Author Rear Sprocket nut torque  (Read 4267 times)

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  • Offline FireBladerDk   dk

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    Offline FireBladerDk

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    Re: Rear Sprocket nut torque
    Reply #10 on: 02 January, 2016, 04:24:34 pm
    02 January, 2016, 04:24:34 pm
    *Originally Posted by Robo [+]
    A cheap or damaged torque wrench can do more damage than not using one.

     :028:

    Ha ha Robo - that's right.

  • Offline jm2   england

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    Re: Rear Sprocket nut torque
    Reply #11 on: 03 January, 2016, 12:04:49 am
    03 January, 2016, 12:04:49 am
     :435: Who's suggesting my torque wrenches are cheap or damaged ?

  • Offline YDraig

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    Offline YDraig

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    Re: Rear Sprocket nut torque
    Reply #12 on: 12 February, 2024, 01:07:09 pm
    12 February, 2024, 01:07:09 pm
    I know this is an old thread. 
    I'm in the process of replacing chain and sprockets on mine and thought 'why not do it right and lookup the torque specs?'  I've got the tools may as well use them properly.  I found that 108NM spec it's double the single (albeit smaller thread) bolt holding the front sprocket and there's more of them them so I thought I'd check on here.  I too was concerned on the studs tearing out of the alloy carrier myself.  I'm not sure I'd copaslip them though, seems more apt to use threadlock (blue of course) as there are no locking washers or tabs that I've usually found on sprocket bolts. Threadlock will also help prevent corrosion and lubricate the threads during assembly.  And with threadlock I think it'd be safer when de-rating the torque setting by 20%.
    There were bl**de tight and I'm glad I decide to crack them off with the wheel in the bike,  Sat backwards with left foot on the rear brake and a 2 foot breaker bar with impact socket on each nut, and the still took a good pull on the bar.  I know I would have struggled without a bolted down vice and bench If i'd removed the wheel and sprocket carrier first.

  • Offline FireBladerDk   dk

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    Re: Rear Sprocket nut torque
    Reply #13 on: 12 February, 2024, 04:40:38 pm
    12 February, 2024, 04:40:38 pm
    Hi YDraig,

    You are right that the specifed torque for the rear wheel sprocket nuts is quite high at 108 Nm.

    In section 9.0 of this DIY article you can read my thoughts on the subject, from when I replaced the rear sprocket in 2011 on my CBF1000A07:

    http://www.fireblader.dk/i_files/cbf1000chain/mc033.htm

    The load on the sprocket via the chain from the engine is very high and includes vibrations as well. So torque must be high. I have little or no knowledge of how thread locking can - or maybe can not - add to the effective holding force on the sprocket.

    But as Honda decided to specify 108 Nm dry torque with no thread lock, I would myself be hessitant to go much lower than specied, even with thread lock.

    Regards Fred  :041:

  • Offline Art   england

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    Re: Rear Sprocket nut torque
    Reply #14 on: 12 February, 2024, 04:41:55 pm
    12 February, 2024, 04:41:55 pm
    Just one of the excellent articles by FireBladerDk

    The manual is correct rear sprocket nuts 108 Nm, front sprocket bolt 54 Nm, no need for a threadlocker.

    I've replaced the CBF1000 drive chain and sprockets twice now, never used and no need for a threadlocker. Even using a medium strength threadlocker such as Loctite 243 will add to the effort required to remove the nuts and bolt when the time comes. I clean the threads and fit both the bolt and nuts dry, remember to give the gearbox output shaft a coat of lithium grease before fitting the front sprocket.

    Here in the UK I source drive chain and sprocket kits from Hunters of Newcastle for best value.
    Last Edit: 12 February, 2024, 04:48:05 pm by Art

  • Offline YDraig

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    Offline YDraig

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    Re: Rear Sprocket nut torque
    Reply #15 on: 19 February, 2024, 11:41:59 am
    19 February, 2024, 11:41:59 am
    Just for completeness if anyone else goes through this thread:
    With clean and dry threads I stuck with the 108NM torque setting, there were no signs of any issues going this tight.  Thing is I've known the manual (manufacturers workshop) be wrong before on other bikes (wrecked one kawasaki head with wrong cam-chain tension procedure from following the manual many years ago)...

  • Offline raYzerman   ca

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    Offline raYzerman

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    Re: Rear Sprocket nut torque
    Reply #16 on: 19 February, 2024, 10:41:53 pm
    19 February, 2024, 10:41:53 pm
    In my opinion, this is a classic case of over-engineering.  The studs are heftier than most other similarly powered bikes' sprocket bolts.  Their torques are much lower, so I propose you go 108NM max with a dry thread.  In addition, the nuts are FujiLoc (as is the rear axle nut), with the metal piece that indeed is your thread locker.  They won't come loose.  Nor is there really any significant side load on the sprocket.

    As for lubricated threads, consider Loctite a lubricant if you used a liquid.  When anti-seize or "copper grease" is used, the torque should be reduced 30% and you will achieve the same clamp load.  If you lubed with engine oil, you'd reduce it even further. 

    I'm just swapping out my rear sprocket today to change the gearing... I'm going to use a common sense torque of ~80Nm.  A short list of a few bikes and their torques......

    VFR800 - 34Nm (25 ft. lbs.), surprisingly low one could say
    Versys 1000 - 60 (44)
    Tracer GT - 80 (59)
    DL1050 - 60 (44)

     



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