Years experience or Bachelor's degree required

[Staffie]

Hello there

I need EXPERT advice.

I have a F800GSA and the little nuts on the brake rotor has "rusted".




Indicated in red and blue.

So after researching and finding the exact sizes/dimensions/width/length etc, I went and bought stainless-steel replacements.

After talking to some peeps I was advised that stainless-steel and aluminum will fuse under heat. Never knew that.

So here's my question...

1. The ones in yellow seem to be stainless-steel (from the factory it seems) or have they already been replaced? Reason I'm asking is I bought the bike second hand.
2. Can I replace the nuts in red and blue with stainless-steel and if so...
   1. do I use copperslip so that they don't fuse or
   2. do I use blue locktite so that they don't come loose?
3. my logic says the red ones on the rotor should be locktite and the blue ones on the fork should be copperslip...
4. Do they need to be torqued?
   1. Which ones and how much...?

Is there anyone with experience in metals or these kind of things that can explain or confirm.

I don't want to come off and crash because of a stupid mistake. I use my bike every day no matter what the weather and the brakes are kinda important...

Looking forward to replies...

 

[RobC]

Dare I say it? Coppaslip...

 

[luv2ride]

For expert advise and the correct parts - visit your dealer. This is not something where the possible saving of a Pooratech will benefit you

 

[EssBee]

Dare I say it? Coppaslip...

I can't live without the stuff. Anything Al gets it in my books.

 

[Malmoer]

"EXPERT ADVICE"
Bel BMW......................

My advies:
Geel is standard ja SS
Rooi het ek vervang met SS
Blou pyltjie het ek ook vervang met SS

Gebruik copperslip want SS en Alu like mekaar nie baie nie.

Boude op die roto kom nie maklik los nie maar voeg dalk "creep lines" by met tipex en check gereeld

My advies is gebaseer op my 800 wat ek 133000km al opgesit het....

use it , don't use it

 

[EssBee]

I put threadlock ( what most call 'loctite' but that's a brand name) on my disc rotor screws....your RED screws.

Regarding SS "fusing with Al " under heat....mmmm....is it any different to mild steel?

Oh...regarding copperslip...one of it's main attributes is heat resistance, besides just a lube/anti-seizing muti.

 

[ClimbingTurtle]

Work with me here...
The Red ones - are they holding the mounting plate to the hub, and the rotor disc bolts onto that?
If so, I would not use Stainless Bolts at all - stainless does not torque well - I have snapped Stainless off with not too much effort at all.... And if so, I would consider these Safety Critical items, I would go with Standard Bolts from BMW and not mess around. - same with the blue bolts - safety critical - dont mess around
However, you can get all of the standard bolts zinc coated for very little cost - this would be my route!

 

[Cage]

Work with me here...
The Red ones - are they holding the mounting plate to the hub, and the rotor disc bolts onto that?
If so, I would not use Stainless Bolts at all - stainless does not torque well - I have snapped Stainless off with not too much effort at all.... And if so, I would consider these Safety Critical items, I would go with Standard Bolts from BMW and not mess around. - same with the blue bolts - safety critical - dont mess around
However, you can get all of the standard bolts zinc coated for very little cost - this would be my route!

Correct = ss does not have the torque strenght of carbon steel bolts. SS has low carbon content, which cannot be hardened. I would stick clear of them for the application that you're considering......

 

[Cage]

If you don't want the cs bolts to rust, get them plated properly with something.

 

[EssBee]

Boude op die roto kom nie maklik los nie maar voeg dalk "creep lines" by met tipex en check gereeld

Goeie plan. Die torque op daai skroefies is baie laag @ 8Nm.

 

[Cage]

I put threadlock ( what most call 'loctite' but that's a brand name) on my disc rotor screws....your RED screws.

Regarding SS "fusing with Al " under heat....mmmm....is it any different to mild steel?

Oh...regarding copperslip...one of it's main attributes is heat resistance, besides just a lube/anti-seizing muti.

The "fusing" is actually referring to galvanic corrosion
Galvanic corrosion is an electrochemical process in which one metal corrodes preferentially when it is in electrical contact with another,

 

[Welsh]

I put threadlock ( what most call 'loctite' but that's a brand name) on my disc rotor screws....your RED screws.

Regarding SS "fusing with Al " under heat....mmmm....is it any different to mild steel?

Oh...regarding copperslip...one of it's main attributes is heat resistance, besides just a lube/anti-seizing muti.

yes stainless to stainless and stainless to aluminium is a different chemical reation to Mild Steel and that zinc plating makes a difference as well.

Stuff Coppa slip, Wurth do an Aluminium anti sieze, MUCH BETTER.

 

[Welsh]

Correct = ss does not have the torque strenght of carbon steel bolts. SS has low carbon content, which cannot be hardened. I would stick clear of them for the application that you're considering......

Whilst I agree mostly, both Carbon Steel and Stainless have Multiple grades of strength, your statement is a bit broad brush.

