[2021-08-10]
Changed the bell spring to circular shape. Should better distribute the stress.

For a long time I've had a nice bike bell with a clever design - just a single piece of plastics, easy to mount, no screws. The plastics started to wear out so I've decided to create a copy and improve the design a bit to strengthen some parts. Simulation from Fusion360 shows no significant local stress - see the pictures of stress and safety simulations with 10N of static pressure.

The design should work with any metal bike bell top. If you have a bell of different diameter, the Fusion360 file is included so you can modify it to fit your bell. Don't forget to put a piece of rubber (for example a cut from a bike tube) between the bell mount and handlebars to increase adhesion.

PETG is probably the best material for the print. I've also tried ABS and ASA. ABS broke after a month or so, ASA lasted for almost a year.