If I'm going thru somewhere busy I use a whistle that I've got hanging off my helmet strap. People definitely hear you. Generally jumping out their skin. The only other people on the road with them tend to be motocops. Otherwise Oi! Did really enjoy the bell when was borrowing GFs bike which had one. Seems quite polite. Most just ignore/don't hear tho.
If I'm going thru somewhere busy I use a whistle that I've got hanging off my helmet strap. People definitely hear you. Generally jumping out their skin. The only other people on the road with them tend to be motocops. Otherwise Oi! Did really enjoy the bell when was borrowing GFs bike which had one. Seems quite polite. Most just ignore/don't hear tho.