I wouldn't do it just because of all the localized heat you would be putting in there. I know gsracer has a friend who waterjet cuts rotors for pretty cheap. I'd say it'd be worth the money to send it to him. NFC Racing is who cuts them.

That and I think you'd need a few drill bits to cut through the rotors. They are stupid hard.

 

http://qualitymachineco.com/

 

A buddy of mine just drilled holes (over 100 all together!) in all three of his old Gold Wing rotors and then he chamfered both the front and back sides of the holes to get rid of the sharp edges to prevent cracking/breakage (important step!) It took him lots of time and four cobalt drill bits plus the chamfer tool, but it was still far cheaper (for him) than buying rotors that were already drilled.

You only have a single, small rotor, so your time and effort would be much less. I would caution against going for the "big" hole process you are considering though. The ability to get a uniform, clean, and well chamfered hole of a large diameter will be impossible unless you are a machinist with the proper tools. Since you have a drill press, I'd suggest just enlarging all the holes you have slightly. That's not sexy or dramatic appearing, I know, BUT, a little metal removed from 25 holes (just as an example) will be easier for you to do well - and accurately - plus it will be 'gentler' on your rotor.

Ultimately, enlarging all the holes already there slightly will add up to the same amount of weight you'd save from a few big holes, PLUS it will leave you with a rotor that is (most likely) still safe to actually use. Removing large circles from metal that gets really(!) hot is risky. Cracks and breakage developing during use would be the concern.

If you 'go for it' please post before and after pics and let us know if you detect any benefits. Good luck!

Michael in Aurora, CO

 

Enlarging the current holes by a reasonable amount won't save anywhere near as much weight as big holes.

the second one is about what I want to do.

 

There would be much cleaner ways to do it then a holes saw. But the real question is, why? Knock off wave rotors are cheap enough on eBay and it won't all ghetto.

 

Yes, a mill is going to be better than using a hole saw. I'm now looking for someone to lighten it for me, hopefully I can get it done.

 

^wave rotors are not that light.

Lightened rotors are, well... light. And I think Junkie doesn't care if it is ghetto, he just wants a little less weight on his bike.

 

Then just take the whole rear brake system off :naughty:

If weight is really a concern maybe remove a few layers spray paint :dontknow:

 

A step bit would even work 100x better then a hole saw.

Still ghetto though.

 

How much weight could that possibly save? Are you racing it or something?

 

It's an easy rotating pound you cut out. Maybe a little more. Also makes it harder to lock up the rear wheel in a panic situation.