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OB4: Please help with tension data

Than_BoganThan_Bogan Posts: 6,389 Mega Baller
I am working with OB4 to see if we can establish a simpler method of accurately setting the tension screw. To aid that effort, I am asking for every OB4 user to respond to this thread with the following:

The letter setting you believe you are using.
Your weight in pounds.
A caliper measurement of how much each tension screw extends beyond the housing. (Round to hundredths or leave that to me.)
Any comments about your skiiing style or how sure you are that your tension setting is ideal for you.

I'll start:

K
170
0.37" front and rear
I'm a shortline guy but not especially aggressive. I was very confident in my settings last season but have had some trouble getting back to the right spot this year, which is part of why I'm working on this!
Nathaniel Bogan -- GUT Padawan
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Comments

  • ALPJrALPJr Posts: 1,816 Mega Baller
    @Than_Bogan hopefully I'll be able to gain some insight from you and other OB4 skiers. I hope to have a package coming my way soon.
    Than_Bogan
  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    @jdk99 @JJVDMZN @BlueSki @Deanoski @desmonipoux

    Anybody? :smile: I really think this could be enormously helpful, but I need to get some data!
    Nathaniel Bogan -- GUT Padawan
  • jdk99jdk99 Posts: 96 Baller
    @Than …didn't have my calipers with me last few sets. WIll get you my data this week.
    Than_Bogan
  • BlueSkiBlueSki Posts: 633 Crazy Baller
    Same here. Should have a chance over the next week.
  • MattPMattP Posts: 5,982 Mega Baller
    .275 155lbs [email protected] Front system only. I am not usually still on my ski through the exit of the turn.
  • DeanoskiDeanoski Posts: 823 Crazy Baller
    Than you are over thinking this!!! every spring is different the only way to make sure your tension is correct is to do a dry land release test just like you would do for a reflex system.

    I test my front in a OTF then test the rear Out the back
    my rear spring tention is set lower than my front binding.



  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    @Deanoski I disagree on all counts. But perhaps you can convince me. How can you tell that the setting is correct based on such a test? I've attempted that and can barely feel the difference between dramatically different release settings. And Mike Mosley has told me he doesn't use manual release as a metric at all, and may not even be able to release from his that way.
    Nathaniel Bogan -- GUT Padawan
  • ggincogginco Posts: 100 Baller
    I just ordered this system and expect it to arrive this week. This thread isn't giving me any warm and fuzzies that I should trust it. Is this system still in heavy R&D stage?
    jcamp
  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    @gginco No I wouldn't say that. @mmosley899 has been using it for years. This discussion is more like fin settings for a ski.
    Nathaniel Bogan -- GUT Padawan
  • MattPMattP Posts: 5,982 Mega Baller
    edited June 2015
    I'm kinda with @Deanoski I would say my spring has undergone a lot of use and that my cam has been replaced a few times. I think there are a lot of variables involved when setting release tension with OB4 and with other systems. What works or one skier might not work for another. Does @Than_Bogan think too much into stuff? you betcha. Is it usually for a good reason? Sure. It's a lot like sharing fin settings between people and different calipers. It gets you close but at the end of the day it is what works best for you and your style.

    @gginco defiantly not in R&D. Tested for a long time.
    Than_Bogan
  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    Well said @MattP, although I am still optimistic that this measurement will be "fairly comparable" from system to system.

    Btw, a big part of my personal problem is that I am complete novice at setting a release tension period. I've been in rubber for decades, and I never became expert enough with snow skis to do anything but accept whatever the shop did.

