[Ease]

I'm guessing a few - if not all - of you have drilled your rotors at some point (or at least though about it).
3 Questions:

1. I was wondering if you had to have your rotors re-surfaced after drilling.
2. For dual disk setup, do you just clamp the 2 together, or is this too much stress on the bit?
3. Should I countersink the holes with a larger drill bit?

Also, what is the best bit to use? I have a small drill press, but I don't want to have to crack off 10 bits before I get em done.

I read the article in the search function (http://eindiancompanies.com/howto/howtorotor.htm) - seems to answer #2 and 3 - but I was wondering, from your own personal experience.

Hey By'

 

[jbranson]

On stainless steel disks you want to turn the bit relatively slow, and with considerable feed force. SS work hardens quickly, if you turn the bit fast and use low pressure it just trys to harden a layer of metal and becomes very hard to drill.
I've seen the holes with a slight chamfer on the edge...and I've seen them without.
A single good cobalt drill bit should do them both.
JohnnyB

 

[jbranson]

On stainless steel disks you want to turn the bit relatively slow, and with considerable feed force. SS work hardens quickly, if you turn the bit fast and use low pressure it just trys to harden a layer of metal and becomes very hard to drill.
I've seen the holes with a slight chamfer on the edge...and I've seen them without.
A single good cobalt drill bit should do them both.
JohnnyB

 

[parks61]

either find pre drilled rotors or just don't do it. the lay out (of holes) is really important to maintain strength and balance. the benefits are marginal. even if all is perfect after all the machining, the warp factor after the first really hot heat cycle is a wild card as well.
parks

 

[KeninIowa]

My nephew did two rotors for my 550. He made a fixture to locate and to chuck off the center hole. Faced them on a lathe mostly for appearance but to also make sure they were perfectly true. Drilled them on a mill. Was gonna use a super spacer but it had a problem so we used the DRO to locate the holes. So after all this ended up with one usable rotor and one warped rotor. My theory for this is that he wasn't happy with my feed rate, was ready to go home and started punching the holes a lot faster than I had been on the second rotor. I'm just saying they're pretty easy to screw up.

04 KDX 200
05 KX 250f- SOLD!
01 GSXR 750
75 GT 550
68 Chevelle

 

[Ease]

So the consensus here is that you guys don't drill your own brakes?

Seemed to me that the large majority of cafe racers online have drilled rotors - and I can only assume they aren't factory drilled... Except on maybe race bikes with aftermarket setups (or modern setups from other bikes).

My plan wasn't to swiss cheese the rotors - or for huge performance gains. I have dual discs on a fairly light bike, so it stops fine.
More cosmetic I suppose - But I figured with better pads, and the added cooling (and lighter weight) of a few holes, it'd be win-win (good cafe-style looks and some moderate performance gains).

This is what I had in Mind:

Hey By'

 

[joe c]

there is a guy on ebay who does them. in 2 patterns. if you go to the chivinmoto list, and ask there, or the nycvinmoto list, you can ask about a guy who does them for like 65 bucks or something like that. mike morse at vintage brake does em too.





jc

aaron sent my wheel!

 

[KeninIowa]

I'm not saying it can't be done. When I get another rotor I'll make it match the one on the bike, cuz it does look cool. Just be aware of the potential pitfalls.

Side note; I had my wheel balanced with no rotors. The plan was to then install the rotors and see how they effected the balance. I couldn't think of any other way to check the balance of the rotors themselves. After the one didn't turn out I kinda said screw it and never did.

I'm sure the rotors wouldn't be out of balance bad enough that you couldn't compensate for it when balancing the whole assembly. But in my mind there would still be undersirable things going on if the rotors themselves weren't neutral.

04 KDX 200
05 KX 250f- SOLD!
01 GSXR 750
75 GT 550
68 Chevelle