DIY Dynafit Hammerhead TTS

[Vanilla-Chinchilla]

Here's a teaser. Skinning and skiing it tomorrow at a local mountain and will try and post a little something up as to what went into it. Pretty self explanatory overall, but I'll include some more pics. Very psyched, and initial tests make it feel pretty close to an axl... Ski ya later, Luke

Also, open to creative names for it... so far I am referring to it as...

Sharknado

[bobbytooslow]

That looks great! Very clean. Almost looks like it shares the OMG TTS mounting pattern. Does it? Where does your pivot point line up on the HH 1-5 scale? It'll be interesting to see if any ice builds up around the round-head screws; they're kinda right in the compaction zone. Some countersunk flatheads might fare better. Or you might be totally fine.

I was gonna call my Hammerhead rip-off the "Scammerhead." Or, since I've had to include some pink Bombshell parts, the "Glamourhead." I haven't gotten around to finishing it, though, so those names are fair game.

[Rodbelan]

Just by looking at it (the pivot location), I think this one isn't going to be qualified as «neutral». It sounds like what you are looking for though... Hope you like it

[Grant]

Could the Dynafit toe have been mounted right on the black HH riser or is the HDPE necessary?

[Dostie]

Vanilla,

Although it seems hard to imagine the beta HH had a similar post to what you have. Actually, it had washers on the outside to keep the cable from popping off. Unfortunately those washers became saw blades and regularly cut the cable. So Rainey routed the cable through a channel. You may need to duplicate the channel concept. Hopefully not. Otherwise, it looks awesome!

Looks very clean!

[cesare]

Very nicely!

Dostie, you have a memory like a steel trap. I had forgotten about the washers and the posts.

[telemarkmark]

Here is my direct mount. Just resin filled in the cavities in the blue plate and screwed directly in. Works fine.
You may find that your pivot point is too far back, I started there, them moved forward.
Interesting too hear if your cables stay put, you do have the advantage of possibly being able to remove the cable and spring for a long climb. You may find that the tight radius of the pivot is a problem.
i only have experience of Freedoms, and a few days on Freerides, but do think that the HH Dynafit’s hard to beat.

[telemarkmark]

Ps
small block to support boot.
ski is a ScottyBob Headrush

[Vanilla-Chinchilla]

Sorry for the delay, been working out the final details and skiing, and just plain working as well (boring!!!).

A little about me and what I set out to do with this project:
I grew up in the Aspen valley and started telemarking freshman year of high school. I was of the new school variety including hitting the park every day and thinking clothes that didn't fit me right were cool on skis. I went to a high school with a telemark team and was coached by some of the hardest hitting freeheelers to hit the slopes. I picked up on what they were throwing down and skied a lot during college and afterwards have spent the last 4 seasons at Alta keeping up or smoking my alpine buddies (tele will never die!!!). I ask a lot of my gear, especially my bindings/boots/skis combos, which is typically T-races/axl with stiffy Springs/110 underfoot skis. I'm still apprehensive that pin toes will carry us to the next realm, but I thought it was worth a try, not to mention I had an old set of hammerheads laying around with stiffy springs, so using those parts was a no brainer. Boots I'm using with it are a well worn pair of 29 Scarpa Tx Pro (orange and Black).

There are simpler ways to do this, as TelemarkMark pointed out and I appreciate his simplicity and adjustability. I wanted to create a new sole block with plastic to accommodate a few features. 1) by creating a new block out of uhmw I could adjust where the spring seats and I now have an extra ~10mm of spring travel bringing it to about 70mm of total possible travel. 2) I could have the possibility of removing the heel assembly/spring from the binding when skinning (didn't work in it's current setup, but shows promise). 3) By making it 2mm wider, the HH cable essentially squeezes the sole block, nullifying any necessity for keeper washer (aka knife like Dostie says).

I am hesitant to put a HH 1-5 value on this setup because it ramps up so differently than I remember the hammerhead doing it. I'd say it starts around a hammerhead #4 and quickly becomes a #5-6 as you progress through travel to about 30-40 degrees.