    And I absolutely did outsmart myself when I first got these, but my goal with this current effort is actually to simplify for everyone. Overthinkers need simple instructions even more than idiots do!
    Nathaniel Bogan -- GUT Padawan
  • mmosley899mmosley899 Posts: 584 Water Ski Industry Professional
    The springs we use are very precision built to specific specifications. Than is researching whether we can use these measurements as a way to determine settings. I use a torque wrench to determine settings for each system built. The setting that each skier uses is dependent on a variety of factors and can be adjusted according to our chart and skier input. I have used the same springs in my releases for years with no deterioration of pressure.
    Mike's Overall Binding www.mobsystemrelease.com
    Sweet Home Alabama Skiing
    Senior Judge, Senior Driver, Tech Controller
    MattPThan_Bogan
  • JJVDMZNJJVDMZN Posts: 128 Baller
    Will send my info @Than_Bogan
  • JJVDMZNJJVDMZN Posts: 128 Baller
    edited June 2015
    @Than_Bogan , @mmosley899
    If you want more accurate adjustments, I suggest that the adjustment screw must be flanged / locked at the lowest setting (H) so that it cannot screw in deeper and the using shims to set the other 7settings (I-O).
    This way the adjustment screw cannot unscrew and change the tension.
  • JJVDMZNJJVDMZN Posts: 128 Baller
    JJ: Male
    Letter: K
    Weight: 171lbs, 5'11"
    Front: 0.324, Rear: 0.348
    Not aggressive, still learning at 46km/h (28mph)

    Aidan: Male
    Letter: L
    Weight: 163lbs, 6'1"
    Front: 0.301, Rear: 0.307
    Aggressive at 58km/h (36mph)

    Monica: Female
    Letter: H-I
    Weight: 158lbs, 5'11"
    Front: 0.409, Rear: RTP
    Not aggressive, still learning at 46km/h (28mph), she wants the boot to release easily.
    Than_Bogan
  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    Great info!! Am I correct that was the setting Aidan was on in that epic crash video where they released perfectly?
    He has the same build I do, so that's a great data point for me personally.
    Finally, have any of those been double checked with a torque wrench or just relative to where it came (K)?
    Nathaniel Bogan -- GUT Padawan
  • JJVDMZNJJVDMZN Posts: 128 Baller
    Yes that's correct @Than_Bogan
    I do not have a torque wrench, Aidan just wanted a higher setting, so I turned it in 1/2 a turn, when I turn it back 1/2 turn I get 0.340, the same as my rear setting
    Than_Bogan
  • jdk99jdk99 Posts: 96 Baller
    @Than. Current settings:

    185lbs

    .75 turn cw from factory both front and rear. Presumed L/M (60 ft/lbs). Torque not tested.

    Front: 0.262
    Back: 0:292

    Again, I'm either type b or c so still a little conservative

    NB. The factory mark on the rear doesn't quite line up cleanly w the mark on the housing so not sure it's accurate. Might explain length discrepancy
    Than_BoganJJVDMZN
  • Bookm_danoBookm_dano Posts: 84 Baller
    Hey @Than_Bogan ...finally got a chance to measure my tension screws today:
    180 Lbs
    30 mph novice
    32 to 34 mph open water
    Front - .361
    Rear - .359
    Could go a bit tighter but still shy from an ankle injury last year (which inspired me to buy the OB4s).
    Than_Bogan
  • BlueSkiBlueSki Posts: 633 Crazy Baller
    Finally got this done.
    178 lbs
    L on the OB4 chart
    .33 rear and .38 front

    Not sure why the difference is so great, I checked the marks from where Mike set if for me at 56 lbs when he changed the cams last year. The back had actually crept out a bit but I tightened it up before this measurement. Average intensity skier, deep 32 off.
  • JJVDMZNJJVDMZN Posts: 128 Baller
    Had an OTF with the ski twisting at 52km/h, both boots released but felt a slight pain in my left ankle (which didn't last long) from the ski's twist.

    To be safe I'm turning the tension screw out a 1/4 turn on the front (left) foot, this should put it closer to the rear setting of 0.348.

    My old settings
    JJ: Male
    Letter: K
    Weight: 171lbs, 5'11"
    Front: 0.324, Rear: 0.348
    Not aggressive, still learning at 46km/h (28mph)

    New Front: 0.340

  • ccoganccogan Posts: 4 Baller
    Just got my new OB4 System in the mail this week, so I can’t claim that I have any setup locked in at this point relative to what tension data is correct for my height, body weight, riding style (5’-10”, 165lbs, aggressive and mostly open water skier – 32mph). That said, just finished calibrating the tension springs with torque wrench and dry land release tests. You can see in the attached pictures that to calibrate the tension release, we bolted up a steel plate for testing to avoid any damage to the aluminum binding plates. Then welded a bolt to the plate to apply force with a torque wrench. Tried to position our testing point similar to what Mike Mosley demonstrates on the OB4 website.

