[TR] TR6 Brake Rotor Groove

[suhringtr36 at comcast.net]

I've been meaning to ask this question since last fall, but thought it was a good time to get around to it now that the thaw is starting here in PA.  I developed a grove in the right front brake rotor of my '70 TR6 two summers ago. I noticed it on the way up to Watkins Glen but nothing detering continued driving. This was on the inside face of the rotor. At Carlisle, I picked up 2 new rotors and proceeded to replace both rotors and brake pads. Well, when I put the 6 down for its winter rest this year, I noticed the same grove, but not as large, on the same spot of the right rotor! I have heard that you can get a bad/defective brake pad that develops a bump that will wear such a grove in a rotor, but to have it happen twice?  

Any other thoughts on what could be causing this or do I just play the odds, get a new rotor and replace the brake pad (I am not doing both sides this time)?  TIA

Scott Suhring
Mechanicsburg, PA
'70 TR6
'59 TR3A