 

[Welsh]

Hello there

I need EXPERT advice.

I have a F800GSA and the little nuts on the brake rotor has "rusted".


View attachment 824098

Indicated in red and blue.

So after researching and finding the exact sizes/dimensions/width/length etc, I went and bought stainless-steel replacements.

After talking to some peeps I was advised that stainless-steel and aluminum will fuse under heat. Never knew that.

So here's my question...

1. The ones in yellow seem to be stainless-steel (from the factory it seems) or have they already been replaced? Reason I'm asking is I bought the bike second hand.
2. Can I replace the nuts in red and bluewith stainless-steel and if so...
   1. do I use copperslip so that they don't fuse or
   2. do I use blue locktite so that they don't come loose?
3. my logic says the red ones on the rotor should be locktite and the blue ones on the fork should be copperslip...
4. Do they need to be torqued?
   1. Which ones and how much...?

Is there anyone with experience in metals or these kind of things that can explain or confirm.

I don't want to come off and crash because of a stupid mistake. I use my bike every day no matter what the weather and the brakes are kinda important...

Looking forward to replies...

Firstly, I have the qualification and the experience.

Secondly, they are not nuts, they are Bolts and Machine Screws.

Then troll the WEB and even here you may find a manual which will tell you the torques and what needs Loctite AND WHICH GRADE, Loctite also has different grades.

Then the Blue bolts not high torque around 22Nm so stainless OK but get the Wurth anti sieze.

The Reds, not sure if they fix both the ABS ring and the disc carrier, if the disc carrier establish exactly what and maybe go OEM.

Heat has nothing to do with the Aluminium / Stainless reaction, it is Chemistry, get the Wurth.

 

[Bordercollie]

If you really want to go for stainless steel bolts, go AN.

They have have a shear strength, high bendability and designed for an alum environment.

Wurth products is worth the money.

 

[2StrokeDan]

Firstly, I have the qualification and the experience.

Secondly, they are not nuts, they are Bolts and Machine Screws.

Then troll the WEB and even here you may find a manual which will tell you the torques and what needs Loctite AND WHICH GRADE, Loctite also has different grades.

Then the Blue bolts not high torque around 22Nm so stainless OK but get the Wurth anti sieze.

The Reds, not sure if they fix both the ABS ring and the disc carrier, if the disc carrier establish exactly what and maybe go OEM.

Heat has nothing to do with the Aluminium / Stainless reaction, it is Chemistry, get the Wurth.

Anyone that has ever struggled with a KTM stainless steel swingarm chain adjuster bolt screwed into alloy , will know that heat plays no role.

Stainless does "work-harden" when drilled or machined though.

 

[Welsh]

Anyone that has ever struggled with a KTM stainless steel swingarm chain adjuster bolt screwed into alloy , will know that heat plays no role.

Stainless does "work-harden" when drilled or machined though.

Yes, it work hardens, its a bitch to drill when it does that.

The other thing many people do not know, is that you must never assemble a 304 stainless bolt with a 304 nut, same with 316 etc, a 304 bolt should get a 316 nut or vice versa.

If the same grade they "gall" or cold weld together, the way we used to avoid this if it was essential that they were the same grade, was to give the Bolt a 5 micron flash coating of electroless Nickel to form a barrier coat.

 

[Cracker]

Galling ..................l!!!! ........................... now there's a coincidence.

Just yesterday I was trying to repair some SS door hinges on a sub-station that had blown open in the wind.
10 mm SS bolts and nuts, screwed through 2 inches of fibreglass and SS plate. They came apart easily enough but when I put them back in they seized. Badly enough that I can't remove them either.
I did wonder why, assumed it was shit Brit quality, I've never seen that before. They were clean, no rust, no wear, used only once. And now they're in an area, locked fast, and I can't get a grinder in to remove. A problem for another day.

But, now I know ............... galling makes sense ........................ thanks

 

[EssBee]

@Welsh ah yes aluminium anti-seize....I've forgotten it even existed.

The Reds, not sure if they fix both the ABS ring and the disc carrier, if the disc carrier establish exactly what and maybe go OEM.

Yes, the Reds hold the disc rotor bosses onto the wheel hub....left side the ABS ring too. This is where I used SS and is pretty much the trigger to this whole line of thought. 8Nm is the std torque setting for these.

I certainly don't dispute all the remarks regarding having all these bolts re-electro-plated, if it's convenient/practical.

 

[Welsh]

@Welsh ah yes aluminium anti-seize....I've forgotten it even existed.


Yes, the Reds hold the disc rotor bosses onto the wheel hub....left side the ABS ring too. This is where I used SS and is pretty much the trigger to this whole line of thought. 8Nm is the std torque setting for these.

I certainly don't dispute all the remarks regarding having all these bolts re-electro-plated, if it's convenient/practical.

It’s this stuff Essbee