Does anyone offer a slotting service for brake roters?

Not for looks but for performance, I've read that slotted rotors offer better stopping power and help cool and keep water, oil, and dust from coating the brakes. Does anyone know of a machine shop that does mail orders or any other websites that offer this service?
Thanks

http://www.xs650.com/forum/showthread.php?t=12671&highlight=rotor+drilling

slotting doesn't need to be all the way through to work, grooves work just as well, around 0.050" deep should be plenty.
Carbide milling cutter should work, although I haven't tried it (although I may, now I've had it brought to my attention ;D )

I'd love to see what you end up with PJ. Keep us posted

I'd check with the guys over at Dime City Cycles. I know they offer mail-in service, and I've seen slotted rotors on the bikes that they build.

Ask Hurley- he does drilled rotors for minimal $$$.

For street driving, drilling or slotting an old rotor is only going to make things more dangerous, and threaten your brakes ability to function at all.

Drilling or slotting vintage brake rotors introduces stress concentrations for cracks to form, reduces the amount of metal present to absorb heat, decreases pad life, and reduces clamped area of your pads. Brake rotors are machined in the annealed state, and then hardened afterward, so buying properly made slotted/drilled rotors avoids the stress cracking issues. Drilled rotors will help with performance at some extreme situations of braking, but don't work at all when cracked in half. A rotor cracking in half in a car on the track is just a bad day, you have 3 more wheels with brakes. The same can't really be said for a motorcycle. If you are worried about grease or debris, hit your pads with some brake cleaner once a month.

On the street, you would be much better served by buying some expensive ceramic brake pads and having your rotor re-dressed. Buy a stainless steel jacketed brake line, that way more of your handle pull is transmitted to the caliper more quickly. If you were on the track, there are some benefits to slotted/drilled rotors, but there is next to none on the street, especially when done to a hardened rotor that wasn't made that way in the first place.

If you are really looking for performance, spend the money on better pad materials, new brake fluid, and a brake line. If you can, find an aftermarket drilled rotor for your bike. Just don't go drilling 60 holes in a rotor. Your call of course, just giving my 2 cents.

On a street driven bike, I doubt you would see major issues with drilling a rotor, I'll grant you that. There is a reason people aren't dying every day from exploding rotors they drilled in their garage. This doesn't change the fact that it is bad from a metallurgical, brake performance, and safety point of view. I haven't done it to any of my vehicles for that very reason. Drilled rotors were created to fix the problem of out-gassing Asbestos pads. Modern pads of any quality simply don't do that at reasonable temperatures. If you are heating your brakes up that much, your DOT-3 brake fluid has already boiled off to the point that "brake fade" is an understatement.

It should be telling that Formula 1 brakes are solid surface vented discs... http://www.formula1.com/inside_f1/understanding_the_sport/5284.html

Modern motorcycle brakes sometimes have drilled holes in them to lighten them, because frankly, the brakes are already so grossly overpowered that they are intentionally trading braking power for reduced rotational mass. The result is still a brake system that can lock the tire, but also weighs less (and looks cool). They are also MADE that way, not drilled after the fact. If you can lock your tire, the brakes are powerful enough. On the track you can worry about brake fade, etc.

Once again, I'm not saying that drilling a rotor doesn't work... I'm just saying to look around at legitimate sources for advanced vehicle engineering, not a motorcyle guru and the postings of some forumites.

I guess most of what your saying could be true in theory, however in practice there are multiple advantages to drilling/slotting rotors, drilling and slotting decreases weight which decreases un-sprung weight and helps tyres/suspension function
On a street bike, slotting is more effective for water dispersion, holes tend to steam up and create a boundary layer although it is still an improvement over solid discs (or so I've read from people who experiment with these things)
None are hardened after being made, they work/age harden naturally
The only rotors I've ever seen crack were used for racing, guy kept using them as he said the cracks helped braking rotors no longer distorted when overheated (TL1000R motor in a 'Legends' type car using Honda street discs thinned to 5mm )
I drilled oversize holes in my XS rotors about 8 ~9 yrs ago, they are in better condition now than they were when I did them (I would have used 1/4"~6mm if I was staying with single disc but I upgraded to dual and fitted Suzuki 4 pot calipers)
Yamaha rotors/pads are 'famous' for getting material embedded and tearing up rotor, the holes allow even pad/rotor wear and IS better than stock (at least with dual discs)
Using stock single disc rotors also means I have larger diameter than the genuine Yamaha dual disc rotors (298mm vs 275mm)
I've also drilled a lot of Honda rotors without any issues.
One thing you do need to check or work to be effective, the 'edges' of the holes have to 'overlap' slightly or wear ridges will develop where rotor is in effect still 'solid'

Am I a motorcycle engineer? No, but I am a mechanical engineer at Delphi, an automotive OEM supplier. For the record though, I was counting myself among the "random forumites" whose advice I want the OP to take with a grain of salt.

The 'butt dyno' has been proven wrong time and time again, but people still seem to swear by it... and "works fine" is not the same as "works better". I can lock the front wheel up with the single disc brake on my CX500 with ceramic pads and stainless brake lines, though I'll grant that I'm not exactly running sticky race rubber tires.

Not worth me posting more, we could do this all day lol. :-X OP needs to make their own determination. Sorry if I derailed this thread or ruffled any feathers

For the record I am rebuilding the system. Rebuilding the caliper, master cylinders and also just got all new lines including the hard line. The two soft lines are stainless steel braided. Just looking for that extra edge. To get out of my area I have to drive down hill for 3-5 miles at steep grade at some places so I'm looking for every advantage

midgtmn said:

Am I a motorcycle engineer? No, but I am a mechanical engineer at Delphi, an automotive OEM supplier. For the record though, I was counting myself among the "random forumites" whose advice I want the OP to take with a grain of salt.

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Cool, do you ever do testing with different grades of stainless steel rotors?
Early 70's had a higher chrome content than late 70's/80's, (except for Yamaha who probably used lower chrome content than Honda as Yamaha rotors would 'rust' if left long enough?)

Keep posting, it's good to have expert opinions (as compared to opinions ;D )
I'm not an engineer, just been working on bikes for over 40yrs and learned as much related to motorcycle technology as I can

I don't have any experience of ceramic pads, but, may be a good idea if they have lower heat transference than 'stock' type pads and don't require special treatment

Oh, forgot to mention, I use DOT 4 minimum but usually DOT 5.1? (not the silicon fluid)