It’s common knowledge brakes heat up during use, but how hot can they get? Simply put, pretty darn hot. Jason Fenske from Engineering Explained is back with another intriguing video made with help from a $55,000 FLIR thermal camera. This time, he points the camera at the brakes and takes some measurements.
The camera shows us five specific points where heat is registered: the leading edge of the brake pad, the rotor before the brake pad, the rotor after passing through the caliper, the wheel hub, and the back of the brake pad itself.
It’s interesting to see that the outer edge of the brake rotor registers as the hottest portion. This is due to slight rust that has formed on this rotor, which means the rotor isn’t as reflective, allowing the camera to read the highest temperatures. Jason says a warped rotor would produce similar results.
Another takeaway is the fact that the wheels seem to scrub some heat for the brakes. Heat from the brakes passes through the wheels and then to the outside air as the wheels spin. Potentially, different kinds of wheel material (aluminum, steel, or carbon fiber) may offer better braking performance through their ability to cool the rotors.
During normal street use, brake rotors and pads normally won’t see temperatures climb past 200 degrees Celsius, or 392 degrees Fahrenheit. However, track days are a different story, with temperatures potentially reaching 1,000 degrees Fahrenheit as the brakes are called upon more often and more aggressively.
We suppose if there’s one very simple thing to take away from this video it’s this: don’t touch your brake rotors after use. Your fingerprints will thank you later.