So, a new bike, Avid Elixir 5 180mm front and rear. My second ride was on a short dirt road, 340m denivelation.
I held the brakes (mainly the front) more than 50% of the time, as the road was too steep for my skills.
At the end of the descent, there was slight smell of burnt plastic, coming from the front calliper.
What has caused this and is it at reason for concern?
On another account, a couple of Tektro Augura smelled severely of burnt plastic at the middle of the descent (another bike, another rider). She finished the descent and has not seen ill effect since (well, the front braking is not as good as before, but no idea if this is since that happening or later).