Hello everyone!
I recently got a pair of skis with Dynafit Low Tech Light (or Race) bindings (old type heel unit with 4 screws, like these)
http://pistehors.com/news/ski/comments/0704-low-tech-returns-to-its-roots/
The toe piece is the “classic” Dynafit (5 holes) with the plastic base (crampon holder)

The binding is mounted for 311mm soles, however my boots are 284mm, so I have to re-position the binding.

Comes the problem:
It’ll be a home mount, since there’s no shop where I live. The only template I have is for the front piece. For the rear I have none. So, I was thinking of not re-positioning both pieces, but to leave one piece in place and move the other.

So my options are:
A) Re-position the toe piece, but then the centre of my boot will be about 2.5-3cm off the centre of the ski, towards the tail, ie I’ll have “more ski” to the front.
B) Re-positioning the heel piece, but this will result in being 2.5-3cm off the centre of the ski, towards the tip.

How will these two positions affect the behaviour / stability / turn initiation (and whatever else one might think of) of the ski?

Last but not least, the bonus question:
what is the necessary gap between the LowTechRace heel piece and the sole of the boot? (in classic TLT Speeds they use a 4mm shim)

many thanks in advance for all the replies and help! 

George

The only template I have is for the front piece. For the rear I have none.

Would one of these templates help?

http://www.tetongravity.com/forums/showthread.php/153971-Binding-Mount-Paper-Templates

Oceanic - 26 January 2013 04:30 PM

Would one of these templates help?

http://www.tetongravity.com/forums/showthread.php/153971-Binding-Mount-Paper-Templates

thanks for the link, however at first glance it appears that most are for TLT speed. I’ll print them and check with the actual binding.

Any comments regarding ski behaviour if I left one unit in place, and just moved the other one?
(less drilling for me, less holes on the ski, smaller risk of getting it all wrong)

cheers!

I’ve not looked at the low tech in detail but aren’t all dynafit, and plum, the same mounting pattern?

ise - 26 January 2013 09:36 PM

I’ve not looked at the low tech in detail but aren’t all dynafit, and plum, the same mounting pattern?

as fas as I know, Dynafit TLT Speed (the “classic” binding) and Plum Guide have the same pattern.
Plum Race 145’s base looks similar to the Dynafit Low Tech Light, but only from pics I can’t tell. Thanks for the tip, though, I’ll look around the web for Plum templates

Did you already check your boots in the toe piece to see exactly where the center line would fall on the ski? This may give you some food for thought. There are also techniques for determining the “true” center of the ski, google for these. May be that moving one or the other is more favourable for keeping a more centered position.

In general place one ski on its tail, the other on its tip, vertically and split the difference between the center marks. Add this distance to the center mark. This gives you the ski’s true center, it will often be quite a bit forward of the ski’s center mark. You want to be back from this mark, further back lets you get the shovels out of the snow when skiing powder, too far back and you get less grip on hard snow as you can’t apply pressure. You probably want to be 4-8cm back from the true center. This should give you an idea which bit of the binding to move, I suspect the heel piece.

If you can mark the center of the ski you can pretty much use the heel unit as a template for drilling. I believe you need 4mm gap like the TLT speed binding, maybe someone can confirm? Obviously as you can’t fore-aft adjust this is going to be a nervous job!!!

davidof - 27 January 2013 12:33 AM

Did you already check your boots [...] this is going to be a nervous job!!!

Thanks for all the advice. By the looks of it, I’ll be relocating only the heel piece. Hopefully I’ll be able to use the two (existing) front holes as the new rear ones. This will make alignment easier. More on that in the next few days.

In the meantime, can anyone cofirm the 4mm gap issue?

thanks!

EDIT

Just spent about 1.5hrs testing new postions (without drilling, of course!)
I took both pieces off the ski and did all the measurements from scratch.
Unfortunately, it is not possible to use existing holes, for just a few mm.  :(

If I align the midsole with the centre of the ski, I’ll have to drill all 9 holes, some are just a few mm from the existing ones. So, I think this is not an option.

If the heel piece stays in place, midsole ends up 7-8mm to the back of the centre,
If the toe piece stays in place, midsole is 7-8 to the fron of the centre.
any suggestions?

Also, I put the Race performance planks (161) next to my Dynafit Guides (163 / 113-78-100). Both have different positions of the centre of the ski. In the race performance it is further to the back.
Any comments on that, please?

cheers!