? pre-mature rotor wear

[Expidia]

Bike is a 2022 Powerfly FS9 Equipped. Only purchased a month ago
Around 200 miles so far.
No downhill mountains yet.

Front looks normal but rear already has copper color showing through. Pic was taken quickly, but there is more wear than it shows in pic on the other side.

Bike is supposed to have upgraded components and the rotors are: Shimano RT76, 6-bolt, 203mm.
Shimano XT M8120 4-piston hydraulic disc callipers.

I asked my local bike store if this looks like normal wear to him in such a short period of time and he said which do you brake harder with front or back and I said I try and pull them both at the same with the same pressure.

What say you? . . . normal wear or defective rotor on back? Or defective pads?

 

[cozzy]

Without measuring the thickness its impossible to say. 1.8mm when new I recall for Shimano stuff.

 

[RustyIron]

What say you? . . . normal wear or defective rotor on back? Or defective pads?

I see virtually no wear, so I wouldn't conclude that there is a defective rotor or defective pads. Nor is there any copper, beyond any trace amounts used in the stainless, so there is nothing to "show through." There is nothing wrong. Ride your bike, be happy.

 

[Expidia]

Without measuring the thickness its impossible to say. 1.8mm when new I recall for Shimano stuff.

Thx for your quick reply. I doubt that they are worn deep already as to lessen the OEM thickness. It’s jujst that these rotors are already showing burnishing with the copper color already showing through. I know rotors are a wear item but not in a months time with light use!

 

[Dax]

Measure the thickness, if they are in tolerance keep riding, if not buy a new rotor.

There shouldn't be anything other than stainless steel all the way down on a rt76.

This is fairly severe rotor wear on a rt76:

 

[irie]

There's a lot of muck (ground up dust?) on the rotors so there will be also on the pads. I would clean the calipers, rotors, and pads, and bed the brakes in again. My Shimano 203mm RT76 rotors measure 2mm BTW.