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Belt deflection gauge

Discussion in 'Motorcycle Tech Talk' started by cardboard, Nov 6, 2013.

  1. cardboard

    cardboard Well-Known Member

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    I have a Motion Pro Gauge I use.

    Do you guess or do you use a gauge ?


    cardboard, Nov 6, 2013
    #1
  3. Lucifer

    Lucifer Well-Known Member

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    Was thinking about using a fish scale...but usually just set my finger to 10lbs and push:)once you take the play out it's hard to push...
    Lucifer, Nov 6, 2013
    #2
  4. Fatboy128

    Fatboy128 Well-Known Member

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    I have the Harley gauge but I wound up using the tried and true I.F. Gauge. (Index finger)


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    Fatboy128, Nov 6, 2013
    #3
  5. charlie46

    charlie46 Well-Known Member

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    tight-good,,loose-bad.
    charlie46, Nov 6, 2013
    #4
  6. FLHTbiker

    FLHTbiker Moderator Staff Member

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    Just crank it down so there's no movement either direction, then, just right :D That way no fingers needed and no slipping occurs. :confused:
    FLHTbiker, Nov 6, 2013
    #5
  7. cowboy

    cowboy Moderator Staff Member

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    the finger gauge works just fine , book I think says 1/4 in play ,Have to set bike a certain way & adjust
    cowboy, Nov 6, 2013
    #6
  8. joshbob

    joshbob Well-Known Member

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    We're talking about final drive belt "slack"? I've always heard tight is better. BDL primary drive belt calls for 1/2" to 3/4" movement total in both directions (at the center) for a 1 1/2" belt. No tool needed, just a ruler.
    joshbob, Nov 7, 2013
    #7
  9. Fatboy128

    Fatboy128 Well-Known Member

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    Technically for final drive 10 lbs of pressure should be applied to belt to measure deflection distance when the rear suspension (unlike you tough guys some of us like a softer ride ) is compressed with a rider sitting on the bike and the wheel is spun to the tightest point on the belt.


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    Fatboy128, Nov 7, 2013
    #8
  10. joshbob

    joshbob Well-Known Member

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    I learned something new. Didn't know you could measure final drive belt deflection with a belt tension tool - always thought it was a certain distance, like the way I measure my primary belt deflection. Interesting . . .
    joshbob, Nov 7, 2013
    #9
  11. Lucifer

    Lucifer Well-Known Member

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    It is Josh...with the tool you put 10lbs of pressure on the belt,then measure deflection/slack or play...whatever you want to call it... 5/16"-3/8" on the ground,no rider or 1/4"-5/16" on ground with rider on....maybe I'll use the fish scale to check and see if my finger is calibrated properly;)...
    Lucifer, Nov 7, 2013
    #10
  12. Lucifer

    Lucifer Well-Known Member

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    Only $25-$30 for the tool,so it wouldn't break the bank....since I have a new belt going on,I may just get one....Piano wire tight is hard on the mainshaft bearing and too loose you can break the belt....
    Lucifer, Nov 7, 2013
    #11
  13. joshbob

    joshbob Well-Known Member

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    . . . and shear belt teeth off. Yeah, a happy medium is what to look for. Riders who use a primary belt have been known to wear the tranny shaft bearing out with too much tension on the belt.
    joshbob, Nov 7, 2013
    #12
  14. FLHTbiker

    FLHTbiker Moderator Staff Member

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    I'm lucky that I have a lift table. That way I can easily check the belt by first using my center lift to get the rear tire off the ground and that way I can rotate the wheel and check for any cuts to the belt then I make air pressure check and clean the rear wheel. I then set it back down and check belt tension. I think inspecting the belt by rotating it around is also very important every time you check tension.
    FLHTbiker, Nov 7, 2013
    #13
  15. chucktx

    chucktx Moderator Staff Member

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    wonder where cb got the cash for his new tool?????? hmmmmmmmm??
    chucktx, Nov 7, 2013
    #14
  16. FLHTbiker

    FLHTbiker Moderator Staff Member

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    His wife of course :rolleyes:
    FLHTbiker, Nov 7, 2013
    #15
  17. cowboy

    cowboy Moderator Staff Member

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    He skiped his turn of buying Beer at the rally ,gotta pee be right back three time in a row
    cowboy, Nov 7, 2013
    #16

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