Causes, in most cases, are speculative. With no first-hand eyewitness or proper investigation, the cause of such a crash will either live or die with the victim/s. What we CAN take away from this is: slow down in high-risk Urban areas, don't ride faster than you can respond, get trained well, and fully comprehend the environment in which you ride.
We ride our motorcycles in a constantly changing environment, a time and space that we are not in control of; BUT we can control how we ride, and what we wear when we ride. Ignoring these facts will result in you being the cause of your own crash -- I pray that you don't!
Let's look at 3 of the most common traits.
Cause 1: Speed
Too fast is when your mind can't keep up or react in time to avoid incident or collision. Allowing the bike to lead, leaves the rider out of control which compromises a safe or secure response zone. Proper and regular training sharpens the mind and senses, when repeated and applied, builds muscle and mental memory to successfully avoid or minimize risk. Real men race on the track, not the road!
Cause 2: Size
Big bikes can easily weigh more than 300kg, making them significantly harder to handle in tight turns and at slower speeds. A powerful engine also requires a level of control that some riders just don't have, as even a minor twist of the throttle may result in an unintentional bolt in the wrong direction. A squid is a rider who, overconfident in his or her abilities, jumps on a big or powerful motorcycle to compensate for their inexperience and to impress their friends.
Riding a motorcycle is a risk, hands down, but we CAN do something to minimise that risk. Change starts with you!
Cause 3: Attitude
The Selfish Road User, or as I like to call it, "arrogant ignorance" is the decision not to think! Some are so self-absorbed, that they would rather risk life than acknowledge their own incompetence. This demon occupies both sides of the "road user" fence. The only difference between a good day, and a bad day, is your attitude. Make it count!