Where are you riding
Bike bells are important if you ride in environments where there are other users. Pedestrians, other cyclists and motorists. You need to use a bike bell to be heard to ensure safety for yourself and others on bike paths, shared paths, dual direction mountain bike trails, blind corners, the road and at times so motorists can hear you. See Be heard with Bike Bells
What type of riding do you do
There are bike bells more suited to different types of riding. On a mountain bike you do not want a bell that protrudes as it could get in the way and be easily damaged so consider a sleek minimalist bell – the Knog Oi. The commuter, urban, bike path rider is more suited to traditional type of bells.
The age and skill of the rider
If the rider is young or a beginner consider if they can still control their steering to operate the bell. Can you position a traditional bell so they don’t become challenged with their steering. You can get bells with remote triggers that can be fitted right where their thumb is – so there steering doesn’t become compromised – the super fun Mini Hornet with its 25 sounds. See Bike Bells and Bike Lights for Kids
There are varying quality of bells. Cheaper bells do not last very long and often have a poor ‘ring’ to them.