The fulcrum is at 76mm back from pins and significantly lower. I've noticed this gives the binding a very progressive feel that ramps up quickly as the boot moves through its travel. I would appreciate a more stiff linear curve, but they do ski very well overall. I've hit some jumps, skied moguls, and even done jump turns on an icy groomer just to see if I could break it or get a release. They've performed flawlessly, but I should note, it is not possible to get knee to ski. Not by a long shot, but tension conveniently ramps up about as low as I ever go with some travel left to accommodate sucking up bumps. 60-65mm would probably be a great spot for all around skiing, especially nice cruising soft snow.

Grant, the dynafit could be mounted right to the block of plastic, but I was concerned with the strange forces I imagine this all puts on all the parts of this setup. If I'm going to spend any time on this setup away from the crowds or on hut trips, I wanted to screw the dynafit straight to the ski through the plastic to ensure there are ample inserts to hold down everything that's going on. What's the point of creating this thing if I rip it out 10 miles from humanity and my alpine friends all laugh at me?

Bobbytoslow, I'm not worried about icing as I skinned in some totally heinous conditions that should have made icing occur and it didn't, but a little pam cooking spray before a tour has always treated me well with preventing icing in my Axl's.

A note on uhmw - This stuff is weird. Delrin is an obvious alternative that probably acts far superior. The ethylene I used deforms slightly, has no resistance to drilling/routering and is really slippery. But it's way cheaper, so that makes it worth it I suppose.

Mounting Pattern - The mount is setup so that I can use any ski already drilled for either 22 designs bindings or the newer 4 hold Dynafit pattern without the holes overlapping. As long as one set of holes is present it is easy to mount based on those ones, it just requires taking the bindings off multiple times to get all the screws lined up correctly.

I'll try and take a pic of the boot flexed in the travel. Any upgrades would include the possibility of a shorter fulcrum to pin distance with the addition of ball bearings and that would allow the spring assembly to be removed.

Overall I am pleased with how this binding came out and honestly surprised it works. Also, I'd never actually skinned in anything other than axl's before... Dynafit toes are totally cheating! Now I know how all my friends have smoked me for years on the skin track. Now it's my turn to lay waste to them in both directions!
Happy skiing and happy to answer any questions or thoughts. Also, many thanks to all who previously posted regarding the DIY pin TTS systems.
Luke

[Grant]

Thanks, V-C. I was thinking long screws through the toes, through the riser, and directly into the ski.

[telemarkmark]

I found that The Dynafit’s toes raise the height above the cable guide, the effect is that the cable guide has to move forward.
Can you explain the ball bearing?

[Allan Fici]

VC, The binding looks good overall. UHMW has some good properties as it’s slippery but it’s soft. Delrin though more expensive has better structural properties and is very slippery with the Teflon component. If you use Delrin you could mount the toe to the block with either inserts or tapped #12AB screws then mount the block to the ski with the 6 hole 22D pattern. The rear 4 screws are on the 22D pattern correct?

I have a plastics supplier who lets me pick thru their drops pile and buy small scraps of Delrin for a very good price. It’s 4 hours from where I live so I don’t get there very often.

The cable pivot position is also relative to the BSL so shorter boots would use a shorter cable pivot to tech pin line.

[Vanilla-Chinchilla]

Sorry, been out and about. Skied these things down a big scary line the other day and they performed admirably! The Pivot position is too far back, but I've been lazy about drilling a new hole and it's boating season now.

The concept with the bearings was to give the pivot location friction free movement as it slides when the boot is flexed, but I think it unnecessary now that I've put some plastic spacers on there.

Allan, Yes, the rear 4 holes are in fact 22 designs and I spaced them so that I could use the rear 4 holes on any 22 designs mounted ski and put 4 more dynafit inserts without hitting the front 2 axl holes. For simplicity sake, take 2 will definitely involve delrin and putting inserts straight into it so that I can move it easier. Also, mounting using 2 different hole patterns is scary and takes so long!

Concept proven, I'm a believer!