During a neighborhood bicycle race a boy must survive the increasing signs of violent, psychopathic behavior of his younger brother.

Protagonist: Boy
Antagonist: younger brother
Stakes: The Boy's life / Survival
Story Goal: ?

I think that your premise has emotional potential, but currently it feels like the emotion is missing (in the logline). I am sure that as a screenwriter you have this story mapped out in your head as to the emotional predicament of a delusional and dangerous family member. But, in your current logline, it's emotionless. Possibly something regarding the race could be used to describe the younger brother which would give us an incite into the emotional conflict. "violently jealous" "selfishly psychotic" something in relation to the event of the race like this could be used. Just food for thought, would love a response with a link to the short film when it is made!