Dynafit Zzero “Green Machine” Test — And Tundra Gets Workout

Post by WildSnow.com blogger | October 5, 2007      
Randonnee boot sole dimensions for backcountry skiing.
Yours, truly on the Green Machines yesterday.

We pulled off a mission up to Colorado’s Montezuma Basin yesterday. Figured we’d find some snow to ski on the permanent snowfield for testing the Dynfafit Zzero backcountry skiing boots. More, we figured the 4×4 access trail would be a good test of just how much our media loaner Toyota Tundra is a street truck. Mission team: photographer AJ Smollen, Louie, Lou.

I wasn’t exactly flying down Montezuma auditioning for a TGR movie yesterday. The snow was difficult and being in a pair of unfamiliar boots with un-molded liners made it tougher. But note I was actually able to put the Zzeros on and go skiing without custom fitting them. I’m not a big fan of evaluating boots by their out-of-box feel (main problem with magazine boot reviews) as I believe all boots should be custom fitted, but it’s worth mentioning my “out of box” experience as it indicates these shoes have a surprisingly neutral last, meaning with competent fitting they’ll work for just about anyone.

As for the experience of skiing the Zzero carbon: First off, I have to tell you the carbon fiber exoskeleton “Power Stringer” delivers, it is definitely not cosmetic. These are honestly the most laterally stiff AT boots I’ve ever been in — at this weight it is amazing I can make that statement. The cuff feels high (even though it’s virtually identical in height to my tried and true pair of Scarpa Matrix). The boot is quite rigid rearward and has plenty of resistance forward for a skier like me (not overly agro). What I found interesting is that a boot this stiff is going to take some getting used to, they’re that different. But it’s a familiarization process I’m looking forward to.

Other things noted: Zzero includes a touring catch on the upper cuff buckles that allows a loose but still buckled position (identical to Garmont). Power strap, for me, is about as necessary as a propeller on a fighter jet, but it’s there if you need it. Lead-in notches on front Dynafit binding sockets do cut fiddle time by a small amount. Buckles are easy to operate compared to others in recent memory, and the spring loaded action keeps them from flopping around and getting caught on stuff if they’re left unhooked. Jury out on liner with conventional tongue, as a wrap-around thermo-molded liners are just so comfy and reliable as to how they interact with our shins. Bright green color burned out 16 pixels in AJ’s camera sensor, but that sort of thing comes with the territory when you’re a photog. Well developed heel pocket in shell should make heel retention better for folks for whom that’s an issue. Shell volume is definitely less than Scarpa, fairly similar to Garmont. Shell last has a lower arch and thus flatter footboard.

In all, Dynafit has come up with something that’s definitely not your run of the mill AT boot and might even be a trend setter. I’ll now spend some time fitting the boots, customize the overall feel a bit, and report back soon.

Toyota Tundra in the Colorado Mountains
Our loaner Tundra got us up the Montezuma 4×4 trail. The truck was at its limit here so it was a good test. As it’s set up, the 2008 Tundra we’re borrowing from Toyota is primarily a luxury street pickup, so we were getting a bit out there taking it up in the mountains. But what’s a gear test if you don’t wring out the goods? I was anxious to try the 6-speed automatic transmission off road, using the “sequential shift” which acts somewhat like a manual. This did not disappoint. Once you drop into 4-low it pretty much acts like a manual, providing an obvious lockup of the torque converter in first gear so you can crawl downhill with plenty of engine braking. And having six gears to row through with a flick of the wrist? Awesome.

As for the suspension offroad, well, it’s a street setup for cornering at 85 mph so what do you expect? Combined with a frame as stiff as the Zzero carbon stringer and a front swaybar as thick as my forearm, we were lifting tires on 12 inch obstacles and getting a bit tired of the challenge by the end of the day (don’t tell my 4×4 buddies I needed a spotter on a 12 inch ledge). But the suspension did work, and could probably be softened up enough for average trailhead-approach use by swapping in a set of adjustable shocks and using a swaybar disconnect. Overall comfort level of the drive on dirt was slightly more harsh than I expected but still comfortable — for proof just ask AJ, he was kicked back in the rear seat watching a video while we descended the jeep trail. We definitely got a laugh out of that.

