Knog Oi Classic Bell - Small Bike bells generally look & sound a bit ugly. But why? What if they looked sexy & sounded like an angel playing the glockenspiel? A bell with a beautiful tone, but also a remarkable style and choice of materials that embody a rider?ÇÖs personality. Knog wanted to embrace a variety of riding genres, without compromising any. The Oi fits almost all cylindrical bars. The Small Oi fits 22.2mm bars e.g Mountain bike (near the grips), BMX & some old commuters.