How to re-torque BBS split rim bolts.

[t-tony]

I'm getting my wheels refurbed this weekend coming and they are going to rebuild my wheels for me. So I need to know the torque figure for the 20 bolts in each wheel which the centre's to the barrels. If you have it please share.

I finished cleaning out the boot hole threads with a 7x1.0mm tap and blew them out with compressed air. I've got a bottle of stud lock to send with the bag of bolts along with a few spares courtesy of @Steve Medlock . Thanks Steve.

Tony.

 

[andyglym]

I'm getting my wheels refurbed this weekend coming and they are going to rebuild my wheels for me. So I need to know the torque figure for the 20 bolts in each wheel which the centre's to the barrels. If you have it please share.
View attachment 72498

I finished cleaning out the boot hole threads with a 7x1.0mm tap and blew them out with compressed air. I've got a bottle of stud lock to send with the bag of bolts along with a few spares courtesy of @Steve Medlock . Thanks Steve.
View attachment 72497 View attachment 72499 View attachment 72500

Tony.

Found this link mate, page one, 28lb feet torque?

http://www.bmw-driver.net/forum/showthread.php?t=24597#/topics/24597

 

[t-tony]

Cheers Andy.

Tony.

 

[andyglym]

Cheers Andy.

Tony.

 

[Jack Ratt]

What material are the bolts made from, are they steel or titanium ? If they are steel, do you know what grade they are ?

 

[Synclare]

As an aside Tony, if the centres and barrels as you call them are powder coated, does this present any need to re torque the bolts due to the powder coating squishing out/settling or whatever it's called when the two halves are compressed? I've a set of style 41 I think they are (split rim staggered) I want to refurb as an option for mine.

 

[hard top]

Cheers Andy.

You should already know that Big Ears, your the grease monkey on here ....

 

[t-tony]

As an aside Tony, if the centres and barrels as you call them are powder coated, does this present any need to re torque the bolts due to the powder coating squishing out/settling or whatever it's called when the two halves are compressed? I've a set of style 41 I think they are (split rim staggered) I want to refurb as an option for mine.

I'm told they mask of the mating faces Adrian so that there is no powder coat on those faces. Apparently they use a "silicon tape" which is not cheap?

Tony.

 

[t-tony]

What material are the bolts made from, are they steel or titanium ? If they are steel, do you know what grade they are ?

I believe they're Titanium Garry. That's why I was a bit worried about drilling the head off the only one which rounded when taking the wheels apart mate. We used a new Cobalt drill bit which did the job with ease.

Tony.

 

[t-tony]

You should already know that Big Ears, your the grease monkey on here ....

Something I've never done before Mike.

Tony.

 

[Synclare]

What stops corrosion setting in again if the mating faces are uncoated, I presume silicone tape is not left on permanently?

 

[t-tony]

The tape stops the coating fouling the threaded holes I assume, I will ask the man when I ring him to find out mate. I know a member on here said last year after having his done he sealed round all the joins with clear silicone. I cant remember his name now, he lives out your way, used to live in Lincoln. @Simon Blythe

Tony.

 

[Synclare]

Guess a water proof grease may work, corrosion often comes from inside out which is why I wondered. Are you having them bi colour again Tony?

 

[t-tony]

Yes mate, I'm having two colours. They're still original all silver as yet.

Tony.

 

[Jack Ratt]

I've had a look at some technical manuals and can't find anything that lists titanium bolts into aluminium. I've done a search and viewed various other forums and the consensus of opinion is 20-22NM with Loctite on the thread and do periodic checks afterwards.

BMW lists 7mm exhaust steel studs into engine block at 15-20NM so 20-22NM for titanium seems about right.

Titanium into titanium you would double that value, but as you're going into aluminium don't over do it.

Why not send an email to BBS, tell them you're doing a split rim restoration and ask them their recommendations

 

[mrscalex]

Found this link mate, page one, 28lb feet torque?

http://www.bmw-driver.net/forum/showthread.php?t=24597#/topics/24597

That sounds a bit high from memory. I've see the exact figure somewhere and I think it was closer to 20lb/ft. I'll see if I can find it because I'm finally going to get round to mine soon.

I wouldn't be so sure they'll cover up the holes/mating surfaces unless you ask.

 

[mrscalex]

http://www.bmw-driver.net/forum/showthread.php?t=24597

This says 28 lb/ft for this very wheel so maybe I'm talking cr*p. I'll carry on looking.

 

[mrscalex]

Well I've searched and checked around 20 different sources on the internet.

There are a lot of different views. 28lb/ft is mentioned a couple of times but the consensus seems to be 24/26. With some indeed saying 18/20.

I had it firmly in mind I was going to do 18 but can't find the source now. I'll probably go to 20 just for good measure but I'm not going as high as even 24/26.

 

[mrscalex]

One more thought...

This post is for a different wheel but someone emailed BBS and they were told 19lb/ft with blue Loctite. So perhaps the only definitive way is to email BBS for an answer.

http://dubberz.com/forum/rubberz/bbs-lm-torque-specs-from-bbs/

 

[5harp3y]

I'd email bbs personally