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Any idea what would've caused this??

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Mike9999, Aug 14, 2011.

  1. Hey all,

    Ninja recently (2 weeks ago) had it's 12,000km service and a new rear fitted. Since I picked it up I've probably done around 600km on the road. Gave it a good clean earlier this week and found this at the back of the left swingarm:




    I have no idea how that screw got bent like that, and why the cap at the end, and the screw's nut, is missing I'm fairly certain that it wasn't like that when I picked it up from service, but I'm second guessing myself now. Anyone got any ideas?

  2. When the wheel was put back on, the locknut wasn't done up tight against the tension nut on the chain adjustment. After a while, the lock nut has vibrated lose, and off, followed by the tension nut. The cap has come out and slid down the tension bolt, but rotated so that the end (top / bottom) of the cap has hit the sprocket retaining bolts, forcing the tension bolt wide. This may have happened before the tension nut was fully off, so contact could have happened multiple times. Eventually, the nut and the cap have fallen off, leaving the bolt displaced as you see. If you examine the sprocket and retaining bolts and nuts carefully, you'll find little dents / scratches / marks where the cap has hit it. (edit - if the bolts and nuts are good steel and the cap was aluminium, perhaps all you'll see as a few little clean spots like someone's dabbed at it with a cotton bud, but there will be a contact mark somewhere.) Look at all the bolts, on the upper, inner side - closest to the axle and rotated slightly in the direction of travel. Take a few good clear close-ups, then get your spanners out and make sure the axle nut is tight, then take it (slowly, gently) back to the shop that did the work, and make big puppy-dog eyes at them. If they waffle - show them the photographs. Don't threaten to show the photos to A Current Affair unless they turn nasty. Just ask them if they can help you out here.

    [2nd edit] I can see a shiny spot right there on the lower one of those sprocket retaining nuts, in that last photo. It looks like sombody's tried without success to take off the nut with a cheap spanner, and it's slipped. Look for shiny marks like that on the others as well.
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  3. Wow, Kneedragon I think you've pretty much hit the nail on the head with that one, thanks!

    You were right, you can see the marks of the cap hitting the sprocket retaining bolts. I checked the sprocket nuts and thought I saw some marks that go in the direction of travel, on the inside surface, but it just turned out to be some dirt. That last nut you pointed out did have some marks but none of the others did. So I checked the bolt tips and saw some distinct, shiny marks, and even a dent in one of them (last photo). Here are some pics, not the best quality, but I've circled the spots in red:



    Just above the axle nut, on the top face of the swingarm, is this scale:


    That bracket with the large notch on it seems to have moved a couple of mm back from the centre line of those smaller lines. (edit: difficult to see from that angle but when looking straight down on the scale it becomes more obvious) Could this mean the rear is now out of balance? Seeing as the right swingarm has remained secure during all this, and it's taken more of the load now?
  4. The markings on the swing arm are a loose guide only. Don't set your wheel alignment by them. Use a string-line or a straight edge. Once you know it is right, have a bit of a look at the calibration marks and get an idea how they look when the wheel is straight. Once you know that, you can set it (fairly close, in the ball park) by eye, using the calibration marks, but only when you know how they should look. Your bike may be straight when the right side is on the line and the left is 1mm ahead of it - I don't know.

    Also have a look (when you know it's right) at the clearance between the edge of the rear tyre and the swing arm. Some bikes have the tyre sit in the middle - some are much closer to one side than the other. Again, have a look and remember how it should be.

    It's also worth finding out if your bike is meant to be straight. Some are, some have an offset. ZX7Rs, for example, have a surprisingly large offset.

    Make sure the axle nut (castellated nut) is tight, then just ride it to the shop. This is their mistake, they can fix it.

    It wouldn't mean the wheel was out of balance, but it might mean the tension of the chain had moved the wheel a little forward on the left, making the chain a fraction looser and making the wheel alignment slightly wrong. This would be noticeable (if it was bad, a long way out) by the bike pulling to one side, or being much easier to turn to one side than the other. Having the rear wheel pointing a few mm to the right (say 20 ~ 30mm to the right of the centre of the front contact patch) would make the bike pull to the right enough to notice it.
    • Like Like x 1
  5. The chain is actually very loose, but there isn't any noticeable change in the alignment when I ride...I'll take it down there this week and we'll see what happens. Thanks for all your help KD
  6. hypothetically speaking, i'd bet that bike was serviced at Peter Stevens
  7. Lol, not quite. It's a Kawasaki dealership. If they don't own up and fix it then I'll name and shame but until then...
  8. (y) No worries.
  9. That seems like it could have very well been a dangerous situstion................
    AFTER they fix it, let us know who it is so I wont take my bike there!!
  10. Gave the dealership a call today and explained the situation, guy over the phone was very helpful, agreed that it was their bad, and is going to express post the parts to me so I can avoid potential disaster when I take it down to them to have a look at it (they're about 1.5hrs away). So far so good, and i'm not out of pocket either. But, as they say, time is money...
  11. BWHAhahahahahahahahah

    My first thoughts EXACTLY!
  12. !.5 hours away? Peter Stevens dandneong wouldnt take that long to ride would it?
  13. twisties on the way :D I bet
  14. whats wrong with peter stevens:-w
    they do have some good mechanics down at dandenong..........
    dont know bout the rest of the stores. but the parts interpreters are ace:D
  15. nones baggin you spennaroo, seems like the company you work for are gettin a pasting tho !!
  16. haha yeah i know.... im in the city this week too:p
    i can see why they get a bad rep. theres the guys i would gladly take my bike to in the workshop (usually these guys have graying hair - and this is down at dandenong) and some that i wouldn't let them touch it. (wont say who) but on the whole the younger guys seem to be a bit... well i dont want any comment to bite me in the bum. but lets just say the Harley's seem to get the best mechanics.
  17. Ok well an update. So far it's been a 2 week wait for these parts. They're apparently arriving tomorrow but you never know with these guys. By contrast, the day I found out about this (around a couple days before i started this thread) I took it to a nearby Kwaka dealership, ordered the parts on Friday, and they were in by Monday. Go figure.

    Yes that means that I'll be getting 2 sets of parts. I jumped the gun and ordered them straight away from this closer dealership, then realised it was the original dealer's fault (thanks kneedragon) so I got them to send me parts. Ill have to go back to the closer dealership and try and buy something else at the same value as the parts, or if not then just buy the parts themselves.

    Nearby delearship is Race Replica btw, big (y) to them.
  18. Nearby delearship is Race Replica btw, big (y) to them.[/QUOTE]

    have heard alot of good things about those guys..
  19. Why doesn't Race Replica do your servicing?.

    they are a good mob.
  20. kneedragon is dead on correct in his assessment. It happened to me once on the 650 after getting new tyres and the lock nuts weren't fastened. I lost both by the time I got home, luckily not the tension bolts and caps though. I was able to replace the lock nuts with some I had spare from a previous bike.

    I learned my lesson that day and it's worth sharing. Always check the nuts before leaving the workshop. Mine was at a highly regarded store and I have no hesitation in returning to that shop. It was a mistake and I understand that everyone f**ks up at least once in their lives. I rang the shop to let them know and they were mortified, apologised and thanked me for letting them know. I would use them again but I now never fail to check the work before riding away after someone else touches my bike. I've never had anyone take offence by my checking bolts and most appear very satisfied with compliments from customers when everything turns out to be well done.

    Constructive critisism and praise where it's due is as healthy for a bike mechanic as it is for the rest of us. Always check to be safe and say "thank you" to those who make it safe. :)