Through the good graces of boot distributors and makers, we can compare fit between a Dynafit Zzero “Green Machine” (size 28 and 27), as well as Scarpa Laser and Matrix in 28. We’ve got experience with Garmont Megaride 28 as well, so I’ll also comment on those. (Note we’ve got some of this year’s Scarpas coming, so we’ll do a more specific report on Scarpa fit when they’re here.)
First off, let it be known that trying to actually measure boot volume is a tedious and time consuming affair. For example, nearly every surface on a boot curves, plastic varies in thickness, and even the rocker of the footboard influences how your foot responds to actual boot volume. Thus, I measured inside length (even that is a bit subjective due to curving surfaces), but will report more on an overall impression of volume and fit rather than specific measurements.
Also know that Dynafit is not sold in half sizes, while Scarpa is. This is not as big a deal as it sounds, as the shell sizes of both brands are designed around full sizes, and the 1/2 size increments are created by the liner. For half sizes, Scarpa simply provides liners that are pre-molded to the 1/2 size. This is no doubt more convenient for the customer buying boots in a shop and trying to fit liners and boots. Conversely, any good boot fitter knows that you should fit a boot by the shell size and after that simply mold a liner to tune the fit, so having 1/2 sizes is not as big a deal as it sounds, and can even confuse the issue.
So, since I’m working on getting a good fit from the Zzero Green Machine, I’m playing around with two shell sizes: 27 and 28.
Interestingly, Green Machine 28 has a sole length of 316 mm, while a 28 in Scrapa Laser and Matrix is 314 mm (and the Garmont Megaride 28 has a whooping sole length of 320mm). More, Green Machine has a noticeably deeper heel cup. Result is that a 28 in the Dynafit, in comparison, is slightly larger for its labeled size and I end up between sizes. (Dilemma for me, but equally of benefit to a person who’s been between sizes in the past and can now find a better fit.) If I go to the 27 with a sole length of 306 mm, I can stack two fingers behind my heel (foot in shell with no liner), but it seems slightly short based on much previous experience with the shell fit I need.
On the other hand, with no liner in the Dynafit 28 I can nearly stack three fingers and it feels large when fitted with the unmolded liner. I want performance out of these boots. The shorter size 27 is definitely going to ski downhill better for me, and it’s a better fit for all the skis I’ve previously mounted for my Scarpas. More, the longer your boot is the less efficient for uphill skiing and dirt hiking. So I’ll be working with the Dynafit 27. I’ll create more length during molding by making sure I force my heel back in the pocket, and using spacers on my toes. Only risk with that is the toe area will be cold for my sensitive toes because of compressed foam, so if possible I’ll mold in a chemical boot warmer pocket during the process. I may punch out the shell a small amount as well — a procedure that’s common in the ski world and that any competent boot fitter should be familiar with.
Now for specific comparo. Overall, it’s obvious that the Garmont has the least volume, with Dynafit next in line and Scarpa having the most. This is due mostly to the height of the toe box and configuration of the heel cup. But don’t mistake volume for width. Dimension at the ball of the foot is similar (27 Dynafit and 28 Scarpa) in all these boots with an edge to Scarpa for slightly wider width. Also, the boots all have slightly different mold shapes that result in a different feel when testing foot in shell with no liner. This is the reason some folks will call a boot “narrow” and some will call the same boot “average” — testimony why if you want the ultimate fit it’s best to get your boots at a shop where you can try on sizes/models/brands. As for the Green Machine 28, it does have slightly more room side-to-side than the 28 in Scarpa and Garmont — which goes along with my initial impression of it being a somewhat larger boot for its stamped size.
Aside from how you define a given size, my biggest impression of these boots is that the Zzero shell has a deeper heel cup. Like anything else in boot shape this will help some folks but be less useful for others. For example, if you find you always need better heel retention this could help you a ton (as it does me), but if you tend to get pressure points on your heels you might need some tricks when you mold the liner to compensate for that. Again, normal stuff that any competent shop or boot fitter can deal with in their sleep.
FYI, I did measure the inside length of Zzero and Scarpas. 28 Laser, Matrix and Zzero all have a similar measured inside length, but the deeper heel cup of the Dynafit adds more real-world length. The 27 Zzero inside length is 1 centimeter shorter (as far as I can tell in dealing with the curved surfaces and such), which matches the difference in sole length between the 27 and 28.
ONE OTHER THING: Remember you can still register to win a pair of free Dynafit Zzero boots. Check it out here! Remember, as far as any of us can tell this early in the game these boots are indeed incredibly light for their performance — possibly the best mix of those factors ever produced. Some folks think they look pretty cool as well. After all, earth tones are so 1990s?
I’ll be happy to answer specific questions about the boots in this comparo (leave questions as comments). Also, I know many blog readers have vast experience with the fit of AT boot brands, so please leave comments with your take if you feel the call.