Update: I got this spreadsheet going for some binding delta (ramp) numbers. Note, we’re trying to adhere to a convention here in calling the binding angle “delta” and the angled created by the inside of the ski boot the “ramp.” We’ll gradually editing to that effect. If we’re talking about the combined delta and ramp angles, we’ll probably call it “combined ramp angle.”
Know that due to how tech bindings work, the following numbers are not the binding delta as you would measure with an alpine binding, are are the distance from ski top up to the center of tech binding pins. Thus, the numbers are for comparison between different tech bindings. For real-world concept, know a couple of things: For a tech binding to provide the somewhat “neutral” or “Zero” delta angle of a zero angled alpine binding, you’d have to raise the boot toe up about 1.5 centimeters. (For any boot, due to location of toe and heel tech binding pin sockets.) That’s a huge amount, and enough to cancel out much of your climbing lift. Instead we’re working with smaller increments, and tend to use the old TLT binding delta (or a bit less) as our baseline goal. My measurements are accurate to within a half mm or so, all to the centers of pins both toe and heel.
My favorite delta angle is equal to or a bit less than the original Dynafit TLT models: heel of boot is stacked about a centimeter higher than toe. What I like about this configuration is it gives some forward lean power to ski boots that are otherwise quite “flat” and may walk comfortably but need a bit more lean when latched in the binding and headed downhill.
All fine and dandy…but, you can have too much ramp and lean for today’s style of skiing. The ramp of the earlier TLT bindings could be considered excessive. Later Dynafit models such as Comfort, Vertical and Radical added even more height at the heel and in many people’s opinions most certainly have too much ramp. Other brands of tech bindings tend to have quite a bit of ramp as well, though you’ll find choices in toe shims that reduce ramp (such as with some configurations of Plum bindings.)
Goal this year at WildSnow HQ is to improve our skiing and preserve our knees. So I want a more relaxed stance; less tippy-toe 1970s herky jerk — more Stephen Drake. Furthermore, I’m sick of jumping from ski to ski and adjusting to different ramp angles, so I’m standardizing my quiver at the TLT angle or a bit less. That way my in-house skis will all feel familiar, and when I’m at demos I’ll still be used to some ramp and won’t get thrown forward when I step into an unshimmed pair of Dynafit Radicals or other ‘rampy’ tech bindings. Thus, a pre-season project: tuned ramp geometry on all our ski setups.
First, lets go over the shim stack thickness requirements I got from a digital caliper session in the WildSnow shop (these could be a tiny bit different than previous blog posts, due to how measured, but such small variations make no practical difference for real world ramp-angle tuning). Below ARE DONE AS A COMPARISON TO TLT AS BASELINE. (Actually specifying the exact ramp angle of a binding involves how it interacts with a given boot, so we’ll leave that one for another blog post.)
So, Dynafit older TLT models are my baseline. But they have an obvious ramp angle of boot heel higher than boot toe. If you want virtually neutral ramp add about 3 mm to the shim thicknesses I list below. Bear in mind that as you shim up the toe on tech bindings, you cause an equal reduction in the height of your climbing heel lifters. Along with their toe shim plates as shown in the photos here, B&D ski gear sells some solutions for that (see photo below).
Vertical ST/FT, Comfort, shim toe up about 5 mm to equal same as TLT, or go thicker for neutral ramp.
— Recommendation: Use B&D shims.
Radical ST/FT, and Speed, shim toe up 3 mm to equal same as TLT, or go to virtually neutral ramp by adding thicker.
— Recommendations: Custom made 4 mm shim, or for virtually neutral ramp use 6.5 mm FT/ST toe plate with Speed model, or B&D shim plate with Radical FT/ST.
(Note, I measured difference in heel/toe heights as accuratly as possible on Radical and early TLT, most accurate difference I could come up with is that Radical has 2.84 mm more heel height than TLT, so round that up to 3 mm)
Gorilla in the room is your screw lengths. For example, add a 3 mm shim and you need 3 mm longer screws. A couple of solutions.
1. B&D sells longer screws to go along with their 6.5 mm shim plates. If you shim to 3 mm, you can order these screws and cut the tips off (grind down and re-sharpen).
2. The longer B&D screws also work for stacking their plates with Radical bindings.
3. When shimming the Dynafit Speed model, simply use screws specified for Radical models.
4. If you’re a total DIY, you can use generic wood screws to mount bindings. Get best match at hardware store and cut to length. If necessary trim diameter of head by chucking the screw into a drill and running against a file or sanding block. Torque carefully and use epoxy.
5. With thinner skis, always check ski thickness vs screw length by using calipers. Trim screws that are even a hair too long to avoid risk of ski damage.
Ergonomics: Ski style, foot size and more will change your perception of binding ramp changes. If you are primarily doing muscle powered skiing, I recommend smaller changes in ramp angle. If you do a lot of mechanized laps and thus have ample time to experiment, try everything you can. Bear in mind that the Dynafit binding models with the most excessive ramp are the Vertical FT/ST and the Comfort. These bindings are what inspired B&D to make their shims, which drop the FT/ST/Comfort ramp back to that of the TLT. Along with that, know that the shorter the boot the more ramp angle for a given stack height difference between toe and heel — hence folks with small feet may experience the most detriment from rampy bindings. Lastly, skiers with multiple skis to choose from will benefit by standardizing their binding ramp angle.
Shop here for B&D products. The shim plates weigh 30 grams (1 ounce) without the front and rear tabs, which weigh 8 and 12 grams respectively.
Below is info for the Dynafit OEM Radical binding toe plates, available from dealers or direct from Salewa NA. Both plates are the same thickness, ST plate recommended for stack shimming.
ITEM DESCRIPTION ITEM #
FRONT BASE PLATE (SPACER) ST 48580 9999 $15.00 (30 grams, has reinforcing web underneath, recommended)
FRONT BASE PLATE (SPACER) FT 48581 9999 $20.00 (28 grams, hollow underneath for vibration damper)