The Brass Duet Incredibell is one of the best bicycle bell out there. It's got the "beautifully resonant
ring of solid brass" and a striker that will not ring the bell no mater how many potholes you're riding over. Unfortunately the clamp will only fit handlebars with 21.7mm - 24mm (.86" - .95") outside diameters. I present to you a way to modify your bell to fit any handle bar width. Here the hacked bell is mounted upside down (just my preference, I like ringing with my right thumb, don't worry, rain will not get in the bell).
In addition to the bell, you will need a utility knife, screwdriver and a large clamp from most any front light mounting kit (the large size is almost never used so you might be able to get one for free at your local friendly bike shop, or bike dude/dudette)
First start by cutting away that inadequate clamp
cut a strait edge to mate with the trimmed bell. Wear eye protection when cutting the plastic, little bits of plastic can come at you.
Trim a 1/16" off this side and make square. check for fit up with the modified clamp
Insert the bolt from the incredibell into the threaded insert inside the clamp in order to push the insert out.
Repeat step 3, trim away a 1/16" or more on the side that held the treaded insert. This step may be skipped if you own a longer bolt with identical threads and diameter.
If needed, insert the appropriate layers of rubber spacers and then screw the clamp to the bell. Then trim the unsightly rubber of the sides of the clamp for a cleaner look
Now get out there and find your voice. Communicate with others as you take to the streets. Ding Ding Ding.