15 ms·Its pretty safe to assume on a trail if you hear a bell that a bike is coming up behind you.by samdixon 5mo agoIts pretty safe to assume on a trail if you hear a bell that a bike is coming up behind you.jandrese 5mo agoOr from the side or oncoming and he's just behind the crowd of pedestrians ahead of you.samdixon 5mo agoYes haha - a bike coming from _somewhere_