Front/Rear Brake Rotor Temp?

[st11ray]

Does anyone know what the surface temperature normally runs on the front and rear rotors? I rode through town today about 20 miles and when I got home I checked the temps. After parking and getting my gear off I read 95 degrees on the fronts and 115 on the rear. Does that sound about right? I was riding very easy and barely using the brakes.

 

[dwalby]

Re: Front/Rear Brake Rotar Temp?

hard to say for sure, too many variables are involved. under reasonable brake usage they're too hot to touch until you give them a few minutes to cool off. Depends on when the 'barely using' happened relative to parking the bike. Given the heat capacity of the rotors 95/115 is barely warm. If you're trying to determine if you have a dragging caliper I'd measure before a ride, stay off that brake entirely during the ride, and measure again after a short ride. If you have linked brakes, then it's probably not possible to do that test.

edit: years ago I was at Laguna Seca for a WSB race and was hanging out in the pits during practice. One of the riders came in for a tire change and they accidentally tossed the front wheel against one of those white 5 gallon buckets with cement inside that they use to anchor down their canopies. the rotor leaned into the plastic bucket and melted it like a hot knife through butter.

 

[Tom Mac 04a]

Re: Front/Rear Brake Rotar Temp?

Normal operating brakes IN normal use ( not carving up deals gap ) should be able to pass what i call the "touch test".

Real pain to the fingers starts at around 140d F ( damage can start to occur at 120+ if held ). At 140f, you can prob keep a finger on for a second. Up to 180d F you prob can't do more than a real fast on/off and a curse...with something like dammmm that's fracking hot.

So some where a bit above 140d F I usu fine my rotors ending up after a normal ride... too hot to hold more than a second or two, but not hot enough a that a burn occurs from a 'quick' touch. Anything more than that, something is prob sticking a bit if your not in stop/go traffic or heavy on brakes due to ride.

At your temps, they are very LOW , or as stated warm, doesn't sound abnormal if barely using the brakes.

 

[Blrfl]

Check the temperatures immediately after you come to a stop. The rotors cool off fairly quickly since they have the entire wheel as a heat sink.

My usual routine after I do brake work is to do some stops from progressively higher speeds, pull over someplace, hop off and measure the rotor temperatures with a non-contact pyrometer. I wouldn't worry about anything below about 160?F.

--Mark