Of greater concern is the truck’s 9 inch (optimistically put) ground clearance under the front belly pan. Combined with independent front suspension (which effectively drops the belly in rough terrain rather than raising it as a solid axle does), that type of minimal air under your expensive mechanicals makes for nerve wracking driving once you’re in even moderate rough stuff — and for folks in the trades could be a concern while maneuvering in jobsite driveways and such. The stock tires are optimistically 31 inches tall, and there is little room in the wheel wells for an upsize. Thus, for use on moderately rough dirt roads a moderate lift to fit taller tires would be mandatory.

Toyota Tundra in the Colorado Mountains
With AJ and Louie handling front seat duty, I kicked back and viewed the new PW07 flick, so what it’s a bunch of crazy telemarkers? As always, PW made me smile.

Toyota Tundra in the Colorado Mountains
Tailgate time in the Rockies. Thanks for the Grana cookies AJ!

Toyota Tundra in the Colorado Mountains
A few of the rocks that showed us the truck’s limit. All it needs is taller tires and a moderate lift and look out!

Montezuma conditions report: Thin snow over glacier ice. Lots of weir holes in the ice, some large enough to ski into and get hurt. Vertical axle shaft from old rope tow is exposed so know where that is so you don’t hit it. We need to go up there with a couple of hacksaws or a cordless grinder and get rid of that hazard. Heavy snow this weekend will probably produce excellent conditions up there starting early next week.

Alpine touring ski boots on sale here.


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28 Responses to “Dynafit Zzero “Green Machine” Test — And Tundra Gets Workout”

  1. Toby October 5th, 2007 12:11 pm

    Hey Lou,

    Great write up as always and this is now officially my favorite web site so thank you. I was not familiar with the area so I Googled it and stumbled upon a write up on lost ski resorts on Colorado Ski History.com. I am sure many have seen this but I thought I would pass it on as it was really cool to read general history of Colorado skiing and quotes from folks who actually skiied the areas.

    Later and go Rockies!!!!!!!


  2. Randonnee October 5th, 2007 12:47 pm

    Thanks again, Lou, for your informative evaluation and information in regard to Dynafit equipment. I see that you are on my new skis and my new boots in the photo. It will be great to get on my new gear that awaits pickup in a week. I am also thinking that the Zzero 4 will be a nice match for my FR 10 skis.

    Unfortunately, I committed my time to something other than mountains and skiing for the next two weeks, since I know that once skiing starts much of my time will be on the new gear : )}

    Toby, that website is cool. Thanks.

  3. Lou October 5th, 2007 3:12 pm

    The only tricky thing with these excellent boots will be tuning the fit where the cuff transitions to the liner. Due to the stiff cuff sidewalls, the transition may be somewhat harsh for some folks depending on the anatomy of their legs and so forth. Normal boot fitting issues…

  4. Sky October 5th, 2007 3:17 pm

    All right, Lou! Way to put ’em through the paces.

    My powder dreams for today fell short when a trip to the veterinarian became more important. Boo hoo.

  5. Justin October 5th, 2007 3:46 pm

    A number of people have commented about how much lower the cuff of the Zzeros is than the Scarpa Spirits (maybe as much as 2 cm lower on the inside cuff). Do you think the stiffness of the cuff is enough to compensate for them being lower?

  6. Aaron October 5th, 2007 4:10 pm

    Lou, how was the snow in the basin. Hit any rocks if you stay in the middle of the snowfield? Thinking about going Sat, Sun, or Monday depending on this storm. Just looking for a little more info on what the snow was offering up there.

