There is no hot oil in, on, or near your bike.
Maybe you got stung by a bee or snake bit? Maybe one of those subterranean cannibalistic humanoids took a swipe at you from a storm drain? Perhaps one of Obama's drones took a laser shot at you?
Those would be the most common things that would cause that.
There are a couple dozen less common possibilities like Land Shark bites or an attempted but aborted alien abduction but we need more info.
Did it back fire? Did you fire back?
