A couple of days ago I fell off my bike. I was on a wet, steep downhill, asphalted road with a lot of curves. I didn't expect neither the weather, nor the 15+ km downhill route. I was always reducing my speed to 9-10 kph before taking a turn. However, just after a taking a turn and before another curve, when I pressed the rear brake lever, the wheel stopped turning immediately, despite the slight pressure, and started to slide. Worse, the bike didn't stop, it started to accelerate. I pressed the front brake lever, slowly initially, but since the bike was still accelerating, I pressed more was thrown off. Never mind the damage; I got off with minor injuries, the bike as well. This could have been due to my being careful to begin with, but not enough, apparently, so my question is how can I be better prepared in the future? And what might have caused the tyre to slide? The road was wet and with minor holes and bumps, sure, but I had gone through similar terrain seconds ago and I could brake just fine. And I'm sure I didn't press the lever way too hard than perceived. Also, there wasn't any wet sand. None that I could see anyway.
In hindsight, there are a few things that came to my mind. I'm not entirely sure about any of them, however, since I have just recently started to cycle since my childhood/high school years and I just discovered that there was stuff I was missing out on back then (such as bike fitting and geometry).
The saddle could've been lowered. I normally ride so that my knees bend at a 25-30 degrees at the pedals' lowest position. I assume lowering the saddle would've necessitated much more effort from the front brake to throw me.
My bike is suited for XC racing. Would picking a downhill bike, with the appropriate frame geometry, have made a difference, provided we're talking about an asphalted road?
Should I have kept the rear or both brakes engaged constantly? At the time, I didn't want to do this out of fear that they, being disc brakes, would overheat and the rotor would be destroyed. The route I was on was at least 28 km long, mostly steep downhill, save for the last 10 km or so, which were a rather pleasant, slight descent.