[bluejudge]

This is the first time I am getting these rotors cut, they are the drilled and slotted rotors. I just want to make sure they can be cut like the regular rotors. Thanks, Marc.

[67GTONUT]

I was under the impression that Drilled rotors could not be cut....

[dataway]

I'm no expert on cutting disks, but I know from machine work that "interrupted" cuts on something with holes or slots in it can be tough on tooling.

[poncho4554spd]

I myself toss them but they can be cut if done carefully and at a slow speed.

[bluejudge]

Went to Pep Boys today and they said they can't be cut.

[Fullsize455]

Yeah, drilled and/or slotted rotors can't be machined in a brake lathe, regardless of brand and such. Also, drilled and slotted rotors are of absolutely no value on a street car, unless you're after a "look". Drilled and slotted rotors will show no benefit whatsoever over an equivalent blank rotor unless you are pushing it hard for prolonged periods on a track. They are also more prone to cracking and other issues that blank rotors are not, so unless they are absolutely necessary I would avoid them.

[dataway]

Why no stainless rotors on vehicles these days? Motorcycles have had stainless rotors for decades now, they last forever, have great stopping power and of course never rust. The rotors on a 160 hp sport bike take tremendous abuse so it can't be temperature problems I don't think .... might be I guess. A bike rotor of course gets tons of air flow, and they are thin, less than 1/4" thick.

I've seen SS rotors for trailer brake kits ... but don't recall seeing them for cars.

[Fullsize455]

Stainless steel has absolutely horrible thermal properties, among other issues(like cost). Cast iron is by far the best material to use for most brake rotors, as it has excellent thermal properties, it is very strong, does not readily warp, it is easy to work with and low cost. Motorcycle brakes do not deal with anything like the heat buildup that car/truck rotors deal with, due to their significantly lower weight relative to the swept area of the rotors and vastly superior cooling,, so temperature is not an issue. Most performance motorcycles have brake rotors approaching the same diameter as a typical car rotor, despite having to stop roughly 1/10th the weight.

Not to mention, rust is a much larger problem for motorcycle brake rotors, which are often exposed to and come in direct contact with significantly more moisture, and being far thinner they have far less tolerance for rust-related structural issues than a large, thick car rotor. The heavy, flaky rust familiar to anyone who lives in the rust belt would result in a typical motorcycle brake rotor fracturing right at the hub or otherwise failing completely, with predictably disastrous results. Not to mention appearance concerns. I suspect the fact that many(most?) motorcycles use stainless rotors is because the particular goods in the context of a motorcycle outweigh the bad.

[poncho4554spd]

Like I said, they can be cut with the right equipment and procedure, though I myself would rather buy new.

[dataway]

Fullsize ... yep, that sounds right. The disks on my bike are larger in diameter than my truck and have three pistons each. Incredible the power they have with just a couple of fingers on the lever and of course no power assist.

[Fullsize455]

Originally Posted by dataway

Fullsize ... yep, that sounds right. The disks on my bike are larger in diameter than my truck and have three pistons each. Incredible the power they have with just a couple of fingers on the lever and of course no power assist.

Yep. There's another practical limitation on a bike as well - tires. Even relative to the lighter weight, a motorcycle tire contact patch is absolutely miniscule, so even with all the brake in the world you're still limited by how much braking force the tire can actually apply to the road. The large diameter rotors with multi-piston calipers help with modulation and feel, as well as to minimize heat buildup in the rotors.

[bluejudge]

The rear brakes were good except for one side. The drivers side rotor was fine and the pads were maybe half way used. The passenger side only
the outer pad started digging into the rotor. Is something wrong with the caliber? Someone said the caliber could be bad.