[ywlgy]

Hi,

1 year old G21 has rust on the back side of brake disc, as shown in the attached picture.

This only happens to the front wheels. I've also checked my friend's 5 years old G20 and his is rust free!

Is this normal?

[Throatpunch]

Normal but mine got worse from my wheel cleaner

[ywlgy]

Originally Posted by Throatpunch

Normal but mine got worse from my wheel cleaner

Thanks for confirming. I am curious why it happens to only front wheels. Do they use different materials for front and rear disc?

[GOTOFMS]

front brakes tend to get hotter. maybe the coating cooked off the rotor. just a guess.

[Throatpunch]

Originally Posted by GOTOFMS

front brakes tend to get hotter. maybe the coating cooked off the rotor. just a guess.

I agree with that. More expansion happening in front. Then cracks in coating create ability to rust