Any ideas what caused this?

[ccr32]

Virtually brand new stainless Arrow exhaust link pipe on a Speed Triple - I've no idea what had done this.



Only thing I can think that it is either some road salt that I have missed when cleaning the bike which has then got to it, or it is ACF50 that was not rubbed in when I had applied it after the previous clean that has then got hot when I've started the bike up. Either way I can't seem to remove it.

Any ideas, and tips for bringing it back?

[Pothole]

The dark brown spots are also chemical reactions of the stainless steel surface, but instead of oxygen other materials are have a chemical reaction with the stainless steel surface. From the location and the pattern it is most likely junk on the road which mixed with rain and gets sprayed onto the exhaust. Examples I can think of are salt used to prevent icy roads in winter time, or minerals out of soil when driving on little roads also used by farmers’ tractors. These spots are more difficult to get off, but it is doable with determination and patience.

https://touron2wheels.wordpress.com/2013/05/26/cle...

[Freakuk]

I’d take a guess at brake fluid from your rear master cylinder, check there first is the reservoir full and sealed correctly?

The exhaust looks to be sat fairly close to the MC so heat from the exhaust could be boiling/expanding the fluid.

[Pothole]

This

[shielsy]

I have the same bike with the same exhaust and the same stains (but much worse). I think it's just general detritus that gets baked on.

[ccr32]

Thanks all. Will check around for brake fluid leakage and attack it with some Autosol first per the link, before resorting to the Harpic!

[Prof Prolapse]

Eh? It's normal.

My new bike had similar after I'd run it in...

[anonymous-user]

Yoshimura stain magic or pickling paste will get it off.

[RemaL]

Prof Prolapse said:

Eh? It's normal.

My new bike had similar after I'd run it in...

As above. looks like normal on a exhaust.
heat of exhaust. road grim, stuff picked up melts/sticks to exhaust

[bogie]

Looks normal and through normal use, over time the whole exhaust will end up that colour....then one bored winter morning you will decided to give it a good clean and be amazed how shiny it comes up, you forgot what "stainless" steel polished up looked like

...try the usual autosol, stain magic, all those kinds of metal polishes by hand. If that isnt enough then time for a machine polish....

[CarsOrBikes]

that's just due to splatter off the rear tyre, stainless doesn't mean it won't rust, it depends on what type of stainless it is. So if this is a monthly clean perhaps make it a weekly one, or just make sure you get to all areas if you think you missed it.

[Rubin215]

I use HG stainless steel cleaner which I bought in my local hardware shop for about £4; it's designed for hobs, splashbacks etc but it's fantastic on exhausts!

[ccr32]

Had a go at it today with some Autosol and a decent amount of elbow grease and it came up good and shiny, all these spots having been removed. Using the Autosol removed the discolouration too, which meant it looked a bit odd having not done the rest of the exhaust as well...


A quick 20 min ride out turned it back the same colour again...


Job done. Until next time.

[King Herald]

Depending on the quality of the stainless it could go a lovely golden colour, or it could past that to a dirty brown/purple rusty looking mess. Regular cleaning is the key.

Lots of people swear by Harpic bog cleaner for getting grungy stainless looking good, but I don’t think yours need that just yet.

[2wheelsjimmy]

Want to come and do mine?
I gave up a long time back.