LC4 Steering head bearing, a how-to-guide...

Discussion in 'Thumpers' started by laramie LC4, Sep 15, 2006.

  1. creeper

    creeper Still alive...

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    PM'd ya' sweetums. :wink:
    #21
  2. meat popsicle

    meat popsicle Ignostic

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    The expression "King for a Day" comes to mind :deal
    #22
  3. rapiti

    rapiti IOR Veteran

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    First, thank you Laramie! Creeps groupies were so impressed that they are lining up their daughters for you :thumb

    Castleman, I am about to do the same with my WP 5060s. I bought some Motorex 7.5w fork oil, and some new .50 springs from Cannon. Mine has but 6,500 miles, and I am encouraged by your description of clean fork oil. How much fork oil did you add? Maybe I should ask how close to the top did you fill each leg?

    Thanks,

    Paolo
    #23
  4. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    So laramie by any chance do you have the measurements for the bearings on the LC4...


    I'm making a frame and one of the last things i need is to make the head tube, i'm going to used KTM spects sice the forks are so popular and abundant


    thanks in advance
    #24
  5. meat popsicle

    meat popsicle Ignostic

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    Ricky,

    You can PM Loadedagain, he likely has those measurements. There might be a thread around somewhere with them as well, since the OEM bearings are 3x as much as those found at the local bearing supply shop, and I recall folks discussing the buh-jeebsus outa it.

    Building a frame eh? :evil
    #25
  6. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    Yeap and a strange one too...
    [​IMG]

    AS ussal thanks for the Leads, I don't know why I did not think about you guys before, since the GS forum this days is mostlly about Zimicrome and shinny blings..

    I was also looking on the Thummper treads about information of dog bones and rocker ars since I'm not sure what type of suspension to use on the new bike.

    Note: really chessy Muke-up at the moment just to test for space.
    [​IMG]

    Mister popsicle Can you suggest me the best place to search or even post the questions i need to ask.
    #26
  7. meat popsicle

    meat popsicle Ignostic

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    I don't even know WTF Zimicrome is! :freaky

    Anyways, making a new frame for a boxer - ambitious! I am always impressed by folks such as yourself who take on such challenges. Nevermind the fabrication, just designing the wheelbase, steering head and rear swingarm geometry, and all these things to work together - OK I am way outa my league, but I can have an appreciation of some issues! :beer

    I have not seen much discussion about such choices, probably because they are not easily modified, and very very few build their own. I could only offer that folks who have tried many setups seem to prefer the circa 2000 WP forks (the "extreme" RSU 50mm forks (sic)), and I have read that the (circa?) WP PDS shock was better (no dog bones?) - but this is just to get the ball rolling; there are many here more qualified than I to discuss this with you.

    I would try a post in Thumpers. Just don't show the boxer so Arch has to contemplate relocating you, or do and say that you are interested in thumper suspension setups. "Choosing Suspension Components" or some such title might get the right crowd to look.

    I might suggest "Equipment" but that forum seems to be more about Accessories. Maybe I should say:

    Builder's Forum Now!
    #27
  8. ChrisC

    ChrisC Amal sex?

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    [​IMG]
    #28
  9. meat popsicle

    meat popsicle Ignostic

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    :dunno

    I have it on good authority that the cat's meow is Plexus. :evil
    #29
  10. ChrisC

    ChrisC Amal sex?

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    Simichrome works bitchen on AL, don't know how it fairs with plexiglass (my guess is it would do fine.... ).
    #30
  11. rapiti

    rapiti IOR Veteran

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    Ricky likes moving parts!:D
    #31
  12. taffyscouser

    taffyscouser Adventurer

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    Would it not be a simpler fix to drill the headstock with a 5mm drill. tapp the hole out to M6 and insert a grease nipple. This way you pump the headtube full of grease and each time you feel the need pump some grease through those bearings and the shit should come out leaving new grease in there. Not done it to the hADV yet but done it to every other oil in frame enduro I have run and never replaced a head bearing on any bike.
    #32
  13. creeper

    creeper Still alive...

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    There's a potential down side to that... which is no visual inspection.

    A zerk can be a fine thing, but with a lot of people, having one means never looking at their bearings... and there are other reasons to look at head bearings besides cleaning them and greasing them.

    A visual inspection gives me an excuse to... visually inspect things. :D
    #33
  14. todd83-900t

    todd83-900t Been here awhile

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    Does anyone have any tips on replacing the lower bearing? Is this operation best left to those on the planet with big presses? My bearing has some surface corrision, no pitting, and I'm debating about whether or not to replace it.

    Todd '95 RXC 400
    #34
  15. creeper

    creeper Still alive...

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    They aren't a particularly tight press fit Todd... but they still can be a little snotty.

    To remove the bearing from the stem, get a pair of side cutters and snip off the cage. When that comes off and all the rollers fall off, you have a nice ledge to tap on with a punch and hammer.
    I've never needed any more that that to remove a KTM lower stem bearing but... if it gives you grief, you can try a heat gun to expand the race a bit.

    If you're referring to the bearing race, that can be removed with a long punch inserted from the top... or failing that, a long screwdriver that you don't like all that much anyway.
    To install a new race, a simple block of wood works fine. Tap, tap, tap it in and around even and seated. If you're race is a bit countersink in the head, you can use the old race as a driver to seat it the rest of the way.

    A few guys have made up an install tool from a piece of thread-all, a couple of nuts and an assortment of thick washers. Those work well, especially if you have an aversion to hitting things. Don't forget to put some anti-seize on the threads. :D

    C
    #35
  16. rapiti

    rapiti IOR Veteran

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    Chris shared a bit of his wisdom when I forgot how to use my tools a while back (and I'm not done yet! :D )

    I used a long drift to knock out the races, and tapped them in with a dead blow hammer and a piece of 6mm Baltic Birch plywood until they were seated. Cake.

    Good luck!


    #36
  17. creeper

    creeper Still alive...

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    You got a hammer? OK... who the hell gave rapiti a hammer?

    [​IMG]

    Christ! You know he'll just hit something with it!

    :huh ​
    #37
  18. mars

    mars Starbucks anyone?

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    question about bearing replacement, I need the lower bearing that i can get locally, does any one know if the lower seal is a standard item or do i have to buy it from KTM?
    #38
  19. Dotbond

    Dotbond Africa, Africa

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    Might check my bearings now Laramie has started on the road to becomming a god like creeper dude. :evil
    #39
  20. mars

    mars Starbucks anyone?

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    my lower bearing was a nasty goo of rust and grease.
    #40