    Thanks much

  7. Geof October 5th, 2007 10:48 pm


    Man… you can just find it… When it’s 82 deg here, you found a bit of skiable snow… GRRR!! Anyway, great write up as always!! A question, you like one whippet or two? And why???

  8. Lou October 6th, 2007 8:28 am

    Geof, the small pick of the Whippet is somewhat ineffective for self arrest of a fall, so having only one for that is kind of a joke. But mostly I like them for climbing aids, and again, using only one for that doesn’t work as well as two.

  9. Walt October 6th, 2007 2:42 pm

    Went up to montezuma 2 weeks ago and found the permanent (?) snowfield to be pretty scary. There were 4 holes in the lower snowfield. I uncovered one hole with a ski pole and could not tell exactly where the bottom was. I dropped some things in the hole and would guestimate it at being about 20 feet deep. The upper snowfield had 2 large cracks running across the entire snowfield( Bergshrunds?).The last time I saw the upper crack was about 7 years ago. We climbed down in it and guessed on the vertical drop of it to be 35-40 feet. Didn’t climb down in it this time because the recurring nightmares from the last trip down have finally stopped. I am not really afraid of being cryogenically frozen but the trip down could be painful.
    P S What is the best backcountry ski out there now?

  10. Randonnee October 10th, 2007 11:47 am

    This morning I was told by my Dynafit dealer that the new carbon boot in sizes larger than size 28.5 have not yet been shipped to North America. Also, that it will be a month until delivery of my Zzero 4 MF and Zzero 3 TF.

    If that is the case, I will be skiing on old stuff (Aero and TLT 4) for a while this season. Like many, I am eagerly anticipating…

  11. Mark Dumont October 13th, 2007 1:32 pm

    Lou – can you elaborate on your take on the liners? “Jury out on liner with conventional tongue, as a wrap-around thermo-molded liners are just so comfy and reliable as to how they interact with our shins.” You mean the tongue is not thermo-moldable?

  12. Justin October 14th, 2007 6:48 pm

    Mark – not to speak for Lou, but what he’s referring to is that the Dynafits liners are totally heat moldable, but have a tongue design similar to alpine boot liners. Many thermo liners have a wrap design without a tongue, such as the Scarpa and Intuition liners.

  13. Mark Dumont October 14th, 2007 8:48 pm

    Thanks Justin. Only have a pair of Garmonts that have a conventional tongue with the thermo-liners; I was actually not aware of the wrap around style to be honest. I have the UPS guy making a border run to the north for me with a pair of 4 C-TF’s, so I guess I’ll be used to the tongue style liner.

  14. Lou October 15th, 2007 7:32 am

    Justin, thanks for helping, my keyboard seems to be wearing out (grin).

  15. Mark Dumont October 15th, 2007 12:34 pm

    Lou – any thoughts on how an Intuition liner might work in these machines? Just wondering if it might be an option for me if I need to upsize if the 27’s I ordered feel too tight even after a pack out (not sure what the boot shell range is when ordering 27’s – will have to see, what did your 28’s cover?). I should be good, but who really knows until I get my feet in ’em.

  16. Lou October 15th, 2007 2:52 pm

    I’m sure an Intuition liner would work, these boots have a pretty normal shape and last.

    I’ll have more about Zzero sizing in a few days, am dealing with that issue as we speak.

  17. colin October 22nd, 2007 3:35 pm

    any news on the Technica AT boot? what’s the flex?

  18. Lou October 22nd, 2007 4:31 pm

    Colin, I’ve seen some info about those but none on hand yet for real-world beta. Soon I hope.

  19. Mark Dumont October 25th, 2007 9:58 pm

    Lou – just got my green rides in from UPS. As you said, not a bad fit out of the box; but I will need an overall tweak, especially my larger right foot. No instructions came in the box on heating the thermoliners. Any suggestions? Did I miss something elsewhere you may have posted? Do I wait for the article you plan to graciously post for us all?

