Ski bindings: DIN settings and compatibility

The release value in plain terms

A ski binding does two opposite jobs: it holds the boot through every carve, bump and hard landing, and it lets the boot out when a fall twists it beyond a safe load. The dial that balances those jobs is the release value, still called DIN after the German standards institute whose scale the whole industry uses. Every alpine binding carries numbered indicators on the toe and heel pieces; a higher number means more force is needed before the binding opens. Most adult bindings span roughly three to ten on the scale, junior models sit lower, and race oriented bindings climb well beyond what recreational skiers need.

Getting that number right matters in both directions. Too low and the ski releases in a nothing fall, which means lost skis on steeps and surprise ejects mid turn. Too high and the ski stays attached through a slow twisting fall, the mechanism behind many knee injuries. The correct value is not a guess or a bravado setting; it comes from a standardised chart.

ISO 11088 lays out the procedure a shop technician follows. The inputs are body weight, height, age, boot sole length in millimetres, and a declared skier type. The chart first assigns a skier code from weight and height, using whichever points to the more cautious row when the two disagree. Age shifts the code for skiers under ten or over fifty. Skier type then moves it again: type one for cautious or lighter skiers, type two for most skiers, type three for aggressive or fast skiers, plus a beyond chart step for experts who accept the consequences. Finally the code is read against the boot sole length columns, because a longer sole gives the boot more leverage over the binding springs. The result is the release indicator value for toe and heel.

Why a shop sets it

The chart is public, and a skier can look up their own row, but a correct setup involves more than turning two screws. The technician also sets forward pressure, which positions the heel piece correctly for the boot sole length, checks the toe height or anti friction pad where the design needs it, and then function tests the assembled ski, boot and binding on calibrated release equipment that measures the real torque needed to open the jaws. Shops record the signed off values, partly for your safety record and partly for their own liability file. If you own your skis, a first setup at a shop is the baseline; after a boot change, a noticeable weight change or a crash that damaged anything, the system deserves a re-check. Self adjustment is fine for a deliberate change you can explain, but treat it as the exception rather than the routine.

Alpine, GripWalk, MNC and touring bindings

The biggest compatibility trap on a ski trip is the boot sole, not the binding brand.

A classic alpine boot has a flat, hard sole defined by ISO 5355, and every plain alpine binding is built around that shape. GripWalk boots carry a rockered rubber sole that makes walking in lift queues and car parks far less slippery; that sole follows ISO 23223. A GripWalk sole does not fit a plain alpine binding: the toe sits at a different height and the contact under the boot changes, so release behaviour is compromised. The fix is simple in the other direction, since a GripWalk labelled binding accepts both GripWalk soles and flat alpine soles without adjustment, per the maker’s specification.

Multi norm certified bindings, usually marked MNC, go further and accept alpine, GripWalk and touring soles under ISO 9523. For a skier who owns more than one pair of boots, or a family sharing skis, MNC is the flexible choice.

Pin or tech touring bindings are a different world entirely: they lock onto metal inserts moulded into the toe and heel of a touring boot, so any boot without those inserts cannot click in at all. Many lightweight pin bindings also release differently from alpine bindings and do not carry the same certified scale, while hybrid touring designs pair alpine style toe and heel jaws for the descent with pins for the climb. Frame touring bindings take a regular alpine style boot and hinge the whole binding for walking, trading weight for convenience. If the trip is piste only, an alpine or MNC binding is the right tool; pin and frame systems earn their weight on human powered days.

When renting, the shop handles this matching for you, which is one reason rental remains the low risk option. Owners of GripWalk or touring boots flying to a resort should not assume every demo binding fits; say what sole you have when you book.

Brake width and fit to the ski

The brake is the spring loaded arm that stops a released ski from sliding away. Its width has to clear the ski’s waist when the arms fold down on release. The rule of thumb: pick a brake listed at the ski’s waist width or a little wider, commonly up to about 15 mm over. Too narrow and the arms cannot deploy past the edge; too wide and they drag or catch on firm, steep snow.

Mounting matters as much as the brake. The binding is positioned for one boot sole length, so switching to a boot with a different sole length needs at least a heel track adjustment and sometimes a full remount. Demo and rental bindings sit on adjustable tracks for exactly this reason, which is how rental shops refit the same ski for a queue of different boots.

Renting versus owning on a trip

Renting stays the simpler path for anyone skiing a week or two a year. A rental package includes bindings already mounted on adjustable tracks, the shop sets the release value from your declared details at pickup, and the system is inspected under the rental shop practice standard, ISO 13993. You also skip the airline sports bag entirely. Report your weight, height, age, boot sole length and skier type accurately; the setting is only as good as the numbers you give.

Owning pays off for skiers who travel often or who care about a familiar release feel. Own skis fly in a padded ski bag with the bindings still mounted; strap or band the brakes so they do not spring open in transit, and pad the tips and tails. The boots belong in the cabin, since they are the hardest item to replace with a good fit. After any flight or a long off season, a shop inspection before the first day is cheap insurance: look for cracked housings, bent brakes, loose mounting screws and a heel track that still slides. Bindings age, and manufacturers publish service windows after which shops may decline to adjust or indemnify a model, so a setup old enough to be refused at the bench is a setup to replace rather than force. The middle path many frequent skiers take: own boots and helmet in the hold or cabin, rent the skis and bindings at the resort. The Real Buyer Experiences pages linked above compare current binding models and explain the release system in more depth.