[Jeepmb]

Is a deep red color on the rotors bad for braking or dangerous? My bike used to be a rental bike at a ski resort and the rear rotor (160 mm Avid J3's) has red color around where the pad contacts but not where the pad contacts.

 

[ziscwg]

It heat discoloration.
If the rotor is not warped, your good. Check the pads. They may be glazed and not breaking as good as they could. Avid rotors tend to get hot and discolor easy anyway. Although, I never had one warp because of heat when I had my BB7.

 

[gticlay]

Mine get more of a purple color on the arms and it's fine like ziscwg said as long as they aren't warped too much.