 Kg

Mercury - stock liner + Sidas footbed: 1.734 Kg

- just slipping outside the 1.7 Kg upper limit I had set, but still feel relatively light on the foot - only a big uphill day will tell though!


The Mercury is a 3 buckle boot - though the 40mm booster strap more than happily doubles for a 4th buckle on the cuff. The buckles remain low profile when closed - should be fine for climbing/boot-packing. In the open position the cuff buckle has a hinge point to enable it to sit closer to the boot shell - one of the downsides of the TLT5 was the buckle which stuck out a long way in 'open' position - check out the photo below to see the difference between the two:

Fit-wise I have a narrow ankle, high arch, and wide forefoot. The Mercury's fit out of the box is not bad for me, though I will need to widen the toe box a little for maximum comfort. For comparison they feel narrower than a Titan, but substantially wider than the TLT5

Conditions in the French Alps are a little scratchy at the moment, and most of my work last week was on piste (for once) so I haven't tried these out with any fat skis yet - last week I was skiing some Fischer Watea 88s and the boots were quite happy to really crank it out on piste. Good support, great heel hold, and a progressive flex pattern. The cuff height is similar to a Titan (see photo below - from left - TLT5, Mercury, Titan):

The boot sole length of 314 mm (for a 28.0) is only 8 mm down on the Titan (as opposed to 307 mm for the TLT5 !), so if you are swapping down from a bigger boot this should fall within the adjustment range of most tech bindings (eg Dynafit Vertical/Radical or Plum)

Downsides? During thermo-forming one of the liners developed a crease just above the heel on the instep - manageable this week as my heel has been locked down in ski mode, but could be an issue on the uphill and I will be heading back to the shop for a re-form or new inner. Apparently this has been a regular problem with the stock Dynafit liners!
Just like the TLTs, the lock mechanism for ski mode is integrated into the cuff buckle so a cover of some sort will have to be DIY-ed to enable light closure of the cuff without locking the boot for more technical climbing

So far I am really happy with these boots and can't wait to get out on some bigger skis and see how they perform...

Dynafit TLT5 review

Its getting to that time of year when people start thinking about new kit for the winter. I have been promising a review of the TLT5 boot from Dynafit for some time and here it is (finally).

*Note* This review is simply my first thoughts & impressions based on approximately 20 days skiing/touring in the boots last winter. The boots were skied with Dynafit bindings on a pair of Dynastar Mythic Light skis (184). For those who don't know my skiing style then a quick look through the archives of this blog should give you an idea...

First off - these boots are light, light, light!  When I first put one on it felt the same as having a running shoe on my foot - though in reality the boots do weight in round about the 1Kg mark per foot. For anyone coming from an alpine boot or beefy touring boot background this is a major change - even compared to the Scarpa Maestrales which I dallied with for a few outings (see here) these boots are in a different league.

Dynafit TLT5 P

Comfort - the TLT5s are built on a narrower last than the Titan (my regular winter boot) and for my forefoot they needed a bit of gentle widening (thanks to Jules & Damien at the Boot Room) - this can be done but care needs to be taken as you can stretch too far and create a gap between the forefoot bellows and the rest of the clog.
The inners are very thin compared to my regular thermo liners (Palau) but were surprisingly warm considering. After the stretching above the boots have been very comfortable

The TLT5s only have 2 buckles - one over the forefoot and one around the cuff (+ a velcro strap at the top) - the cuff buckle also doubles as the ski-mode locking mechanism; the tongue is also removable for those who want a bit more flex or movement (not something I bothered with on the way up or down).
It is worth noting that the TLT5s are designed to work with 'low-tech' bindings ie Dynafit or Plum etc. I have heard of people using them with Fritschi etc, but the reduced rand on the toe of the boot is not designed to work with a normal step-in binding - on your own head be it...

The second thing you notice with these boots is the range of movement in walk mode (or walk/run mode as Dynafit call it!) - pop the cuff buckle open and you have masses of ankle movement - an amazing experience for anyone used to skinning with a heavy 'freeride' boot. Combined with the light weight these boots almost make going uphill a pleisure (almost)!

How do they ski?
Pretty damn well considering there is so little to them - the 2 buckles give reasonable foot hold in the boot and the carbon shell is super-responsive giving good support and lateral control. In most snow conditions skied these boots were just fine though in heavier snow I personally would have liked a 3rd buckle over the instep to help hold the heel in the 'pocket' - if you are being thrown about fore & aft it is noticeable that the foot isn't always pinned down into the back of the boot...
The forefoot flex (due to the bellows) is also noticeable on firmer snow - giving a strange feeling sometimes - almost a bounce, or sag as you load up the ski - for this winter I will be riveting this out (see Wildsnow for details) as it is superfluous to me (I don't intend to run in these boots...).

Other points of note are the fact that when the boot is in walk mode the cuff is wide open which isn't ideal if you are booting up a steep slope or climbing. The buckle is also quite bulky in walk mode:

This is definitely a downside for mixed climbing (or even bootpacking a firm set of boot holes) but can be easily solved by adding a small flap of plastic to cover the locking hole on the back of the shell - this means you can clip the boot almost-shut without locking it, maintaining ankle movement but with a low profile clip and without the risk of falling out of your boots!


In summary:

Pluses:  Super light weight, great walk/skin mode, responsive to ski

Minuses: Bulky walk mode, metatarsal flex, lack of an instep buckle

Overall I have been very happy with these boots and can't wait to give them more of a work out this winter.

It is worth noting that in Dynafits 2013 range the Vulcan and several other models potentially fill the gap between these and the Titan (even the Ultralight) and fix some of the minuses above (3rd strap, no metaT flex) and could well be THE boot (though at ~500g per foot more).

Worried about if you can rip on these boots? Check out this video from Gilles Sierro...