Rust on front discs - cure?

General discussion of the BMW R1200RT/R1250RT
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Tony Fyson
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Rust on front discs - cure?

Post by Tony Fyson »

The front discs on my RT1250 are showing signs of rust near the mounting buttons.  The bike is less than a year old.
What is the best way of removing this rust, and preventing re-occurrence?
Thanks.
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David.
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Re: Rust on front discs - cure?

Post by David. »

Depending on the severity of the rust, Autosol metal polish applied with a cloth, old toothbrush or 0000 grade steel wool should do the trick.

Autosol itself claims to "protect against corrosion and tarnishing".

It's not a bad idea to use some brake cleaner afterwards to ensure the disc friction area has not become contaminated. Perhaps even removing the pads/caliper beforehand too.

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Last edited by David. on Wed Apr 15, 2020 11:00 am, edited 1 time in total.
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Beagle
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Re: Rust on front discs - cure?

Post by Beagle »

As the discs are stainless it is probably rust from the bobbins bleeding onto the surrounding disc.
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David.
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Re: Rust on front discs - cure?

Post by David. »

Rust on bobbin, https://advrider.com/f/threads/brake-di ... re.802898/

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JVB is known as a bit of a BMW Guru, "Stainless steel rotors still rust if parked outside", and this one was.

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Tony Fyson
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Re: Rust on front discs - cure?

Post by Tony Fyson »

The rust on my discs is not caused by the bobbins, and looks like a less severe version of that shown in the last photograph.
If I clean the rust off, surely it will come back again, unless some sort of protective coating is applied. Clear nail varnish perhaps?
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David.
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Re: Rust on front discs - cure?

Post by David. »

Tony Fyson wrote:If I clean the rust off, surely it will come back again, unless some sort of protective coating is applied. Clear nail varnish perhaps?
Good idea, I have read elsewhere of folks cleaning up the disc bolts, then applying a clear lacquer of some description to maintain the appearance.
Little-Brit
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Re: Rust on front discs - cure?

Post by Little-Brit »

There are dozens, possibly hundreds, of different grades of stainless steel. Some are very "stainless" some less so. They can have markedly different mechanical properties but none of them are going to corrode away! Some may need a bit more love and attention to stay looking pristine but they aren't going to "fail" on you. Trust the engineers that specified the grade, they will be far more aware of the advantages and shortcomings of their choices than the vast majority of punters. I certainly don't worry about surface corrosion on stainless steel components.
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David.
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Re: Rust on front discs - cure?

Post by David. »

More rusty stainless discs, ride all year and they won't go rusty!

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Re: Rust on front discs - cure?

Post by simbo »

David. wrote: More rusty stainless discs, ride all year and they won't go rusty!

Image

What do you mean? Are you saying they have mild surface rust due to riding through winter? Or they have mild surface rust from being laid up over winter?
The GS 'is' the better bike :-)
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David.
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Re: Rust on front discs - cure?

Post by David. »

The latter.
Last edited by David. on Sun Apr 26, 2020 8:46 pm, edited 1 time in total.
Iscadean
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Re: Rust on front discs - cure?

Post by Iscadean »

You can get titanium disc buttons on eBay. Bit expensive though.
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Re: Rust on front discs - cure?

Post by simbo »

Harpic power plus max 10 will clean the rust off.
The GS 'is' the better bike :-)
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