are rotors turnable? the bike shop says NO!?

[fredintoon]

Yes but no.

Hi Midnight,
betcha your local shop only has a brake lathe, (a specialised machine tool for resurfacing cast iron automotive drums & disks). No way can an XS11 disk be turned on one of those. Firstly,the cutting tool is purpose-ground to cut cast iron and won't work well on the tough as a bastard stainless steel the XS disks are made of.
Secondly, the dished XS disk won't fit on the machine. That same dished shape stops the disk being refinished on a Blanchard grinder except on one side.
OK then; a custom machine shop could set the disk up with a backing plate to kill the vibration that could cause chatter marks and experiment with tungsten carbide tooling feeds, speeds & cutting angles to eliminate surface tearing. Most likely they'd want a signed waiver if they wrecked the disk and ask more than a C-note just to try.
Best you look for a used replacement.
Fred Hill, S'toon.

[TomB]

betcha your local shop only has a brake lathe, (a specialised machine tool for resurfacing cast iron automotive drums & disks).

Ahh! Thanks Fred

[midnight1980]

Re: Yes but no.

Originally posted by fredintoon
Hi Midnight,
.
Best you look for a used replacement.
Fred Hill, S'toon.

nah i just put a metal disk sander on a drill and put the rotor in a vice and smooth out the groves today in the shed

[HobbyMan]

[fredintoon]

That'd work too

Hi Midnight,
Yeah, a man's gotta do what a man's gotta do, right?
I took an angle-grinder & sanding disc to the rear brake disk of a Honda 750 my son bought against my advice. Stupid PO had let the rear pads wear down to the metal and the disk had gobs of brakepad backing plate friction-welded to it. Cleaned up OK though. (You could still just about see where the final drive sprocket's teeth used to be. That's not brake related although it was another reason that he shouldn't have bought the thing in the first place).
Fred Hill, S'toon.

[midnight1980]

Re: That'd work too

Originally posted by fredintoon
Hi Midnight,
Yeah, a man's gotta do what a man's gotta do, right?

yeap! theres a time to just too get basic.

[nate]

So if i read correctly.The grooves in my rotors don't matter,and i can use an angle grinder to knock the weld on brake pad particles?

[Douglas Money]

As far as the grooves yes, they don't matter unless they are too deep "insert your your definition of too deep here". I don't know about the angle grinder.

[TopCatGr58]

Originally posted by nate
So if i read correctly.The grooves in my rotors don't matter,and i can use an angle grinder to knock the weld on brake pad particles?

Nate, an angle grinder is probably a bit too strong. I used a wire brush on a drill to remove the accumulated rust from mine, it'll remove the brake pad material but won't damage the underlying brake rotor.....IMHO! YMMV!
T.C.

[fredintoon]

Gently with the angle grinder

Hi Nate/TC,
I used a sanding disc with a rubber backing wheel on a 4-1/2" angle grinder. That set-up was sharp enough to remove friction-welded gobs of steel while being flexible enough to not dig into the brake rotor. I'd say a rigid grinding wheel would be far more likely to trash the rotor than to salvage it. Lucky for me, the inner pad still had some friction material left on it so the brake rotor's inner face was still OK, otherwise I would have had to remove the rotor rather than fix it in-situ. BTW, XS brake rotors are made of some kinda stainless steel, what would make one rust? I have seen the cast-iron rotors on a Guzzi rust over a lunch stop on a rainy day but when I screamed & pointed the owner said not to worry, it'd polish off the first time he hit the brakes.
Fred Hill, S'toon.