From New Telemark Guide
Rottefella of Norway introduced their New Telemark Norm (NTN) system in early 2007 to an eager but skeptical sport of telemark skiers. The system's objective was to provide a freeheel telemark ski binding that featured lateral release, increased lateral rigidity, tunable performance, and free-pivot touring functionality.
Contents |
Binding
Rottefella's NTN binding skis with much great performance while exhibiting several features in one package unlike other telemark binding designs.
Rottefella's NTN Binding generally has to 3 main parts: The binding itself, a subplate that attaches the binding to the ski, and a heel riser. The binding sub-plate allows one set of NTN bindings to be used among any number of skis. Users only need to purchase a 2nd ski kit and mount them on the new skis. The binding can be removed by loosening a detent screw (which also allows some small amount of fore-aft adjustment) and sliding the binding off of the subplate. To mount the binding on another set of skis, the user simply slides the binding onto a subplate and tensioning the screws in one of three detent positions.
Sizing
As for 2010, Rottefella's NTN binding specifies 32.0 mondo and smaller. NTN bindings break down to two sizes: Small (for boots 26.0 mondo and smaller) and Large (boots 26.5 to 32.0). Boot manufacturers however may not provide all possible sizes. Currently, we've only seen them offer boots 24.5 - 30.5
Revisions
The NTN binding has see 2 revisions since its introduction. Revision numbers listed below are not official Rottefella numbers, they are simply unofficial designations assigned by the user community.
| Model | Official Model Year | Appearance | Revisions | Issues |
|---|---|---|---|---|
| 1.0 | 2007-2008 | Light translucent green w/red elements
Orange powdercoat w/silver lever | Debut of NTN product | Easily stripped detent set-screws
Powertube design superceded |
| 2.0 | 2008-2009 | Orange powdercoat (glossy) w/orange lever | Official Rottefella changes document
Heelpiece height reduced Powertubes feature knurled dial end and etched preload index marks along length | |
| 2.1 | Midseason 2009 | Orange anodized (matte) | Main frame channel lightening holes are slightly different.
Frame top edge has curved shape so that it is closer to the white flex plate Frame strengthened near the main pivot Heelpiece plastic climbing bar is a narrower Second heel retaining mechanism improved | |
| 2.2 | Late 2009-2010 | Orange anodized (matte) | 6-screw mount plate. Frame modifications. |
Subplates
NTN Subplates for mounting the binding to the ski has come in several versions. The sub plate versions are different from the main NTN binding versions as several plate styles have overlapped changes with the binding itself.
| Version | Characteristics |
|---|---|
| v1.0 | Cut outs to reduce weight. 1set of 4 holes. |
| v1.1 | Cut outs to reduce weight. 2 sets of 4 holes which can support K2 inserts. |
| v2.0 | Solid plate with no cutouts. 2 sets of 6 holes with support for K2 Inserts |
| v2.1 | Solid plate with no cutouts. Only one set of 6 holes and does not support K2 Inserts |
Boots
See NTN Boots.
Tuning and Performance
Much like other brands of conventional 75mm telemark bindings, NTN uses cartridge compression springs to provide boot retention as well as resistance to pivot, and like those conventional binding springs, optional spring rate cartridges are available to change the activity performance level of the binding. Rottefella calls them "Powertubes."
Powertubes: Selectable Activity Level
Powertubes are what Rottefella calls the metallic tubes that contains springs for NTN bindings. They are essentially compression spring cartidges. Powertubes can be adjusted and swapped for different tensions by the user. See Selecting the Right Powertubes for spring suggestions. The tubes are marked along the body with index marks. When rotated, the spring is preloaded and the index mark that appears in the window of the binding indicates the preload level.
- White - Extra Soft
- Green - Soft
- Blue - Medium
- Red - Stiff
- Black - Very stiff (Black tubes were once available with NTN's debut but are no longer being manufactured as of the 2008/2009 season.)
Release Capability
The NTN binding is capable of lateral release (side to side) although it is not rated using any recognized standard (DIN, TUV, etc) The amount of lateral force required to release from the binding increases with preload of the Powertube, as does the "activity" level of the binding. Therefore, if a skier preloads their Powertubes to setting 4 for a high level of activity from the binding, he/she can expect the release to require much more force than if the Powertubes were preloaded at setting 1. It is for this reason that most NTN users recommend using a stiffer Powertube set to a lower setting, rather than a softer Powertube set to a high preload setting (unless the objective is to prevent release.)
Known Issues
Binding Failure
There have been recorded breakages, although it should be noted that vintage, differences in use, frequency of use, care and maintenance, and general ham-fistedness of owners can affect the reliability and longevity of bindings.
- Broken toe cup (NTN 2.1 @ 80 days)
Boot Failure
The cracking shell issue on the Scarpa TX Pro 2008-2009 was widely publicized. This has been fixed however, and no reports of breakage for the new production run have been reported. The newer TX-Pros have become a popular model.
Spring Failure
There has been one reported instance of springs breaking from rust. A possible remedy is to store the skis/bindings pointed down (i.e. tips down instead of tips up) so that any collected water in the springs can drain.
Tips and Tricks
Check out the NTN Tips and Tricks page.