Resurfacing discs

[hobbsy84]

Just looking into the braking parts of the '81 Standard I'm rebuilding, and the next item on the list is the brake rotors. Poor things seen better days, to put it one way. They've seen a lot of weather, and not much use, so the rust has basically taken over. Due to this, there's a fair amount of pitting on them.
What I'm wondering is, has anyone had brake discs for these bikes re-surfaced/ground down, and would there be limits to how much could be ground off?

[egsols]

See this

http://www.xs11.com/forum/showthread.php?s=&threadid=12845&highlight=rotor

[rbmgf7]

i did this

http://s231.photobucket.com/albums/ee149/gearbot/?action=view&current=MOV00836.flv\

which came out to this

[trbig]

rbmgf7,

As that seemed to work for removing rust off of a metal surface, I would NEVER recommend anyone ever doing that to brake discs. They need to be turned on a lathe to remain true. I can't even imagine what those are like under heavy braking.

I'm really not trying to be a jerk or cut you down.. there is just a reason why people don't take their front discs off their car, set them in their laps, and start grinding the grooves off of them.

That being said, I have heard that there are problems with turning the discs and having them warp afterwards. What you might try is turning them, then drilling them to help dissipate the heat to help with warpage.

OR... looking on Ebay for some good used ones would probably be the cheapest route if that's what you're looking for.


Tod

[hobbsy84]

Hmm, from the sounds of this, it sounds like it's time to go annoy the local wrecking yards again
Thanks for the input though, guys.

[Geezer]

They can be resurface but you need to find a machine shop that surface grinds rather than lathe turns them. Stainless steel doesn't cut well on a lathe like iron rotors used on cars and only a few bikes.

The iron rotors on my old Guzzi worked fantastic but looked like crap if the bike sat more than 24 hours. I tried baking on black paint to cover the areas where the pads didn't ride and that only lasted a month...

Geezer

[XSPastor]

FWIW - There's a guy on ebay the will grind them for you for 50 bucks each. ebay item number 300242345391.

[andreashweiss]

And i can send you a left right front match pair of non slotted rotors with bolts and clips, awesome shape, last for yrs not grooved or warped, $100 includes ship to australia.andreas

[hobbsy84]

You've got a PM coming your way, Andreas.

[GNEPIG]

XS1100 BRAKE DISC ROTOR MACHINE:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300242345391

Hey, that guy is back. Looks like he does good work, but his prices have gone up almost 20 bucks since I last seen this auction. Demand must be up.


Quote:
The iron rotors on my old Guzzi worked fantastic but looked like crap if the bike sat more than 24 hours. I tried baking on black paint to cover the areas where the pads didn't ride and that only lasted a month...



Yeah, the same with the front rotor on my old 73 Norton.

[HobbyMan]

So we can't turn these on lathes?

[LoserShoes]

Originally posted by HobbyMan
So we can't turn these on lathes?

It can be done, but requires the correct grind on the cutting tool and a spray mist coolant. Not the kind of skills your going to find at an automotive machine shop. And in todays CNC world those skills a getting increasingly rare.

In the '70s one of the Cycle mags had an article about turning stainless rotors in a lathe.

Steve