Rear sprocket nuts

S1000RR  FORUM

Help Support S1000RR FORUM:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

RRoss

Well-known member
Joined
Apr 30, 2016
Messages
372
Reaction score
0
Location
Perth
Hi,am changing rear sprocket and chain and have downloaded the bmw service manual and looking at it,the rear sprocket nuts have to be tightened to 110Nm and replaced. My questions are can someone confirm the torque value and is it really necessary to replace the nuts?
 
That seems high? I just changed mine to ti as the bm ones got corroded over winter . Pretty sure i didnt go that high

Sent from my SM-G920F using Tapatalk
 
That's what I thought. Looking in the service manual all I can see is "chain sprocket to sprocket carrier" 110nm. It mentions tightening them diagonally and replacing as they have a mechanical lock feature. Just taken original ones off and did so with relative ease using a spanner.


Sent from my iPhone using Tapatalk
 
Just been looking and almost all posts are saying 110 nm. I think i better go out and give mine another 1/2 a turn 😂😂😂

Sent from my SM-G920F using Tapatalk
 
Its defo 110nm and to replace the nuts according to the BMW service data. Plus the tightening sequence is diagonal.

My understanding of the mechanical lock feature of the nuts is that they will gradually lose the mechanical lock strength after x amount of uses which can result in incorrect tightening, I believe BMW say they need changing every time to cover their arses. I would be changing them when I replace my rear sprocket for piece of mind.
 
Rear Sprocket

I had to check this with BMW before I obtained a Service & Repair Manual. They stated that the torque setting for the rear sprocket to carrier on the HP Forged Wheels was 70 Nm then an additional 90? degree turn.
 
The torque rating for Titanium will be different too, much the same as any torque rating will change if you add any form of grease or threadlock to a bolt that doesn't normally have it regardless of what the manual states.

Seen it plenty of times where people have changed bolts and not taking into account what the bolts are made of and then over tightened them by using the manufacturers torque setting on bolts that have a lower tensile rating ;)
 
Chain sprocket to chain-sprocket carrier
M12 x 1.5, counter-hold the screws and turn the nuts. Replace screws and nuts
Tightening torque, 70 Nm
Additional angle of rotation, 90?

Thats the spec for forged wheels - thanks for pointing that out Ryan, had never considered they would be different.
 
They are throw away nuts but I just lock tighter mine , also bm dealer would not give me the settings
 
Cheers folks,I'm gonna re-use the original nuts,tighten them correctly and keep an eye on them as A,I'm likely to replace them with titanium sooner or later and B,I'm a tight Scotsman lol
 
Think i paid 20 quid for my ti bolts, even a tight scotsman can see thats a good deal 😂😂😂
9ebbf8cff6ef60b5e283be0656abd38e.jpg


Sent from my SM-G920F using Tapatalk
 
Not that you can see them in that pic 😂😂😋

Sent from my SM-G920F using Tapatalk
 
That's a really good price,what's the quality like?


Sent from my iPhone using Tapatalk
 
Normally use Probolt as the finish is good,but these look just as good and cheaper.


Sent from my iPhone using Tapatalk
 
Yep all good. I got speocket nuts, rear sprocket nut, pinch bolts and caliper bolts from them

Sent from my SM-G920F using Tapatalk
 

Latest posts

Back
Top