Gearbox Sprocket Torque

[dunx675 2]

Hi

 

I need to replace my NC750SD chain and sprockets. Does anyone know of any supplier of kits, and also, what is the gearbox sprocket nut torque (and for that matter, the torque for the wheel sprocket too).

 

Thanks

 

Dunx

Edited November 1, 2016 by dunx675

[wendeg 95]

Drive sprocket bolt torque: 54Nm

Driven sprocket nut torque: 108Nm

 

These are the values given by Honda in their workshop manual for the NC750X/XA/XD/S/SA/SD for the year 2016... might be the same as the pre-2016 models.

 

As regards sprockets suppliers... I would stick with the original Honda parts to avoid wear issues on output shaft splines. Original sprocket material is supposedly softer than output shaft material. With my previous bike, Transalp, there were horror stories of sprocket wearing the splines. To my knowledge, this was due to using pattern sprockets (especially drive sprocket).

 

As for the chain, I think it would be cheaper if you use the DID or RK oem chain than the same chains but paying more just for the HONDA print on the box. The workshop manual specifies these chains:

 

DID: DID520V0

RK: RK520KHO

 

Personally I would go for the DID simply because I have had only DIDs on my bikes and i've never had anything bad to say on them. That's not to say that RK are not good... they might even be better than the DIDs for all I know.

 

I would also buy the 'softest' chain available rather than High Strength or Super High Strength chains. I would rather pay to replace a chain than pay to replace an output shaft. The only upgrade I would make is the type of rubber ring on the links... I would go for an X-ring rather than an O-ring

 

The number of links specified for the 2016 models are these: for the MT 114 links, for the DCT 112 links (now that's strange).

 

If you want anymore torque values just ask.

 

[Derek_Mac 1,404]

26 minutes ago, wendeg said:

>snip<

 

The number of links specified for the 2016 models are these: for the MT 114 links, for the DCT 112 links (now that's strange).

 

>snip<

 

 

Lawrence, how is that strange?

 The DCT bike and the manual bike have differing sprocket sizes hence the different length of chains.

 

Edit:  The torque for the rear axle nut should be 98 N.m in addition to the other values that you gave.

 

Edited November 5, 2016 by Derek_Mac
adding information

[wendeg 95]

Thought the DCT and manual have the same sprocket size... was wrong

[dunx675 2]

Thank you very much.

[Guest sykospain]

Having had nightmares with anbormal wear in BMW primary-drive splines that mate with the friction plate in the ancient dry single plate clutch design which they used from inception in the fifties right up until 2012, effectively a Mini Minor clutch arranged back-to-front.....

......I'm surprised to see mentions of possible wear in Honda drive splines if the wrong grade of drive spocket material is used.

I wonder how many members have replaced sprocket and chain sets with 3rd party items, not knowing whether the chosen drive sprocket ( front )  is sacrificial with respect to the engine's internal drive splines ?

And I wonder what's the cost of a new spline-shaft, including stripping the motor in order to fit it ?

Edited November 8, 2016 by sykospain

[embee 7,288]

The NC sprocket is a slip fit on the gearbox output shaft splines and is not clamped by the bolt/washer, it "floats".

 

One of the things I did very early on when I got my NC was remove it and apply Moly60 to the splines. I can't say I really like this arrangement, but I'm sure it will survive fine (from Honda's experience), but I do feel it will benefit from some solid lubricant to prevent fretting/galling wear issues. Hopefully as others say, the shaft is more wear resistant than the sprocket.

 

Incidentally, the Moly60 paste I use is the Honda stuff. I got it from https://motocrossworld.com/index.php/ but they don't seem to list it now, however this is an equivalent product http://www.draketooling.co.uk/Products/maintenance_workshop_anti-sieze/AS60 . Note it is not the same as regular moly grease, this is 60% moly for splines etc. I use it on the drive splines on my Deauville and BMW.

[Guest Mac750]

I used to grease the rear splines on my K series BMW's every tyre change (mono link) and every two years on the other end this meant lifting the whole bike high in the air to do the job and was a PITA. Bought a shaft drive Honda and greased the shaft splines once with 6%white moly grease and after inspection a few times never bothered after that as they never wore out. 3x Honda PC 800.

Honda recommended 6% white Moly Grease but my supplier informs me you cannot buy it at 6% any longer as I understand it is a carcinogen.

So I have been using car type UJ or drive shaft grease which is less harmful apparently. 

Edited November 17, 2016 by Mac750
Grammar

[embee 7,288]

60% MoS2 is what is recommended, that's what the Honda Moly60 was. As per the link, equivalent stuff is still available from some merchants.

I've seen it written that Honda M-77 paste has superceded the M-60, but I can only find that at ridiculous prices. As and when I need more I'll get the stuff from Draketooling.

Carcinogenic? The H&S data sheets I can find don't seem to think so, unless there's other stuff in it besides MoS2

http://www.molybdenumconsortium.org/assets/files/IMOA MoS2 Hazard Assessment May10Final2.pdf

Edited November 17, 2016 by embee