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Front end clonk

Discussion in 'Norton Motorcycles (Modern)' started by Fast Eddie, Apr 18, 2018.

  1. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    I don’t know, about RWU clearances. My forks are a 1/4 or so above the yokes, that’s as they left the factory So I assume it’s correct.

    But that 1/4 wasn’t the cause anyway, the cooler would still have been clouted as it was!
     
  2. TonyA

    TonyA VIP MEMBER

    Joined:
    Jan 16, 2015
    I wouldn't assume anything. I have seen those bikes with the fork tubes pushed flush and sticking up. If you run them pulled up you may need more pre load ?
     
  3. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    Fair point about assuming nothing!

    I don’t follow your logic about needing more preload if the forks have been pulled up though?
     
  4. Clive

    Clive VIP MEMBER

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    Jun 9, 2017
    Thanks for drawing this issue to my attention - I'm a terrible auto hypochondriac and when I heard the clonk a few months back I was sure I had damaged the forks/ clamps/ frame etc but on close inspection there is that tell-tale scuff on the mudguard. I was planning a modified mount but on reflection the modded hose approach is the best. I always wondered about the possibility of replacing the rubber 'ose with braided covered. Any thoughts?
     
  5. TonyA

    TonyA VIP MEMBER

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    Jan 16, 2015
    The fender is closer to the bike cooler.
     
  6. TonyA

    TonyA VIP MEMBER

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    Jan 16, 2015
    You have achieved a very nice angle now . Have you finally seen the one way valve in the return oil line ?
     
  7. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    Well yes ref pre load Tony, but pre load shouldn’t be used to try and limit overall fork travel. It would be a temporary ‘damage limitation’ exercise at best.

    But, the good news is the oil pipe fiddling solves the issue and only takes 10 minutes (beware the oil pipes are quite a tight fit on the cooler stubs though).

    I didn’t look for the none return valve! Will report back shortly!
     
  8. TonyA

    TonyA VIP MEMBER

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    Jan 16, 2015
    How are you reusing the hose clamps after shortening ?
     
  9. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    I fitted new ones Tony, the only way to remove these kind of ‘O’ clamps that I know of is to cut them off.

    I fitted new 15-18mm ones.

    A pair of sharp long handled pincers are required to cut them off. And an old pair of nicely blunt pincers are ideal to crimp the new ones.
     
    Last edited: Apr 19, 2018
  10. TonyA

    TonyA VIP MEMBER

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    Jan 16, 2015
    You don't like the screw clamps ? Did you find the one way valve or No ?
     
  11. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    There is NO none return valve in my return oil line either from engine banjo to cooler, or cooler to frame.

    Don’t know what this means to y’all, but there’s it is!

    I quite like these ‘O’ clamps and use them a lot. Plus, as they’re ‘stock’ on the 961, I kept with them.

    No reason not to use screw clamps to my knowledge.
     
  12. TonyA

    TonyA VIP MEMBER

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    Jan 16, 2015
    Latest service manual still shows the one way valve in the return line . Maybe Rob can tell us what they changed ? If they now manufacture the frame with the oil return above the level of oil in the tank they wouldn't need a non-return valve in the oil line. Could that be what Norton has done ? They should have done that from the beginning.


    Oil Pump Schematic Ref. No. #19

    Part Description

    Torque (Nm)
     

    Attached Files:

    Last edited: Apr 19, 2018
  13. MxMartin

    MxMartin

    Joined:
    Nov 13, 2017
    Much, much better and an easy peasy solution! How much oil did you lose in the process? If you didn't lose much oil then I guess the return line to the tank is above the tank upper level.
     
  14. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    Zero oil loss. And I mean ZERO, despite being ragged up and ready for it !
     
  15. MxMartin

    MxMartin

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    Nov 13, 2017
    Are you happy it doesn't need an additional bracket? As a devils advocate 'what if' the next pothole you hit is sufficient to use max fork travel and the 'inertia' also swings the cooler forwards on those rather flexible rubber mounts holding it on.
     
  16. MxMartin

    MxMartin

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    Nov 13, 2017
    ok wrong question, not loss, but how much came out with pipes detached :)
     
  17. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    If inertia swing the cooler forward it would still have to try very hard to touch the mudguard now.

    Even if it did, it would ‘touch’ rather than be clouted hard!

    No oil came out of the pipes at all. None. Zilch. Sans oil...
     
  18. MxMartin

    MxMartin

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    Nov 13, 2017
    Good, probably means the small quantity contained within has drained back down.
    ok, I'm heading to the garage now, going to try to ignore the blue skies and the thermometer on my way out...
     
  19. Fast Eddie

    Fast Eddie VIP MEMBER

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    Oct 4, 2013
    That manual appears to show ‘pre formed’ oil lines.

    These would be nice. But mine are simply lengths of tube cut off of a roll, as I imagine everyone else’s are.

    So this isn’t some big ‘design issue’ it’s an assembly quality issue. The guys cutting the oil hoses, and fitting them, have probably never been trained on the importance of them not being too long. All he has to do is cut them an inch too long and bingo, we have our problem!

    And, irrespective of the above (probable) training deficit, the QC processes are clearly not designed to confirm this either.

    In Norton’s defence, this kind of ‘non sexy’ and ‘old fashioned’ type of failure is all too common, even in very big corporations.

    The belief that technology will solve everything is WRONG and has a lot to answer for. Robust processes at the shop floor are still an absolute necessity.

    It’s a shame that Norton have repeatedly denied the offer of FREE help from highly experienced ex Toyota managers (no strings attached, they are simply Norton fans), as this is exactly the kind of thing that would have been nipped in the bud via use of some very simple Toyota methodology.

    Ah well...!
     
    Last edited: Apr 19, 2018
    richard-7 likes this.
  20. Rob Jameson - Norton UK

    Rob Jameson - Norton UK

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    Apr 9, 2018
    The return line check valve is a retrofit part for older bikes - which is why it is shown on the schematic.

    Two things happened on a frame revision - 1, we increased the size of the return feed inside the oil tank. 2, we reduced the level of the oil (which is why everyone changes their dipsticks). The purpose was to reduce the permissable amount of backfeed from the return, therefore reducing breathing on startup.
     
    Clive, richard-7 and 2cups like this.

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