790 chain slack? What's correct?

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

  1. atasic

    atasic Adventurer

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    Thanks for clarifying. I actually appreciate your detailed explanation. I have no doubts you are correct on the procedure and nuances. Yep, you are correct on rigidity. :) Nature of the beast. We are all wired that way in that field.
    #41
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  2. Winston Rose

    Winston Rose Adventurer

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    Hi all,

    Swapped my 1190R for a 790R recently. Only been able to get out on her a handful of times (5/6) thus far but whilst I am waiting for better riding days I thought I'd check out the ADV rider forum and see what the common issues/ fixes people have going for these bikes.

    I've only had the bike a month and already I've had a couple bizarre .. happenings. For another thread.

    Anyway!

    About this chain slack talk. What. In gods, name is going on here?

    Adjusting the chain on the motocross bikes is,
    1. Put bike on stand & Undo axle nut,
    2. loosen off adjuster nuts
    3. Tighten chain to ~four fingers of slack above the swingarm.
    4. Tighten nuts
    5. Tighten Axle Nut.
    6. Ride

    1190 process.
    1. Put bike on centre stand (The greatest invention since sliced bread)
    2. As above. Drop off centre stand, looking for ~40mms of slack with side stand down.
    3. Ride

    When you're away from home and doing a trip with big milage, you check the chain at every fill-up, and end of day once tent is up and beers are out... adjust if needed.

    Has something major changed with this new bike?

    Genuinely curious!
    #42
  3. windblown101

    windblown101 Long timer Supporter

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    Dang, I'm really slacking (pun intended). I check my chain slack once or twice shortly after putting on a new chain and then only when swapping tires.

    As for method. I find whatever works and provides repeatable results and then use it. On the 790 I push the chain up towards the bottom of the swing arm if it hits the swingarm it's too loose. If I can stick my finger between the chain and swingarm it's too tight. If it starts making strange noises under load it's time for new sprockets and a chain. :)
    #43
  4. TrailTrauma

    TrailTrauma Nemophilist Supporter

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    This may be good info for those having their suspension stretched, or those purchasing the Rally suspension components - to recheck chain tension post install.
    #44
  5. Dan D.

    Dan D. Long timer

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    My new method is "make it flush"

    Ask me again tomorrow, I'll have a better idea then.

    PXL_20210121_224540910~2-01.jpeg
    #45
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  6. windblown101

    windblown101 Long timer Supporter

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    *glances sideways and goes to kitchen for a drink*
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  7. Dan D.

    Dan D. Long timer

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    Confused.

    But based on this and your ocala comment, just trolling?
    #47
  8. windblown101

    windblown101 Long timer Supporter

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    Not trolling. I figured you must be kidding, but perhaps not? If not then if it happens to provide the correct slack now what happens as the chain wears and stretches a bit? How does the chain remain properly adjusted? What happens if you drop a tooth on the front sprocket or add teeth to the rear? Perhaps I'm the one that is confused?

    As for the Ocala/Croom comment - I actually love to head to Florida during winter for some riding and have done so every year for the last 5 years. We don't have sand here and I suck in sand. I take the little bike and have a go at it though. Awesome fun and a change of pace. Watching someone who knows sand sling a 790 around the tight whooped out narrow tracks in full on Rally mode would be a treat. Seriously.

    My little 250 has almost all the power I can handle there and gets on top of the sand at slower speeds so it doesn't scare me much. A 350 might be a little better to fight bogging, a 500 would probably just get me in trouble. I'd almost surely end up in the weeds multiple times on the 790 trying to go fast enough to not plow the front.

    From my last trip down - I shot some video when I pre-road in Ocala a bit as a warm up before heading down to Croom and Richloam.



    Now back to our regular scheduled programing...
    #48
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  9. Dan D.

    Dan D. Long timer

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    Ah, gotcha...

    That's why i said, "ask me again tomorrow and I'll have a better idea then"

    It's a moving target.

    Thanks for the clarification.
    #49
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  10. Electorn

    Electorn Adventurer

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    This video has been mentioned in the thread I think, but seach YouTube if not:
    "KTM 790 Adventure R - checking chain tension by raising the swing arm"

    I asked the question how long the bolt is, he replied it is 2 and a 1/4 inches long. I will be using this method from now on.
    #50
  11. Winston Rose

    Winston Rose Adventurer

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    It's manually adjusted by you. You do realise those bolts are there to compensate for the chain stretching over its lifetime? The chain doesn't just remain the same length from day one to its last trip?

    If you swap out a sprocket on the front, for instance, you put your bike back together again and adjust the chain. When you swap tyres, you put the wheel back on, and check your chain slack again.

    Oh and @Dan D. I don't know if you already know this (I assume you do) but the axle block is that shape so you can spin it around and get more life out of the chain. You ideally want that bolt to show through that hole somewhat and not disappear into it.
    #51
  12. Dan D.

    Dan D. Long timer

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    :)

    Thank you sir.
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  13. windblown101

    windblown101 Long timer Supporter

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    I'm aware. Thanks?

    My point was that adjusting the bolt bottom to be flush with the back (as shown in the photo) "may" happen to result in correct slack in one specific scenario by shear chance, however, it should not be used as a basis to adjust for proper chain slack as it does not take into account any number of variables.
    #53
  14. Winston Rose

    Winston Rose Adventurer

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    Alright, apologises @windblown101. Your message read (at least I read it) as though you thought otherwise. (As well as the fact you say you only check your chain after installing it and at tyre swaps!)

    I agree with you in your last response that, Dan having that bolt where it is, isn't great. Spin that axle block around as I said and you should get a bit of that bolt showing through the hole.

    And, perhaps when I re-read your first reply @windblown101, what you might be asking, is how does he compensate for needing to slacken his chain further after swapping out a smaller front sprocket?

    My answer, as above. 180 on that axle block. Once you get to where you are again now @Dan D. with that much bolt disappearing. Time for a new chain set!
    #54
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  15. windblown101

    windblown101 Long timer Supporter

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    As for the block. Yep. I swap them around depending on the wheel, gearing, and chain length I'm running.

    I may come off like I'm clueless at times (sometimes even intentionally) but I've actually been at this game for a bit. ;)
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  16. Dan D.

    Dan D. Long timer

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    EnchantingOldAmericanavocet-max-1mb.gif
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  17. Dust 'n Noise

    Dust 'n Noise Adventurer

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    I have been riding and racing as long as @AdvRonski but not as many bikes. My system as well.
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