aaa rear break rotor question

[anthonygs1000]

is the rear break rotor supposed to be flat because every one i see looks beat up ? thanks anthony

[beRto]

What do you mean by beat up? The rotor can't be warped, if that's what you mean. Or do you mean that the perimeter is bumpy? If so, it might be an aftermarket rotor.

Mine is smooth around the edge (and not warped either!  ):



... and yes, that stock Excedra tire has since been replaced.

[spc]

Who the f%$k would put a wave rotor on the ass end of a GS?
I think he means scored/grooved..........people tend to never change rear pads not realizing their usefulness and end up killing the rotor.

[ohgood]

I know what you mean.

I always figured it was because the disc gets really really hot, then cools quickly. When grinding tool steel with too much feed rate, if there is a hole (like the cooling hole in our rotors) the grinding wheel would heat the work (rotor) but it would cool faster NEARER the hole, because of more surface area, radiation, etc.

Where there isn't a hole, the rotor would stay HOT longer, and the wheel would grind off more, creating a depression. Some people call it 'chatter' but that's not technically correct. Chatter is from a tool bit digging in, and blah blah blah, a whole other subject. it LOOKS like chatter, but isn't.

Soo, you have a hotter spot, that gets abraded by your pad, and then there is a 'ripple' next to it also, maybe an after effect of the first depression cooling faster now than the surrounding rotor ?

You could take the rotor off, and have it blanchard ground (which would be super sexy and pretty with all the swirls!) but I'd bet the dimples would return within 500 miles from the heat cycles and grinding action of your pads + road grime.

Why don't the front do it as bad ? Got me, kinda figured it was because there was ALOT more surface area, which means more cooling, and more area to distribute the wear.

So long as the disc is within tolerance, and the pads are in decent shape, and, well, it stops the bike, I wouldn't worry about it

Now, someone's going to point to a really cool article online (with pictures and maybe an animation) that proves another theory all together

PS - if you have a 'break' rotor, you want a new one

[anthonygs1000]

LOL ya I know what you mean  thanks for the feed back and as long as it works   dont care how it looks thanks anthony