  20. Lou October 26th, 2007 9:04 am

    Mark, I’ve got another pair coming in a different shell size. Will blog about that and doing the liners just as soon as they’re here. Dynafit, just like Scarpa, is now recommending the liners be heated while inside the boots, using a blower system. Unfortunately that’s tough for the DIY routine and somewhat of a marketing mistake in my opinion since the average shop doesn’t do any better job with this stuff than a competent home craftsman, and shops are frequently busy, charge too much, or are not extant in a person’s area. In my experience these sorts of liners can still be baked in an oven, with care not to go too high in temperature.

  21. Marc February 22nd, 2008 11:12 pm


    Any comments on the Dynafit Zzero 4C now that you’ve had a good portion of the season on them? How are you liking the performance, fit and durability? One question I have is how are the carbon stringers holding up to ski edge contact? My boots tend to get a fair amount of wear around the inside of the ankle area and I’m wondering how yours are doing. Let us know how the long term “testing” is going.

    Cheers, Marc.

  22. Lou February 23rd, 2008 7:01 am

    Marc, I’ll do a long-term test eval next week. They’re holding up fine, with expected wear. I’ve got quite a few days on them.

  23. Andy May 10th, 2008 7:37 am


    A friend of mine has had a pair of the new Dynafit Zzero carbon AT boots all winter and loves them. However next to the sockets in front on both boots the plastic has cracked backwards down to the sole. Have you seen this before? Dynafit hadn’t. They did see a very large number of days on them also.

  24. Chad October 2nd, 2008 10:32 am


    I have purchased the 07/08 Zzero C4″Green Machine”. I have been skiing only Garmont boots-Mega Ride for the last 5yrs. I wanted to change to the Dynafit based on some great feedback I have heard from friends, and reviews. My question is regarding the low profile spoiler on the back of the boot. What have you found in some of your research regarding some of the performance differences between the Dynafit, and Garmont regarding the design differences in this area?

    I would be using this boot for strictly touring in the BC, and ski mountaineering in our beloved Elk Mountains.

    Thanks for your time, and info.


  25. Lou October 2nd, 2008 11:47 am

    Chad, just compare the height of your rear spoiler on former boots with Zzero, and compare height of liner. If they’re pretty much the same you won’t notice any difference. If not, ski ’em and add something back there if you feel the need. It’s not a big issue.

  26. Mike November 18th, 2008 2:26 pm

    Hi Lou,
    I have a question on the Zzero4 C-MF. Do you know if the MF versoin of the boot will fit different than the TF version? I have tried on a (2008/2009) TF mondo size 26 and it felt great. However, I found a great deal on a (2007/2008) MF version in mondo size 26.5 – so I went for it. To my knowledge, the shell size should be identical (b/w 26 and 26.5). Ordered online (with 100% satisfaction guaruntee) so I wasn’t able to try it on.

    But just looking at pictures, the MF liner looks much thicker than the TF liner (at least at the visible upper cuff area.

    Also, are the MF liners heat moldable?

    If the MF liner doesn’t work – I have a g-fit liner (for an old G-ride) in good shape that I’m hoping will help.

    I just haven’t been able to find much information on the comparisons of these two liners – besides the weight difference. Also, the MF seems like it may add a smidge of stiffness – which is welcome.


  27. Lou November 18th, 2008 3:31 pm

    The Dynafit MF (Multiform) will add a smidge of stiffness and no it’s not thermo form. TF stands for thermo form. Multiform is a good last that fits lots of different feet, and can be moderately customized by a boot fitter. Lou

  28. Lynne Wolfe March 27th, 2010 11:07 pm

    Hey Lou et al-

    I have a pair of the Zzero PB boots, actually pair number 2 as the first pair also got a crack just behind one of the front pin holes. This pair now has the same problem (Dynafit warrantied them once already). Anyone else coming up with this problem? The first pair had 2 seasons of probably 100 days apiece, but this pair had maybe 60 days, mostly backcountry.


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