I know cutting rotors isn’t really done much anymore. Usually the labor to do it exceeds the cost of a decent replacement.

25 years ago I used to be a dealer flat rate tech at Ford & cutting rotors was the norm. I was around when we first started with on the car rotor cutting lathes. Ford sent them to fix the big Broncos & F150s brake pulsation woes.

I’m wondering now - does anyone cut rotors? I’m looking for someone to cut a set of expensive (~$600) rotors that are almost brand new. I have a 2008 BMW M roadster e85 that developed a pedal pulsation around 2019. It has the factory BMW floating drilled rotors. At the time I figured rotors were old - so I just replaced rotors / pads. Now, about 10,000 miles later - pulsation is back.

It’s not pad deposits. I sanded the rotors uniformly to bare fresh metal using 80 grit sandpaper & put on a new set of semi metallic pads - no change. Replaced factory front control arm bushings. They had tiny tears in the rubber - so they needed to be replaced regardless.

It’s hard to check rotor runout on drilled rotors. The dial indicator just goes into the holes. I did a quick check on the top edge of the rotors & runout was about 0.0025” max. The rotors only have 10k miles gentle braking on them.

Anyway, I’ve replaced/ruled out everything except hubs or paint on re-powder coated wheels making the wheel not sit flush on the hub. I measured runout on the hubs & it was almost non existent. I’ve always cleaned the hubs when removing the wheels & put a light coat of anti-seize on them - which may have not been best idea.

I believe there likely is thickness variation in the rotor. I have to pull the wheels & order a deeper micrometer so I can measure lower down on the rotor toward the hat.

Anyway, once I find the culprit I’d love to find someone with a lathe who would cut these rotors. I know BMW doesn’t recommend it & cutting floating rotors isn’t recommended - but we used to do it all the time. Worse issue was some chatter until pads bedded to rotor. I’m trying to avoided putting out another $600 for rotors that are still thick.

What’s the industries current stance on cutting rotors & any idea how to go about finding someone who does it correctly? Any indy shops still doing this?