For '05 640 Adventure owners... all 200 or so of you.

Discussion in 'Thumpers' started by creeper, May 16, 2005.

  1. Arch

    Arch Incurable Gearhead

    Joined:
    Dec 30, 2001
    Oddometer:
    11,706
    Location:
    Katy, TX
    Your chain tightens with suspension stroke and it's more important to pay attention to how much slack the chain has when it's at its tightest. It works and it's easy to check, but other than that, nope, I don't have any good reasons for you, MP. :evil
    #81
  2. slide

    slide A nation with a future

    Joined:
    Jul 20, 2003
    Oddometer:
    21,408
    Location:
    NM, USA
    OK, you two got me curious. I'm going to set the catenary by the book (bike raised in the air) and then check with it fully loaded (me draped over the seat) to see what the diff is.
    #82
  3. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    I took a walk at lunch and a little bird whispered this in my ear:

    "The tightest point on any motorcycle chain is when a straight line can be drawn thru both sprocket centers and the swingarm pivot shaft. With a force of approximately 10 pounds applied to the chain at a point equidistant from the sprocket centers, chain slack should be 1/2" to 5/8" for ANY chain. This alignment point can be obtained by using tie downs to compress the rear suspension. After a chain is adjusted using this method, it will be confirmed correct when checked against the manufacturers method of adjustment."

    :wave
    #83
  4. slide

    slide A nation with a future

    Joined:
    Jul 20, 2003
    Oddometer:
    21,408
    Location:
    NM, USA
    OK, bird, why does there need to be any slack at the longest throw? I thought slack at point X was there so the chain was at zero or close to zero slack at the three element alignment (witching?) point.
    #84
  5. davewrit

    davewrit Been here awhile

    Joined:
    Jul 30, 2003
    Oddometer:
    106
    Location:
    Mequon, Wisconsin
    Thank you SO much!!!

    GREAT description!!!!!
    #85
  6. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    Well I hate to put words in the bird's beak but I could give you my interpretation. :scratch

    I think what the bird was trying to impart is the chain is tightest when all three are aligned (cackle) as you percieved. So if one were to set the slack to zero at full compression or when resting the chain would tighten as the swingarm moved thru the point when the three elements are aligned. This would stretch the chain and decrease its lifespan. I suppose it is possible the tension could exceed the chain strength and break the chain if the swingarm were long enough! :arg

    Therefore to set the chain at the maximum tension axiom stipulated by the birdy you must have these three aligned. Then birdy goes on to state the mfgs have accounted for this and given us an adjusted tension specification for our specific bike that does not require us to compress the rear shock - nice!

    The birdy managed to scratch this diagram in the dirt for me to ponder:
    [​IMG]

    Did I get it right?
    #86
  7. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
  8. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    i'll assume by "you" you meant the bird... :D I'm just the messenger (so don't shoot!).

    glad that's over and we can move on... :getiton
    #88
  9. slide

    slide A nation with a future

    Joined:
    Jul 20, 2003
    Oddometer:
    21,408
    Location:
    NM, USA
    I'm still not with it, but don't want to bug the bird any more. THanks for the diagram.
    #89
  10. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    :bluduh

    I am such a failure! The bird is going to scoff at me... :cry

    Hope you understand the chain is tightest at the alignment point; and if you tension it to the max spec at any other point (up or down) you be above that spec every time it swings through the alignment point...

    Well the bird did mention this as I walked by on my way home yesterday:

    "Free play changes as, among other things the temperature of parts change.
    The minimal play is required to compensate for expansion and contraction, and to maintain a layer of lubrication between the chains moving parts.
    In addition, transmission and wheel bearings would not survive in a "zero" clearance environment for very long."

    :wave
    #90
  11. slide

    slide A nation with a future

    Joined:
    Jul 20, 2003
    Oddometer:
    21,408
    Location:
    NM, USA
    (sigh) so here I am again. I see the driven sprocket moving along an arc thus shortening the distance from it to the c.s. sprocket. Thus, if the chain would loosen from the diagram to any other point on its allowable arc. Thus if there were zero play at the diagram point, there would be >0 play at any other point on the allowable arc. Thus, you can have no play at all at the diagram point if the chain can operate with 0 catenary (I dunno).

