VTRsurfer

And I told you the rotors can't be machined.

I rarely use the rear brake, since it's the front brake that stops the bike. Although I do use it lightly a couple times per ride just to keep it working. Both brakes are important, but from your opening post it sounds like you are uncomfortable using primarily the front brake. That's not good.

I taught classes on Automotive Brake and Suspension for over 30 years, and even on a car the front brakes do most of the stopping. It's up to 85% front brakes during a hard stop on some front wheel drives. It's about 60/40 on rear wheel drives. On motorcycles the front brake does up to 100% of the braking. Have you ever seen a road racer brake so hard that the rear tire comes off the pavement?

Tweety

You seriously need to grow a thicker skin... That wasn't rude... Having a different opinion isn't rude, it's just a starting point for a discussion... BTW that info wasn't in the first post... Ie then one has to assume you have worn down a perfectly normal rear pad...

I have yet to need to swap the pads on the rear of my bike after some 150 000 miles...

You can machine the rotors, but it's not recommended... Get new pads and rotor in one go, clean all of it up and mount it and bed it in...

But yeah, start working on mentally moving your breaking to the front brake... You will thank us when you need to stock quick to avoid a collision... The rear is so much less effective, both because of it's size, and becasue you need to put weight on the fork to be able to stop safely in a short distance...

1971allchaos

WELLLLLL, ALLL Righty then ! ! I learned some new info, As always....

Thinking about VTRsurfer's responce- and how informative it was- How his opinion was taken- I would have suggested to "VIPER tt" to go pull up the e-Brake on that supra at 60mph, then do the same -applying the brakes normally. and tell us -WHERE does he feel the stopping...and which procedure has the most control in stopping.
I believe that would support his questioning VTRsurfer's opinion...

comedo

I had to put a new rear disc on my 2001 VTR this year. The stock disc was worn noticeably after about 70,000 km. I was very surprised that it had worn as much as it had.
Like other contributors, I recognize the importance of proper use of the front brakes. However, an unladen VTR has a weight bias toward the rear. My experience has been that no matter how hard I use the front brakes the rear wheel doesn't leave the ground. As long as the back wheel is rotating and is in contact with the ground, the rear brake can be used to slow the motorcycle. I usually have light pressure on the back brake when I do hard stops or slow the bike significantly at high speeds.
I use the rear brake heavily when I'm doing full lock turns at low speed. I hold the throttle steady, feather the clutch and control speed with the back brake.
I've had to change the pads on rear discs of other bikes I've owned but I've never had to change a rear disc before. As I said, I was surprised that I had to with the VTR.

Stevebis1

AND yet Viperkillertt wasn't asking for a lesson on braking, he just wanted to know if it is COMMON to replace rotors when replacing pads.
Viper - I can't tell you what others may consider common, but I can tell you I have never replaced a motorcycle rotor but I have replaced pads. Obviously the service manual provides the spec, but if not under that and if the rotors are not seriously scored (they may be based on your grinding noise comment) AND considering it is the back brake - if it all looked good I would just replace the pad.
my .02

RWhisen

I suppose you COULD have them machined since the minimum thickness is stamped right on the rotor. I don't think you could have them machined in the way that you do automobile rotors without some sort of jig to hold them in the turning machine. Other than that the only other machine you could use would be a "Blanchard" flat grinder.

http://www.youtube.com/watch?v=sesxx-U_0FU

I think the cost associated with either of these courses of action would make the purchase of new rotors seem reasonable.


P.S. I use my back brakes a lot too. Holdover from my motocross days.....

Wicky

What scares me is viperkillertt said the "serious grinding noise about 2 weeks ago" which indicates a pad/the pads are more than likely worn down to metal. Surely in that situation it would be best to have undone a couple of bolts and examine what on earth is going on with pad wear as soon as possible. Still better to have not got into that situation in the first place with preemptive maintenance.

Anyway to recover from the situation of a prematurely worn disk /rotor is to get a good condition second hand one off ebay

part no 43251-KEA-000

Also fits CBr600F2/3/4, CBR900RR, CBR600SJR, XR650L which widen the choice