Bike polo has a strong DIY ethic with people modifying just about any bike to play.
We recommend a sturdy bike with strong wheels and a low gear (38-45 gear inches is ideal). Some people play on fixed-gear bikes, but nowadays freewheels are taking over. Wheel-covers (often made from for-sale signs) are optional but they prevent excessive spoke breakage and protect a fragile wheel.
Birmingham Polo Bikes