sth 16 without inner springs

[unclebill]

The idea was to down din some skis for temporary use by someone else. These are sth 16's with driver toe and have double (concentric) springs. I couldn't find any info on it, but did find for some previous higher din models. So my method is maybe not that scientific, but I compared the torque required on the big screw to get to 12 din with both springs in. Removed the inner spring, applied the same torque and it took the indicator to 14. It seems the inner spring adds 2 to the din and the sth 16 becomes an sth 14 without it. So we set them to show 10 on the indicator which gave the 8 he needed. Seemed to work out fine but never needed to release during the trip so don't know for sure. I can't guarantee if this is accurate or even safe for that matter, but maybe useful info for someone else.

[ill-advised strategy]

pretty speculative without actually torque testing the binding.

[CaliBrit]

pretty speculative without actually torque testing the binding.

I’d agree.

[unclebill]

pretty speculative without actually torque testing the binding.

I would have to agree with that myself and would not have gone ahead with this at all without something to base it on. Others have described similar results with some of the older higher din sollys, and removing the inner spring resulted in reducing the din by 2 to 4 depending which one. My sth 16's have dual springs and sth 14's have just the single spring. So I didn't think its a real stretch to remove the inner spring from the 16's and expect overall din reduced by 2. Of course I have no guarantee that the large main spring is the same in both. And my method of checking isn't perfect but I think at least verified that there is a 2 or close to 2 din difference without the inner spring. I will see if someone can verify this though. thanks

[1000-oaks]

Of course I have no guarantee that the large main spring is the same in both.

STH16 main toe springs are same as STH14, but main heel springs are different. Just going by feel, removing the inner springs seems to knock off about 3, but you'd have to actually test it to know.

[unclebill]

STH16 main springs are different than STH14. Just going by feel, removing the inner springs seems to knock off about 3, but you'd have to actually test it to know.

Ok thanks thats good to know we were in the ball park. And that this is a solution that could be used to temporarily reduce the din for loaning or maybe protect an injury, subject to verifying a little better the actual amount of change from removing the inner spring. thanks

[jondrums]

Highly doubt you should do this calculation by "taking off 2" or "taking off 3". It would be more like DIN is some percentage of whatever it says - maybe 14 divided by 16. For example a reading of 10 would be 10*14/16 =~ 9. Going by 1000-oaks suggestion would be 13/16ths; reading of 10 ~= 8

[CaliBrit]

Highly doubt you should do this calculation by "taking off 2" or "taking off 3". It would be more like DIN is some percentage of whatever it says - maybe 14 divided by 16. For example a reading of 10 would be 10*14/16 =~ 9. Going by 1000-oaks suggestion would be 13/16ths; reading of 10 ~= 8

I just don’t think I would take the chance.

[ZomblibulaX]

Better solution: DIN range starts at 9. That's close enough to 8, and gives you a much better idea of what to expect from the binding than removing parts and making assumptions. Torquing the screw head doesn't take into account the condition of the boot sole and therefore won't tell you squat about release values. And that's assuming you adjusted the binding correctly.

Regardless of what the DIN indicator says, you won't know how much force it takes to release from the binding unless it's torque tested with the boot that's going to be skied in it. It is far from unusual for bindings to require adjustment from the initial setting to release within range, and for individual components to have different settings in order to release similarly. That's why its called calibration.

Not trying to jump your case, but if you're trying to get in the ballpark in this scenario, the binding allows you to get exceptionally close without taking it apart.

[tenB]

Sell the 16s, buy 14s for less and problem solved. Why play amateur physicist when your livelihood is at stake?

[unclebill]

Sell the 16s, buy 14s for less and problem solved. Why play amateur physicist when your livelihood is at stake?

I am all for safety and not taking unnecessary risks but I think that solution is a bit extreme just to loan them for one trip.

[1000-oaks]

Considering the DIN chart assumes average bone densities and strengths, it's kind of a rough guess for any particular individual. So if the chart isn't accurate to begin with, why be overly concerned that the binding settings match the chart perfectly? Just get "close enough" and ski. There are so many other dynamic variables in play, DIN setting isn't something to obsess about.

Adjust to what feels good to you, and run it. Even if everything is adjusted and functioning perfectly, things can still go sideways resulting in injury.

[Ted Striker]

^^^ bingo. Especially when the vast majority of trg posters run literally ridiculous DINs themselves.

[unclebill]

STH16 main springs are different than STH14. Just going by feel, removing the inner springs seems to knock off about 3, but you'd have to actually test it to know.

At risk of beating this topic completely to death, if the main spring in the 16 din version isn't the same as the single spring in the 14, maybe it uses the spring from the 12 and beefed up with the inner spring. Anyone know enough about that to say if that's the case? It makes sense to me that they would use something existing rather than completely different. Otherwise why incorporate the inner helper spring at all, simply use a stronger single spring.

[1000-oaks]

I stand corrected, was going by memory.

Toes:
STH12: Green, 22g, 3.93mm wire, white 1.88mm plastic shim
914/STH14: Blue, 24g, 4.05mm wire, white 1.88mm plastic shim
STH16: Blue (same as STH14), plus 7g helper, aluminum 1.55mm shim

Heels:
STH12: Green, 43g, 4.13mm wire, red shim
914/STH14: Green, 48g, 4.53mm wire, red shim
STH16: Green, 48g, 4.83mm wire, plus 10g helper, aluminum shim

916/STH16 Steel: big single spring in each end

[Ted Striker]

If you had the tools to measure the torque on the screw cap, why not fashion up a crude vermont calibrater with a torque wrench and a piece of scrap 2x4. You wouldn't need to know the spec, just the comparison.

[Bandit Man]

He needs an 8 and will not ski a 9? Holy heck. My recommended Salomon release value is an 8 and I walk out of STH’s at an 11. You are overthinking it.

[unclebill]

I stand corrected, was going by memory.

Toes:
STH12: Green, 22g, 3.93mm wire, white 1.88mm plastic shim
914/STH14: Blue, 24g, 4.05mm wire, white 1.88mm plastic shim
STH16: Blue (same as STH14), plus 7g helper, aluminum 1.55mm shim

Heels:
STH12: Green, 43g, 4.13mm wire, red shim
914/STH14: Green, 48g, 4.53mm wire, red shim
STH16: Green, 48g, 4.83mm wire, plus 10g helper, aluminum shim

916/STH16 Steel: big single spring in each end

Thanks alot for the info. I don't know if I'll need to do this again ever but good to know just in case. Maybe someone else might need to. And also that it doesn't seem like we did anything too risky, using them without the inner spring and assuming approximate 2 din difference.

[unclebill]

If you had the tools to measure the torque on the screw cap, why not fashion up a crude vermont calibrater with a torque wrench and a piece of scrap 2x4. You wouldn't need to know the spec, just the comparison.

Agree that would give a close enough feel for it. But it was likely a one off for that trip. It all worked out and nobody died. I had thought of taking them into a shop to verify and then realized how trying to explain the whole thing would go. "Sir we'll have to confiscate those for your protection and ours".