Stefano Maruelli went public with his Natural Walking Plate (NWP) ski binding add-on back in 2011. He’s been working on development and marketing ever since. Though the product isn’t mainstreamed by any means, I’ve always found NWP to be an interesting solution to a host of issues rising from the unnatural gait of walking with climbing skins on skis.
Maruelli makes strong claims for added efficiency — in the double digits. That might be optimistic but he makes a good argument, claiming that much of the energy savings is due to the ski never being lifted off the snow during the stride. He says that sliding the ski is markedly more efficient than lifting it — something most of us know intuitively since our skin climbing stride is usually that of a quiet gliding gait, rather than the gorilla stomp of a newbie.
Nonetheless, there are times when lifting the ski is at least somewhat is more efficient than sliding it. Also, it would take some fairly complex engineering calculations as well as bunches of real-world testing to ‘prove’ that the NWP is more efficient — whatever the claims are. It’ll be interesting to watch that, while meanwhile this is indeed something to look at actually owing and using if the repetitive motion of skinning is causing you any back or hip problems.
So, I tested. Did a resort uphill of about 700 meters vert, with quite a bit of different angles and snow conditions. A couple of conclusions:
First, yes the NWP in use looks like something from the Ministry of Silly Walks (google it), especially when Stefano exaggerates the motion to get the user to make a stride that takes advantage of the device. But really, it is just a ‘different’ stride, and if the device did become popular we’d probably get used to seeing it.
Of more importance, what exactly does the NWP potentially do for a backcountry skier? Or is it a solution without a problem? For starters, it was obvious to me right away, as mentioned above, that if you have any back or hip problems from years of skinning you might be able to purchase this simple little jingus and be healed. The motion you use with the NWP is that much more natural, and different.
The big question is does NWP increase efficiency enough to cancel out the weight, as well as giving a little something extra? I didn’t feel enough of a speed boost to give a nod to that. As mentioned above, Stefano does claim this to be so, and says he’s going to have an oxygen uptake study done to prove it. It’ll be terrific to see that, though ultimately he’ll need to step away and let people such as ski racers decide just how much faster this thing (perhaps) makes them.
Durability is also an issue. If NWP is made to be super light so it most definitly will compromise between durability and mass. If you take a forecefull fall with it deployed at full extension the leverage forces will be immense. Something would probably have to give. Basic logic, though we did not test durability.
Meanwhile, just a quick verbal description of how the NWP works. Really quite simple, though about seven years of work have gone into having something that could go retail.
The device is a plate (double rail frame), with a single hinge/linkage in the rear and a multiple extendable linkage in the front. The plate rises with the natural arc of a person’s foot while they’re doing a walking or running stride. Yes, you can do nearly the same motion with a regular AT binding, but when doing so you’d have to be lifting the ski tip up at part of the stride, then the whole ski during another part. All resulting in constant lifting of the ski and sucking of energy. The NWP simply allows that natural motion while nearly leaving the ski alone, sitting on the snow, quietly gliding forward at the appropriate time.
When it comes to the weight issue, Maruelli is adamant in contending that the added efficiency of his system makes a bit of added weight of trivial concern. Nonetheless, our view is that weight still matters since you’ll not always be able to do the perfect stride even if you’re using the NWP, but more, because you may be carrying your skis on your rucksack.
Whatever the case, here are Maruelli’s official weights. He’s pretty careful about this sort of thing, so I trust these:
NWP-TLT 360gr each plate for the Dynaift TLT Speed binding (60gr can be removed from the TLT rear binding using an available screw base).
NWP-LITE 320 gr each plate (for LowTech race or Trab or ATK bindings on request).
NWP-RACE including integrated race bindings: 340gr each.
Again, something to watch, and even consider if you’ve got any physical ailements due to the ten-to-the-fourth-power number of skin strides you’ve done in your life. In my case, I could see at least owning a set of these on one of my pairs of workout uphilling skis. I think mixing it up a bit would really help my back and hips. Besides, perhaps I could get a job with those guys at the Ministry of Silly Walks.