racerdave
^ Gone not forgotten ^
I need a rear XS650 rotor drilled. I want a swirl pattern, similar to my EBC front. It has 9 rows of 5. I'd guess there would be less with the smaller dia rear rotor
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Do we have a forum member that drills brake rotor's?
Royboy
many roads, little time
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Dave, Here is the rear rotor on my 78'SR500. I drilled it the other day, just using my drill press and the turntable. Pretty simple really. Laid it out on paper template using a protractor in maybe five minutes. Predrilled holes with a 1/8th bit and then went to 1/4" bit to finish. Would probably go 5/16ths next time.
roy
roy
Attachments
thelowlife
XS650 Addict
http://www.xs650.com/forum/showthread.php?t=12671
I think I put the rear pattern in that thread (too lazy to check right now).. if not just pm with the dimensions and I can make the pattern you need.
I think I put the rear pattern in that thread (too lazy to check right now).. if not just pm with the dimensions and I can make the pattern you need.
.......................... hi there,s a great guy in new zealand..... goran persson that supplied me a few years ago with tech drawings oto transfer to a disc ,, they are simple to read and the drilling patterns are great it could be worth chasing him up ........... also you could use a titanium coated drill bit to drill st/st they,ll do it without dramas at all...i,ve used alot in contracting ,,,, they are not that expensive for the amount you would buy regards oldbiker
Royboy
many roads, little time
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These stock rotors drill without problems. I bought a couple new cobalt bits before I started on the SR rotor and think I could have done 10 rotors without a bit change. Just need to keep the bit speed at about 400 rpm. Dave, if you want just send me a pm. I'll drill that rotor for you for postage.
roy
roy
racerdave
^ Gone not forgotten ^
Roy pm sent
jd750ace
Front Toward Enemy
You would be REAL tired. It's generally speaking a LOT of drilling in stainless. You have to keep the pressure up, the speed down, and a bit of lube or an air nozzle helps on keeping things cooled down and your bits lasting longer. The kind of pressure required to keep a good bite going alone would wear me out, and I hand drill for a living. Speed (below 400 RPM as mentioned) is very important, and staying straight is in your best interest as well. If you did try to hand drill it, I'd suggest a drill bushing, to stay square, which would only complicate the job further. Over cook the speed and work harden a spot, and it's a bitch to get back into and through with a bit. I hit the occasional hard spot when drilling mine (84 holes, IIRC) and was glad I was in the press, as a quick increase in pressure to get a bite is easier with the press.
Borrow a table top press if you have to, but not a job to free hand, IMO.
Holes do give the bike a racier look. Lots of people do the drilling for that reason. There are performance increases to the brakes if done right.
A few things to remember, holes should not be any bigger than the rotor is thick. Holes at or below thickness increase cooling area, once you go bigger the cooling area decreases.
Another thing is that the holes should over lap the row next to them. So the whole swept area is covered. You can see this in racerdave's pic. The row of holes on the outside edge are overlapped by the second row. Second by third, and so fourth.
The holes should have a sharp edge. No burrs from drilling, but no bevel. As the rotor wears, the bits of steel imbed in the pads, this reduces grip. The sharp edge of the holes clean these bits of steel off. That is one reason why the holes should over lap. That way the whole swept area stays clean.
As you use the brakes heat is created. This heat causes out gassing of the pads. This out gassing can lift the pads off the rotor. The holes let this outgassing escape. Over lapping the holes helps here too.
Leo
A few things to remember, holes should not be any bigger than the rotor is thick. Holes at or below thickness increase cooling area, once you go bigger the cooling area decreases.
Another thing is that the holes should over lap the row next to them. So the whole swept area is covered. You can see this in racerdave's pic. The row of holes on the outside edge are overlapped by the second row. Second by third, and so fourth.
The holes should have a sharp edge. No burrs from drilling, but no bevel. As the rotor wears, the bits of steel imbed in the pads, this reduces grip. The sharp edge of the holes clean these bits of steel off. That is one reason why the holes should over lap. That way the whole swept area stays clean.
As you use the brakes heat is created. This heat causes out gassing of the pads. This out gassing can lift the pads off the rotor. The holes let this outgassing escape. Over lapping the holes helps here too.
Leo
