First heat of the day, did two laps... on the third completely lost front brakes (as seen on the video at 8:10~)... Luckily was a rather slow corner and the gravel trap shaved most of the speed, ended up falling almost stopped. After that brakes were bled, calipers cleaned. Went out again, and again on the third lap brakes completely gone again. I was braking early as a precaution, rear brake and downshifting helped me make the corner. After about 5 minutes brake would come back I installed Brembo Oro rotors... and calipers are stock, but not the same pair I used in other trackdays (long story). After both brake failures front wheel seemed really stuck, as if the calipers weren't opening enough... I'm thinking in upgrading to carbon brake pads, but I'm still not sure what caused today's apparent overheating...
My money is on boiled brake fluid on the basis that the lever went all the way back with no braking at all and then returned to normal once it had cooled down. I had exactly the same thing on a mates road bike at Cadwell Park. It boiled the brakes, I ended up going straight on, then I nursed it round the remainder of the track and as soon as I pulled back into the paddock the brakes were fine again.It really should be as simple as flushing the system with the correct type of fluid (I use Motul RBF660). The issue starts from the calliper end where the heat transfers up the brake lines, but you should bleed the master cylinder too.
Yeah, most likely. However after the crash both calipers and master cylinder were bled. Did a couple of laps and it failed again. I will use a different brake oil next time, thanks for the tip.
Glad your ok. I was at Donny last year and a guy had to throw himself off his bike due to a similar issue. I only heard about it, didn’t see it. Thankfully he was alright.