Stroll on the Wild Side part 2 - S5-E8
Revealing mistake: Towards the end of the episode, when Murdoch attacks Falcone, look closely: the first punch - which knocks the mob boss down - looks convincing but the second time Murdoch "hits" him, he punches nothing but the ground. Falcone is facing right while the detective strikes his left side, at least an inch away from his head.
Answer: It's certainly a personal choice about using one, and probably similar to how some people refuse to wear a helmet or forego other safety equipment. Most bells and horns on bikes are not very loud and probably wouldn't be heard in busy traffic, making them mostly ineffective. Murdoch would likely still yell, even if he had a bell or horn.
raywest ★