Chain Slacking Off Doing My Nut In On 959

Discussion in 'Technical Help' started by Ohferfeksake, May 20, 2023.

  1. Anyone with a Panigale out there have to adjust chain every 150 miles? Surely this isn't right? Any thoughts on why?
    ...so i've owned a 959 for a couple of years now and from day one the chain has slacked off ridiculously quickly (bought at 5k miles, 17k now). I assumed the original chain was just cack so fitted a new chain and sprockets after a couple of months ownership (Afam sprockets and top notch DID zvmx chain) but it made no difference whatsoever, still goes out by 10mm of play in a couple of hundred miles. I always torque the axle to spec, keep it clean and lubed so what the hell is going on? I've just got back from a 1600 mile trip round Ireland to the NW 200 and had to adjust the chain everyday. I could really do without having to carry a 36mm socket and torque wrench with me when I go further than my local pub. Any bright ideas?
     
  2. I can’t help but somethings not right. I’ve never had to adjust the chain on my 959 in 4500 miles and I do check it!
     
  3. If the chain is good it can only be other factors, like axle moving.

    I’d go back to basics and review how you adjust the chain, how much slack is there, make sure all tight etc. not wishing to be rude but more likely user than mechanical issue unless you are mega unlucky.
     
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  4. I know this might sound silly but….. any teeth missing damaged on either sprocket, can be missed and would do what you are describing, I speak from experience, some hard dirt accumulated above the front sprocket, dropped and damaged rear sprocket, that was 20 years ago, now I clean drive system and all associated areas methodically. You never know .
     
  5. Couple of thoughts..
    Are you checking tension after you’ve torqued the axle nut? As the nut is tightened down, the swingarm compresses very slightly and the chain tension changes, only a small amount, but it will move.
    You can negate this by adjusting the chain with the nut snugged down rather than being loose.
    After you’ve tightened the nut down, tighten the adjuster screws up to the adjuster blocks. For the same reason above, as the arm sides compress, the blocks won’t be tight against the adjusters.
    Are you doing the axle up to torque? 180Nm.
     
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  6. Not dirt or broken/worn sprockets as I am absolutely OCD about cleaning, sometimes a lot of shite round front sprocket but this issue is consistent even after deep cleaning and when sprockets were brand new. I always torque to 180nm spec, snug up adjusters and always re check after final tightening of axle nut as yes it does often throw it out again. Also this problem occurs just the same if someone else (ie tyre fitter) does the job so I don't think it's just me being a fuckwit. The only other thing to mention is that there is a very big range in slack between the tight and loose spots on the chain, and that was true on the original chain and sprockets. I always take my 42mm slack measurement from the tight spot and err on the tight side.
     
  7. is there anything you can mark with tipex or something after tensioning to make it visible if something is backing off?
     
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  8. ...something's moving but God knows how or what.
    In other news, bike drops off for Portimao on Saturday and a shock eye bearing is toast and they can't be replaced (WTF?!). Bought a cheap 1299 shock last week as someone here reckoned you could swop the springs, but this turns out to be wrong (for reference if it helps anyone, 1299 shock is same length but spring, shock dampening centre-can and spring retention rings are all a fair bit wider and spring is a inch shorter on so no way a 959 spring goes in a 1299 shock).....so, looking for a cheap and very quickly posted 959 shock in good nick, failing that either I put the shock with play back in or the over stiff 1299 one and see If it's possible to get the sag right.
     
  9. Yeah that's not a bad idea, maybe Mark alignment notches to see if axle is moving.
     
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  10. did mine recently

    undid the 36mm bolt

    undid locking adjusters

    adjusted each about a quarter turn at a time, both sides until tension was a ok

    locked adjusters in place

    checked slack

    retorqued the 36mm bolt

    if thats any use, i believe above someone torqued nut then locked adjusters?
     
  11. if you already have tight spots, then its time to change the chain already i think.

    I had a similar experience on a 999 which for some reason the chain had differing tight spots, and the chain let go and destroyed swingarm, casings, Exhaust and numerous carbon nick nacks...

    without a 959 to check, whats the axle alignment like when you look from rear to front sprocket when the top chain run is at eye level (crouched behind the bike, looking along the top of the chain)

    from my own experience alignment, tension, lubrication and being parked up for extended times has impacted chain tight spots occurring

    i always err to the looser chain adjustment, rather then towards the tighter end of the scale.

    but as you have mentioned that you also have Shock Eye wear, then it would seem something is not right, without your comments above about adjustment i would have thought the chain is too tight and passing vibration / load into the suspension.
    worth getting it checked to make sure nothing is bent etc
     
  12. Some early bikes in the Panigale series had sprockets that were going oval, which can cause all sorts of issues
     
  13. Hmm, thanks all, I will eyeball the alignment and check for runout in the sprockets, an oval sprocket would account for a bad tightspot and more likely than chainwear on an 18 month chain I would have thought. Got a new shock coming from Bettes btw, hope it gets here by Friday.
     
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  14. I had a similar problem once with a KTM 990 SMT, Bike had done 9,000 miles when we went on a 10 day French trip , everything checked before and all looked good to go :upyeah:
    Half way through the trip I had to adjust the chain, okay, no biggie, but I had to adjust it again the day after, and the day after that :thinkingface: ???
    After about 3 days of constantly adjusting the chain and relentless piss-taking from my mates, the first clue emerged,….the rear wheel was covered in a fine silvery dust deposit :confused: turns out it was the sintered rollers in the chain breaking down and creating massive wear in every link, by the end of the week the chain adjusters were fully out and it was still slack, just managed to nurse it home the last day, KTM OE chain, utter cheap garbage!
    Just as a side note, I’m not a fan of DID chains either , the last two I’ve had on have both developed tight spots early in their lives, so I’ve now got an RK Takagaso blackscale chain on, we’ll see how that one goes
     
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  15. Any chance you can slip the chain off and spin the wheel, just to see what's happening (ovality/wonky/whatever) with the sprocket?
     
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  16. My 959 can’t say it’s been n issue after about 1500 track miles. I have got DID chain which I put on when I got it as the original was pretty gunky and had a tight spot or two so not sure about standard ones etc
     
  17. Update. Took the old chain and sprockets off and have replaced. No noticeable run out in sprockets, chain was at max recommended stretch but no more (measured 17mm or 1% longer than new on). So none the wiser, new chain has significant tight spot again but not insane like old one had got. We shall see if slackening off persists....
     
  18. Why has a new chain got a tight spot?
     
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  19. That's a good question !

    OP has new chain and sprockets but the problem remains !
    " That's some trippy sh*t homes " ( ...... Pulp Fiction quote ?? )

    I can only think of two sensible explanations -
    Either the rear sprocket carrier is not running true , or less likely , the gearbox output shaft isn't .
    My question would be :- how often does this tight spot come around , compared to one rotation of
    the rear wheel ?
     
  20. Could this have allowed the complete swingarm to move and hence the rear wheel/sprocket/carrier/chain to also move excessively?

    How about some other wild left field guesses?Swing arm bearings? Rear shock linkages? allowing the same movement?
     
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