Raising the Front Binding.

[jbotti]

A piece of credit card thick plastic taped to the bottom of your boot will work and not interfere with the function of the bindings.

That is true for the heel but not the toe. The general rule is never add shims to the toe.

[Svend]

A piece of credit card thick plastic taped to the bottom of your boot will work and not interfere with the function of the bindings.

Ha! My wife will be happy to cut up one of my cards, shape it to the contours of the boots, and epoxy it in place, never to see the till at a ski shop again....    Remind me not to show her this post.....

[jim-ratliff]

That is true for the heel but not the toe. The general rule is never add shims to the toe.

Ok, your credit card is safe. Heed what john said.

[Svend]

Svend:

it's an interesting topic.  3mm of plastic shim under my heels made a world of difference in my balance, and getting me out of the back seat.  Now I just have to leverage that with technique and body angles.

Jim

You're right, this is an interesting topic.  In this sport, I'm repeatedly astounded at how much difference a seemingly miniscule measure can make on performance and comfort.  A couple of millimeters here, one or two degrees there, and a ski or a boot can feel totally different, for better or worse. 

Re. your heel shims, interesting that you should have experienced the opposite of what was stated below.  Some people obviously get their hips shifted forward when adding toe shims; others need heel shims to get the same effect.  I guess there is no universal rule here.  Every body is unique....

[ToddW]

Svend,

Someone mentioned a 2mm temporary shim under the toepiece.  That exceeds the DIN tolerance (toe height 19mm +/-1mm) for boots and could cause troubles.

warning: long-winded response

Since you asked, my fore-aft alignment has always been done by highly trained alignment specialists.  I've gotten to the point where I can say in the shop what lateral alignment will end up right after on-snow tests as the result of getting aligned in several boots.  But I don't have that feel for ramp and forward lean and probably won't ever.  It's something of a black art.

In my current Heads, I have a 4mm external toe lift and a very small heel lift.  The heel lift is because of the way my foot fits inside the boot during big fore-aft recentering movements, not because of limited dorsiflexion.  It's a very tiny (and recent) tweak to maintain full contact when I flex deeply or just wind up "back there."  To give you an idea how small, it was originally a few plies from a paper napkin grabbed from the Black Mountain Lodge at A-Basin.

By contrast, the same alignment process wound up putting 1.5mm toe lifts inside my old Nordicas and spoilers behind the cuffs.  The difference is due to quirks of anatomy and boot design.  (I also had a 0.5* and 0.25* change in lateral alignment switching to the Heads.  Quirky interaction of boot design and anatomy again.)

Without the toe lift, I get the feeling that my feet want to slide down to where my toes are.  Since I'm in tight, foamed plug boots no actual sliding happens but the sensation still occurs.  Imagine standing facing down a handicap access ramp in loose sneakers.  Up to some pitch, you wouldn't notice much.  And then there would be a huge difference between trying to take weight on the ball of your foot, under the arch, (or under the heel.) It loosely coincides with the onset of the sliding feeling.
 
In boots, the "natural response" to too much ramp is to either plantar flex (baaad stuff) or to seek the back seat, which doesn't do much to alter that sensation, i.e. it doesn't fix a thing and just makes matters worse.

My alignment guy suspected I needed the toe lift based on my previous alignment and on how I stood in the boots on flat ground.  We took out short demo skis (160cm) to accentuate fore-aft sensitivity.  They had the same bindings as my main ski, but shimmed 4mm under the toe binding.  We skied together for about 3 hours from flat to steepish (1st week of November; limited terrain), with and without shimmed bindings, and with a variety of turn sizes before finalizing the fore-aft alignment.

My body shape (short legs, long torso, extra weight up top) has a lot to do with needing the gas pedal.  Even so, if I had bindings with a low delta/"ramp angle" I might not need this fix.  But my beloved Supershapes by default come with Freeflex 14 which have a very aggressive nominal 7 degree ramp angle (the real racing freeflex bindings are 5).  To limit variability, the other bindings in my quiver have 5 degrees of ramp.  Switching skis midday, this 2 degrees is a very noticeable difference.  The powerrail 11 bindings that came with my Icon TT 80s have a nominal 3 degree ramp angle.  One day I may try them out of curiosity, but for now I switched to powerrail 12 with 5 degrees to limit fore-aft variability.

[Gary]

Hey Todd...you bring up an excellent point I think...I was just reading where switching skis for those with multiples, or even demoing, different bindings have different ramp and delta angles and could affect are likes or dislikes of that skis performance and whether or not we find our sweet spot.

Thinking back regarding my MX78's...switching from the Marker Griffon which is relatively flat to the Head Powerrail 12, all sorts of things were different....and by luck.....very positive performance results came out of the exchange.

Maybe someday the selection process will be a mathamtical solution. For now, it's discussions like these and experimenting that helps us find a way to locate that "sweet spot".

G

[Svend]

That certainly is an interesting point regarding differences in binding deltas.  I'm not sure what my Look PX12's and Markers are on my Dynastars and Nordicas, but according to the literature there is a +7mm delta on my Progressors with the Flowflex bindings (same as the FF14 that Todd mentioned).  Looking at the Tyrolia tech manual from a couple of years back, delta values vary hugely, from +3.5mm for the LD12, to a whopping +9mm for the Mojo 12.  This has made me curious about my other skis,  I will measure when I have some spare time.

Todd, thank you for the very detailed and informative response.  You certainly seem to be getting fantastic service from your alignment guy.  3 hours of on-hill assessment, and all that fine tuning.  Impressive!

In addition to bringing to light the differences in ramp angle, it was most interesting to read about the whole alignment path you went through, and how you came about making the changes.  You've given me some food for thought, and new sensations to be alert for.

And, no worries, I don't think I will be putting any temporary shims under my boots.  As far as that kind of tweaking goes, I'm going to leave well enough alone.