Bead blast front rotor/disc?

gtsun · Oct 22, 2009

My stock front rotor was rusty & porely painted so when I rebuilt my hubs recently I bead blasted the disc/rotor as well as the rear hub brake surface. Now I'm wondering if I was not supposed to blast the front disc surface. It was glazzed but not out of round/ true at all. Just a thought. Are they plated with chrome or some other thing and not to be bead blasted?

swooshdave · Oct 22, 2009

THey were originally plated but a common mod was to skim the chrome off (on a lathe). If it were me I'd bead blast the rotor (to remove rust), paint the non-braking areas and then have the rotor surfaces skimmed to provide the ideal braking.

Flo · Oct 22, 2009

I have never heard of them being plated, Harleys & I think Triumphs were.
O/k to bead blast, the braking area will soon shine up in use. Presuming glass beads, around no. 13?

batrider · Oct 22, 2009

My 1972 disc was chrome plated and worked very well at the time.

Rather than painting the unswept areas of the disc, you can have Bruce Chessell nickel plate the entire thing and after a while the nickel gets abraded off the swept area leaving the rest of the disc with a nice not-too-shiny finish - even in the holes... looks great and so far has held up well (3rd season).

GRM 450 · Oct 22, 2009

It's not a good idea to paint the flat mounting surface, where the disc mounts to the hub.
There's always the chance the paint will be slightly thicker at one point and this will not let the disc sit flat.
Then your disc won't run true, (give the same feel as a warped disc)

Mk3 discs were chromed, another questionable idea.

gtsun · Oct 23, 2009

Thanks for the info guys. Should be rolling again soon.

Rich_j · Oct 23, 2009

batrider said:
My 1972 disc was chrome plated and worked very well at the time.

Rather than painting the unswept areas of the disc, you can have Bruce Chessell nickel plate the entire thing and after a while the nickel gets abraded off the swept area leaving the rest of the disc with a nice not-too-shiny finish - even in the holes... looks great and so far has held up well (3rd season).

I tried something similar when I painted mine. I thought the pads would just take off any overspray.
Bit embarrassing when I put the brakes on in anger for the first time, tried to ride off and found the brakes locked with pads glued to the disc.

Flo · Oct 23, 2009

Well, I'll be blowed. Never knew they were plated.