    Found that the system as mailed to me was setup significantly tighter than setting K. The tension screw was screwed in almost completely and tested with our setup at +80 ft-lbs of torque to release. With some testing we found that 55 ft-lbs of tension correspond to approximately ~.21” of exposed tension screw (measured from the spring housing to the lip closest to the spring housing). You can see my crude measuring in the attached pictures, I will update when I have something more accurate to verify with.

    A note about comparing “calibrated release forces”. Unless I’m thinking about this wrong I believe that the point of the force application on the plate will have a dramatic effect on the measured tension setting (apply a rotational force as we did with a torque wrench, applying the force closer to the spring = higher tension release readings. Vice versa, apply the force closer to the pivot point/wedge = lower tension release readings).

    I’ll try to update when I’ve got more experience with finding the correct tension settings for me.




  • gregygregy Posts: 2,563 Mega Baller
    Good idea. Need to get a measurement from OB4 for attachment point on plate or you will not get the same readings. Also one on the concern I had was that the curve of the ski will cause a increase in spring compression. Test needs to be with plate on ski.
  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    edited July 2015
    That tension screw in the second picture is extremely loose (unless something is fundamentally different about your setup vs. mine). I would definitely not ski with it that loose!
    Nathaniel Bogan -- GUT Padawan
  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    You appear to be measuring the same thing I suggested, but that should measure between 0.5" and 0.7". At 165 lbs that would be prerelease city. I don't know why your torque measurement isn't the same as Mike's, but I very seriously recommend against skiing with it at that position until you have figured out what is going on. Somewhere around 0.35" should be right for you.
    Nathaniel Bogan -- GUT Padawan
  • ccoganccogan Posts: 4 Baller
    @Than_Bogan I'm confused by your last post. Are we measuring from/to the same points? Currently both screws on my setup measure ~.21" from the back of the spring housing to the first edge of the groove in the tension screw. BTW I haven't visited PreRelease City yet (it doesn't sound like a nice place), but i also haven't skied on it due to the 20 mph breeze here today.

    Side note - Are others dry land testing the release? With your current setups can you/how easily pull free from the ski?
  • Than_BoganThan_Bogan Posts: 6,389 Mega Baller
    The measurement I intend (and that i believe everyone in this thread is using), is from the base of the housing to the TOP of the screw.

    I am glad you saw my post.

    Now that i have fixed my setting (with help from this thread!), I can JUST BARELY force a shore release if I put almost my entire body weight against it. Since you are not doing shortline slalom (yet!), you could be a little looser. But the setting in your picture is waay too loose.
    Nathaniel Bogan -- GUT Padawan
  • mmosley899mmosley899 Posts: 584 Water Ski Industry Professional
    @ccogan I agree with @Than_Bogan the screw is too far out. I cannot verify that your test is the same as what we have done in our settings during build. I think that we need to develop a standard testing procedure for everyone to do their own testing, that is what this thread is about. I have never used a shore release by standing on the ski and trying to release/pull out the boot as a test of the system. Than's measurement is from the end of the screw to the housing. Mine is currently at .340 on front and .360 on rear. Somewhere between .350 and .375 should work for most skiers. You should just be able to see the first indicator ring out side of the housing as in my photo. There are two other indicator rings that can be viewed through the site window. You can see that the second ring is just visible in the window, and there is also a tiny puch mark indicating the position where we tested the tension.


    Mike's Overall Binding www.mobsystemrelease.com
    Sweet Home Alabama Skiing
    Senior Judge, Senior Driver, Tech Controller
    Than_Bogan
  • ccoganccogan Posts: 4 Baller
    Thanks @mmosley899 and @Than_Bogan for the quick advice, I will definitely be adjusting before the morning. I am a little puzzled at the moment over the difference in testing results. After drawing up a quick force diagram of the situation I no longer believe that the torque wrench application point should alter the release tension.
    Than_Bogan
  • gregygregy Posts: 2,563 Mega Baller
    @ccogan after I got to thinking about I not sure myself. Try flipping you adapter plate around see what it does to you reading.
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