has anyone else seen these brake disc before? they look like they have been treated black or purple colored.

i need a new back disc and was thinking about these, but was wondering if they stay colored for the entire life of the disc, or if they rub off after a few weeks.

i suppose if they were heat treated the color would last fairly long, but if they were dyed wouldnt last very long.

anyone know how they do this?

Pictures would help us!

However, it could be that they made the discs out of Titanium. Titanium will discolour like that if exposed to heat; there's nothing wrong with the metal. However, you're looking at some 250 USD per rotor! There's a chance that what you saw was real titanium, but if saw in Thailand I'd be more inclined to think it's fake (like all those 'brembo' brakes on the bikes). Here's a picture of some heat treated titanium ore:

And you've probably seen titanium exhausts:

i saw these disc in a thai motorcycle magazine, so no titanium here!

other than these disc ive seen car brake rotors in some weird colors like purple, blue, pink...so am just wondering....does the color last?...i have a hunting knife that has similiar heat treated colors applied to it.

maybe i'll scan a pic if i stop being too lazy to hook the scanner up.

i saw these disc in a thai motorcycle magazine, so no titanium here!

other than these disc ive seen car brake rotors in some weird colors like purple, blue, pink...so am just wondering....does the color last?...i have a hunting knife that has similiar heat treated colors applied to it.

maybe i'll scan a pic if i stop being too lazy to hook the scanner up.

I am not sure what you're talking about; but if they're aluminium they could be anodised. That will of course quickly wear off, assuming you're talking about being coloured all the way from the centre bolts to the edge of the disc....however that would be extremely foolish since the coating would wear off extremely quickly and actually operate as a lubricant until it was gone! Quite a few of the fancy-schamancy brake discs have a centre section that's anodised though....

I seem to remember it was possible to heat treat some metal to get that titanium rainbow look (heat it then anneal it with oil) that wasnt a surface only thing, went right through..