    I think that I'll take refuge in your last post about thermal expansion. We need slack at any point for that. Thus I retreat hoping to have held my head high with Mr Bird.
    #91
  12. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    you had me nodding all the way up to this fancy word: catenary - "the curve theoretically assumed by a perfectly flexible and inextensible cord of uniform density and cross section hanging freely from two fixed points" :scratch

    i know you got an LC4 (schweet 05 SXC ya bastage :D), like me (03 LC4a :ricky), and i know it has a spec in the manual for tensioning the chain while the bike is on the center stand (i think, i hope :lol3). why not use that? :thumb a wise bird once said to me in the park,

    "The tightest point on any motorcycle chain is when a straight line can be drawn thru both sprocket centers and the swingarm pivot shaft. With a force of approximately 10 pounds applied to the chain at a point equidistant from the sprocket centers, chain slack should be 1/2” to 5/8” for ANY chain. This alignment point can be obtained by using tie downs to compress the rear suspension. After a chain is adjusted using this method, it will be confirmed correct when checked against the manufacturers method of adjustment."

    can we go riding yet? :D
    #92
  13. ChrisC

    ChrisC Amal sex?

    Joined:
    Feb 25, 2003
    Oddometer:
    6,325
    Location:
    Prescott, Arizona USA Earth
    Fuck no Meat....let's overthink this a little more :freaky
    #93
  14. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    you bastage you!!! :ace

    alright!!!

    Direct quote from my 03 KTM LC4 Adventure Owner's Manual:

    Of course w/ static sag, they are playing it a bit loosey-goosey saying center or side stand... but maybe a hunny mms don't amount to much arc-distance stuff :uhoh and therefore tension.
    :deal
    #94
  15. creeper

    creeper Still alive...

    Joined:
    Dec 13, 2003
    Oddometer:
    10,718
    Location:
    Puget Sound
    :oscar
    #95
  16. braaap!

    braaap! Long timer Supporter

    Joined:
    Mar 16, 2005
    Oddometer:
    4,400
    Location:
    Here and There
    :rogue hey Meat, it really aint rocket science..... just adjust the fooker as per the Holy owners manual, you can believe what you read as the the guys that designed and built em told the guys who wrote up the manual, what to write....

    an' besides a 'catenery' is a little birdy isn't, some sorta little yellow sucker?

    Hasn't this thread been (hi)jacked-off? (excuse my dyslexia)
    #96
  17. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    I posted the bugger's directions directly above; that's what I am trying to convey here... WTF, you don't follow me either!?!? :umph

    no that's Tweety... gawd, don't'cha luv da peanut gallery? :smooch
    #97
  18. slide

    slide A nation with a future

    Joined:
    Jul 20, 2003
    Oddometer:
    21,408
    Location:
    NM, USA
    WTF??? A catenary is a furry feline which chases the birdie. The birdie can be one of those yellow cannery types which often give warning over torquing your steel bolts into an aluminum housing.

    I don't think we've beaten this one as much as the synth v dino oil debate, but we're pushing it a bit. I'm wondering when one will chime in calling someone else a chain catenary Nazi. :D

    -paul
    #98
  19. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,587
    Location:
    Circumlocution Office of Little Dorrit
    Catene (pl. ) of Catena Catena (n.) A chain or series of things connected with each other. Catenary (a.) Alt. of Catenarian Catenarian (a.) Relating to a chain; like a chain; as, a catenary curve. Catenary (n.) The curve formed by a rope or chain of uniform density and perfect flexibility, hanging freely between two points of suspension, not in the same vertical line. Catenated (imp. & p. p.) of Catenate Catenating (p. pr. & vb. n.) of Catenate Catenate (v. t.) To connect, in a series of links or ties; to chain. Catenation (n.) Connection of links or union of parts, as in a chain; a regular or connected series. See Concatenation. Catenulate (a.) Consisting of little links or chains. Catenulate (a.) Chainlike; -- said both or color marks and of indentations when arranged like the links of a chain, as on shells, etc.

    Ah! I get it! I think you meant the curve of the chain hanging between the front and rear sprokets... :evil Still not exactly sure what "0" catenary means but I think you need consider that all chains operate with some slack (well, even cam timing chains? Probably eh? I know they use a tensioner that I didn't tension in time on my 78 KZ1000 :cry).

    You MFG. has instructed you on how to tension your chain. If you doubt their veracity (:rolleyes) some here-say from a little bird in the park lays out the theoretical basis for chain tensioning in general so you can check the MFG's specifications and method.

    What more could a girl want? :choppa
    #99
  20. Nom de Guerre

    Nom de Guerre Long timer

    Joined:
    Nov 15, 2004
    Oddometer:
    2,034
    Location:
    Pasadena, CA
    You guys are really getting some mileage out of yankin' yer chains. :lol3

    FWIW, I use the manual's method. I do love the way nearly every non-KTM biker I encounter tells me my chain is too loose when they look at my bike parked on the centerstand.

    I used to take the time to explain the deal to them, but it happens so frequently that now I just say, "Oh... yeah, thanks. I never noticed that. I'll have to look into that." :D