[Shibby]

Anybody know why my (front) Hayes 6" rotor (I'm using an HMX-1 caliper) has turned purple-grey on the braking surface (even after I wiped it off), and brown just below the braking surface on both sides. Sounds like heat discoloration, right? I guess so, I was doing a road ride today, and was braking pretty good (40 to 0 in a few seconds). Still, this hasn't happened on my hydraulic brakes....

 

[shocktower]

you got it really hot that is the discoloration from heat ,be careful those things burn I crashe at big bear and got this one

 

[shocktower]

my leg w/ rotor burn Big Bear

 

[Shibby]

holy shizniat, mang. that is crazy.

-shibby, purple rotor club

 

[vitox]

this is just a wild guess (hopefully someone more in the know will clarify...)
it might be that since the mechanical caliper hasnt got any oil to heat up, only the metal in the caliper itself, that more heat is left on the rotor so if heats up more,
that would maybe also explain why hayes doesnt like people to use the 8" rotor with the hmx........

v

 

[Shibby]

I would think that the 8" would be better, since there's a greater braking surface area for heat disappation. And yes, I think the lack of a heatsink in the HMX is probably what did it. And yes, they're still tinted purple. For some reason, they modulate better now tho On the other hand, they're way sensitive to operating temp (start riding home from the shop when cold, do one nose wheelie at a stop sign and they suck, do another a few seconds later, and they're rockin, wait 30 seconds, and they suck again. dammit!)

I'm going to Avids soon anyway... the HMX will be on a bike soon-to-be-sold.

Yaagh.