We are big fans of bells here at Commute By Bike. Every good commuter bike, or bicycle that is ridden near people and dogs, should have some sort of bell attached to it. After many years of trying various bells, some expensive and some inexpensive, I think Velo Orange has crafted my favorite for the city commuter.
The Velo Orange Brass Temple Bell attaches to only certain handlebars due to the limited clamp diameter. I would say it is safe to install it on a straight bar, townie or anything without an over-sized design. This bell is also pretty inexpensive at $8.00. You can save your pennies and install one on every bike you own… For a bell with better mounting choices, check out the Japanese Bell with Retro Space Mount.