Brake Rotor Drilling Opinion...

One of my winter projects is a complete rebuild of the front brakes (rebuild MC, calipers and SS lines, pads etc..). I've also been reading about drilled rotors. Has anyone done this? Several sources have discussed this (http://www.ggjaguar.com/seca.htm) and an article in Cycle World, April 1991. The upgrade seems like it makes sense and I've also noticed that the later bikes have slotted rotors. All of this to reduce galling of the surface of the relatively soft steel of the rotors - providing better performance.

Thanks in advance!

 

I have.

Once I got my '81 550 Seca back on the road, with rebuilt brakes, stainless lines and OE Yamaha pads, I had a fading issue. After two or three 80mph - zero freeway hauldowns in short succession, the brake would fade to the point where the lever was nearly to the bar to get it stopped.

I took a good stock rotor and sent it out to get skimmed (Blanchard ground on both sides) and drilled.

Fading issue 90% solved. It now takes some serious abuse to induce any fading at all.

On the other bike, I replaced the original front disc with an EBC floating rotor, with EBC pads. It just doesn't fade, period.

That being said, I will probably get the discs on my 650 drilled rather than replace them unless they turn out to be warped.

Drilled stock rotor:




EBC brake:

 

Info on brakes http://www.vintagebrake.com/mastercylinder.htm

 

curious fitz - how much did it cost to have the stock rotor ground down and drilled? and where did you have the work done?

Thanks!

Chris

 

It was around $70, IIRC; and it was a race car brake place that advertises on eBay, or at least was when I had it done. I'll have to dig a bit to see if I can find their current info.

 

Thanks fitz for your reply. It makes sense that you want to squeeze every ounce of stopping power out of that single rotor on a 550. Thankfully the 650 has 2, albiet more weight to contend with. I look forward to finding out who did the work for you as I'm still inclined to have this done - you can't argue with wanting to make sure that you've got every advantage possible when it comes to stopping.

FYI, I've scanned the info I mentioned for anyone else who is interested, it's a decent article and covers the all of the "updates" across the XJ 650RJ. Anyone can contact me through private message on the site and I can email it to them....

 

I have a recollection this drilling thing was debunked somewhere. Along the lines of the less metal you have the less efficient the heat sink effect. Wave discs similar. How come modern bikes don't do it?

Mr ebc's view on things

http://www.ebcbrakes.com/cross_drilled_ ... tors.shtml

 

Brakes have come a long way in 30 years. Type of metal used, type of pad material, etc.

 

isint 70$ around what the ebc rotor cost?

were you wanting to keep it original, or what was your reason for drilling vs just going with a new ebc rotor?