790 chain slack? What's correct?

Discussion in 'Parallel World (790/890)' started by Greg di, Jun 26, 2020.

  1. Doctor Zed

    Doctor Zed Resident

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    Seems like quite a bit of effort to get it to "about 10 -15 mm of play":dunno
    #21
  2. AdvRonski

    AdvRonski They call me......Ronski

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    It depends on whether you want to damage the transmission and rear wheel bearings from having the chain too tight, or actually learn the ideal chain tension to shoot for. You get to choose.
    #22
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  3. Norduro

    Norduro Thumping

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    The video below shows that for the 790 adv R there is pretty much zero difference in chain slack over the whole travel of the suspension. For me, this means no reason to pull the shock and what not.

    #23
  4. Dan D.

    Dan D. Long timer

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    Hey now...

    Some people like playing with greasy chains... No hate. :p
    #24
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  5. roookie1

    roookie1 Been here awhile

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    Just get two of your fat friends to sit on the bike, that will get you to the point of most tightness..
    #25
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  6. WI-790R

    WI-790R Been here awhile

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    For me, disassembling/reassembling a motorcycle is part of the fun, and consider the removal of a shock to be no big deal. Some of us will do that and go into the shock, to see what one shim difference in the stack feels like.
    #26
  7. Doctor Zed

    Doctor Zed Resident

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    Hopefully you guys never need to do a trailside chain tightening.
    I'll stick to what works for me you guys do the same.
    Happy riding:ricky
    #27
  8. AdvRonski

    AdvRonski They call me......Ronski

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    This guy had the right idea, but executed it poorly. He's running his chain very loose, so there's little apparent change in tension. The idea is to bring the swingarm up to the tightest spot, when the swingarm pivot, countershaft, and axle centers all are in alignment, then adjust the chain to have very little slack. Now, you can see what kind of slack a properly adjusted chain should have, for whichever method you prefer to use. I prefer to check when on a centerstand, as this is the most repeatable method. Using a trackstand, or checking on the sidestand has more variables, such as fuel load and cargo weight.
    #28
  9. chrislitt

    chrislitt Drinking the Orange Kool-Aid Super Supporter

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    Very helpful discussion and appreciated. Put that new 15T damped sprocket on and felt like a fool trying to make sure tension was right. Read the manual and the sticker. I’m sure it’s an intelligence test and I feel like wouldn’t have passed without this help! Whoops, I said “sprocket” again.
    #29
  10. TrailTrauma

    TrailTrauma Nemophilist Supporter

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    @chrislitt , how's this for esoteric? :D
    #30
  11. chrislitt

    chrislitt Drinking the Orange Kool-Aid Super Supporter

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    @TrailTrauma, I'm touched you thought of me! Pretty much "touched" anyway. I caught up on the suspension thread and marveled at a number of things. Towards the top was @AdvRonski's technical knowledge, his curiosity, and his willingness (and ability and tools) to take his bike apart and put it back together again, over and over again. So, pulling the shock to watch the chain tension change wasn't surprising and I had found the video he posted while trying to decipher KTM's instructions. I'm thinking maybe one man's esoteric is another man's floor?

    I didn't insult you did I? Would not be my goal ever.
    #31
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  12. TimTyler

    TimTyler Makes MOTOTREK

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    Note he unknowingly has the chain tensioner backwards at the beginning of the video.

    chain.jpg
    #32
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  13. TrailTrauma

    TrailTrauma Nemophilist Supporter

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    I dig your humour, and writing style. You'll fit in well with the rest of the wingnuts we have in here nicely :beer


    And that's a good analogy ... esoteric versus basement (as one's starting point). @AdvRonski is one hell of an asset around here. Shakes fist at clouds some days, but that too holds it's charm. It lets the rest of us slackers know we're ... slacking.


    The calibre of contributions in here is rich to the point of being well beyond humbling.
    #33
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  14. chrislitt

    chrislitt Drinking the Orange Kool-Aid Super Supporter

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    Whew!
    Right on in terms of caliber. And if it gets boring, which it hasn't, one can always go the fairing thread. In fact, I gotta go over there and post a photo of the Tripleclampmoto Straightahead brace. Thanks for the kind words.
    #34
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  15. Yellow Pig

    Yellow Pig Allergic to asphalt! Supporter

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    There is no such thing as the wrong way with the axle adjuster.

    It's just a question of sprocket size, chain length and desired wheel spacing.
    Wheel further back = bike more stable at high speeds.
    Wheel forward = bike more maneuverable.

    [​IMG]

    I have 2 sets of wheels. One with more aggressive tires and a bigger rear sprocket for hardcore off-road, and one set of wheels for road work with a smaller sprocket for better mpg and a higher top speed.
    I swap freely between the two and just flip the adjuster depending on the wheel set.
    #35
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  16. AdvRonski

    AdvRonski They call me......Ronski

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    That's pretty funny, TT!
    I do wish those goddam clouds would stop pissing me off, though.
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  17. braaap!

    braaap! Long timer

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    ^
    windmills too... maybe :)
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  18. TrailTrauma

    TrailTrauma Nemophilist Supporter

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    #38
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  19. atasic

    atasic Adventurer

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    I actually stick to manual procedure, for my level of understanding pretty clear too. I typically comply with OEM engineering written procedures. Also, procedure taken on long trips is portable enough out of the owners manual, where what you are suggesting becomes cumbersome on the road.
    I maybe arrogant by your label. I make living flying 986000lbs aircraft and design aircraft avionics. We write procedures for crews to use our systems in a particular manner due to safety risks. We expect our procedures to be followed exactly as written. I give the same benefit to KTM engineers, they designed the drive system, I follow what they write, not that hard to understand.
    #39
  20. AdvRonski

    AdvRonski They call me......Ronski

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    It's always interesting to hear from those in the engineering field. I usually see a certain rigidity in their approach and attitude around a subject. In this case, it's a little surprising for some reason. To be clear, pulling the shock and setting the chain tension at it's tightest spot is a one-time procedure. From that, you can use whatever method you prefer for subsequent inspections. I have found on my other KTM's, that 3 fingers width on the top of the swingarm is an easy gauge. On the 790, 2 fingers on the bottom side of the swingarm works for the 270mm travel suspension. The KTM manual procedure is done with the rear suspension weighted, by using a trackstand, which introduces the variable of fuel load, meaning the chain tension will not be the same, depending on how far the suspension compresses. Checking on the sidestand has more variables, depending on what kind of a load is strapped to the bike. The only reliably repeatable method is to have the rear suspension unloaded when checking chain tension, even this will vary between bikes, depending on the suspension travel. So, in my experience in owning close to 50 motorcycles in the 50+ years I've been riding and racing, this method is the most reliably accurate.
    #40