I’ve gotten my boot into all but one of the current breed of hard boot bindings available on the market, but there is only one pair I have used religiously for two solid seasons without wondering what life was like with my older binders. That’s the Plum Sok. The Plum Sok’s hallmark is a solid aluminum baseplate, a ton of adjustability and reliability. My pair has survived well over 150 days of touring and show no sign of letting up.
Overview
- Material: 7075 Aluminum
- Boot Size Range: 270 to 330mm
- Country of Origin: France
- Seasons Used: 2.5
What is the Plum Sok?
The Sok is Plum’s first—and currently only—hardboot splitboard binding. The baseplate is CNC-milled from a solid block of 7075 aluminum and closely resembles the one used on Plum’s Eterlou bindings. Every part is replaceable, though some of the smaller bolts could be tricky to source or replace in the field. Don’t count on finding spares at your local hardware store.
The Downhill Interface
I’m not one for following instructions so my first time putting the bindings on my board took a little finagling as it is not entirely intuitive. Had I followed the instructions as they are quite simple. Two opposing half‑moon brackets mount to each board half, curves facing inward. Small curved plates slot into these to act as screw limiters and to mark your stance angle. Plum also includes an insert for the underside of each bracket, though I’ve never found a reason to use it..
On top of the brackets sit two triangular plastic binding receivers, flat sides up and capped with small steel plates that serve as bolt limiters. There’s no positioning guide, so I finger‑tighten two bolts, tighten a third nearly all the way, then attach the binding. I close the binding until there’s just enough pressure to draw the board halves together before cinching the remaining bolts.
Engaging the lever moves an internal plate that pushes against the toe‑side receiver, locking the binding onto the board. A small plastic clip—one of only two bits of plastic on the binding—keeps the lever closed. I doubted its durability at first, but after 2.5 seasons of real abuse, it’s still intact.
Levers and Bails
The toe lever, hinge pieces, and the toe bail connector are all aluminum. The only non‑metal parts are the boot limiter and the small plastic insert between the lever and boot, which is replaceable via three screws. That’s a great touch, since fully metal levers on past bindings chewed up my boot shells over time.
I did manage to snap the toe limiter once when I used my board as a pry bar during a bootpack. Fortunately, only the broad end broke off; I lowered the screw slightly and have since added another 30 days without issue.
As with all hardboot bindings, brush snow off your soles before stepping in. Packed snow can apply unwanted stress to the system and risk damage.
Adjusting for Boot Size
The Plum Sok accomodates boots from 270mm to 330mm. This is a massive range and should suit every boot on the market. Therefore, there is only one size of Sok.
There are pour positions for the toe bail. Interestingly, there is a rather large gap between the foreward most position and the back three.
In order to move the toe bail, one of the lever bolts needs to be removed to gain access to the toe bail retention plates. Then, each retention plate has two bolts. Remove the bolt closest to the front of the bindings and rotate the plate out of the way.
The heel bail has a channel for adjustment. From the top of the binding, loosen the four screws holding the bottom sliders in. You do not need to fully remove these screws. Then, the heel bail can be slid forward are back. The receptacles for the heel bail also have two positions.
Caveats of the Plum Sok:
You Cant with the Plum Sok
With the Plum Sok, you simply can’t. Hardboots aren’t meant to flex inward, so most bindings include about 3° of canting to ease knee strain. The Sok offers none. With my Key Disruptive boots’ strong lateral flex, that’s not a problem. But with my Atomic Backlands, I definitely get a pronounced cowboy stance. Narrowing your stance helps relieve knee pressure if this becomes noticeable.
It’s easy to land bolts on the Plum Sok
Each binding uses eight bolts for the downhill interface, plus 21 bolts for the binding. Initially, that many fasteners gave me pause—but the performance payoff has been worth it. After 2.5 years, only one bolt, on the toe lever, has loosened and one bolt on the bottom is on ajourney of its own. That’s pretty darn good for 2.5 years of heavy use. Still, my spare‑bolt kit has grown rather large.
The Untested:
Heel Riser
The Sok ships with a wide‑based plastic heel riser featuring two broad flip wires. I didn’t use it—I was focused on testing the bindings themselves and already had Rocket Risers mounted. The included riser offers minimal fore‑aft adjustability and is meant to pair directly with the Sok baseplate.
I hope to get a pair of the Plum Heel Risers soon and look forward to having a viable alternative to the Rocket Riser, soon.
Included Tour Bracket
The Plum Sok comes with a touring bracket to attach the Sok to instead of a tech toe. To me, this would negate a lot of the advantage of having hard boots. Extra weight on the feet is far worse than weight in the back pack. I admittedly never used these touring brackets. Why would I when Plum already makes a fantastic tech toe, the Pekye.
You can read my review of the Plum Pekye HERE.
Plum Sok on Snow
My relationship with the Plum Sok started rocky—I stripped a bolt while trying to move the heel bail, thanks to overzealous Loctite. A machinist quoted me a small fortune to drill it out. Thankfully, Plum replaced the baseplate under warranty, and since then, it’s been smooth sailing, crappy conditions notwithstanding. Any quirks I’ve encountered have been pure user error.
I try to make a point of knocking any sticky snow off the bottom of my boots but sometimes the stoke takes hold and I forget. Only once has this resulted in a mid ride binding release. Again, that was my fault for not being diligent with snow removal.
I’ve used the Plum Sok from the top of Hokkaido to heli boarding in Bella Coola. Hot spring days to 40 degree chutes with snow that was as hard as cement. They have performed well for me literally every day I have taken them out.
Wet snow is not a problem for these bindings. When transitioning to downhill mode, I lightly brush off any snow on the downhill interface, line the binding up, and close it. The binding does a fairly good job of self cleaning which helps speed up transitions.
Who is the Plum Sok for?
This is a stiff, performance‑oriented binding built for riders who prioritize precision and reliability.It is not for someone looking to maintain the flex of their board. Really, anyone on a hard boot should not be worried about maintaining natural board feel.
The Plum Sok has been an incredibly reliable and fuss free binding for me over the last 2.5 seasons. I will drop into my third season of touring with the Plum Sok bindings in 2026 with absolutely no hesitation. They’ve been reliable companions for the last 150 days and I believe they will continue for another 150.
For some riders though, the lack of cant may be a deal breaker. This might be a reality for those who absolutely need cant on their binders. Pair the Plum Sok with some forgiving boots or narrow your stance and you will be the owner of one hell of a sturdy pair of bindings.
If you are looking to pick up a pair of Plum Sok bindings, head on over to the Plum website.
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Black Sheep Adventure sports was provided with a free pair of the Plum Sok bindings to review. This in no way affected our opinion nor the review.
