Wilbers-BMW: 0-1

Discussion in 'GS Boxers' started by tagesk, Jun 30, 2013.

  1. fred flintstone

    fred flintstone Long timer

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    +1 There are a whole cascade of things that happen when you need to increase the shaft diameter. As I am sure you know. One of the simplest, for people who have not worked in this industry is the gas pressure. Larger shaft means larger shaft cross sectional area relative to (floating) piston area. This reduces amount of attainable peak damping force (PSI*diff area). Also INCREASES static gas offset force (PSI* shaft area). But then to get more peak damping force you have to increase internal gas pressure. That increases the static offset force as well as raises internal stresses on seals etc. etc.

    It really is a very involved design trade off, and as someone else said you better have a good reason to want the larger diameter shaft as a primary concern and then be willing to accept the compromises. But the thing is it increases stresses on other parts while at the same time the extra loads you'd want it for in the first place also does that.

    FYI I used to work for/with a guy who made custom automotive racing shocks, and rebuilt other high-end shocks (Penskes Ohlins etc.) for major pro teams. I learned a lot but certainly no expert. Enough to know how complicated this is and how much of a black art in many ways. Any reputable high end aftermarket shock manuf has put in many thousands of hours minimum in design trade offs and computer sim CAD time on exactly these issues.
    #41
  2. Mr. Canoehead

    Mr. Canoehead Taste Gunnels!

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    You could at least smile TaSK! For a guy that just got a Christmas present in July, you look kinda PO'd. :lol3
    #42
  3. tagesk

    tagesk Tuscan rider

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    That's my "I'm impressed"-look.
    My "This is cool"-look can be seen here.
    :rofl

    [TaSK]
    #43
  4. fred flintstone

    fred flintstone Long timer

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    Hey Mr. C what up? PM'd you.
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  5. Schlug

    Schlug JockeyfullofBourbon

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    put something on and stay in that position.

    Whoa buddy. Let's make it clear that no one was indicting you or your years of experience, so you can take a deep breath.

    I just don't believe that Wilbers decided that a smaller shaft diameter was a good idea based on that information. I think they probably had that shaft from a previous shock and thought it would work fine on the GS, which is clearly not the case. It sounds like precisely the sort of answer invented afterward to justify such a wispy component.

    I just spent 6,100 miles, two-up and loaded for 3 weeks of camping on my 1150, riding some really stupid trails which they called 'unmaintained roads' one day (four crashes) and 91 mph super slab out of Montana the next. All of it two-up and loaded. I am certainly happy that my shock did not fail. Nor did my fluid boil, seals blow, or high pressure detonate the shock body.

    I'll stick with Ohlins.

    PS
    Happy TasK wasn't hurt when his shock failed. And I'm really happy he received a new shock for free. But I wish he would sell that thing and install something else.

    What if next time he is injured-- who will maintain the GSpot FAQ?

    (not it)
    #45
  6. Mr. Canoehead

    Mr. Canoehead Taste Gunnels!

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    You mean the same Ohlins that failed so spectacularly on Long Way Down?

    Things fail, it's an imperfect world. but I don't see a rash of Wilburs failures being reported.

    He got 200,000km on his Wilbur and a free replacement. That's pretty good.

    Sent from my SGH-I747M using Tapatalk 2
    #46
  7. fred flintstone

    fred flintstone Long timer

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    #47
  8. JustKip

    JustKip Long timer

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    Wilbers = 14mm
    Ohlins = 14mm, but can be upgraded to 16mm @ no charge (according to Jim at "OhlinsPro")

    They break right at where the threads are cut into the shaft, and the 16mm shaft has more material left after threading (obviously)
    #48
  9. JustKip

    JustKip Long timer

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    BTW; I was told that Wilbers and Yacugar are the exact same design, and that the 2 engineers who designed and developed them at a firm in the Netherlands each own one of the brands. And that both use the same subcontractors for components.
    #49
  10. fred flintstone

    fred flintstone Long timer

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    I read something like that recently elsewhere, thanks for the info on diameters.
    #50
  11. trc.rhubarb

    trc.rhubarb ZoomSplat!

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    Hyperpro and Yacugar are the same product. Wilbers is it's own but rumor is many of the engineers for all 3 came from WP before KTM got em.
    #51