These wheels were tested shod with Continental GP4000 tyres. They are UCI/IPC compatible wheels suitable for road racing. At 58mm the rim is one of the deepest available for a handcycle. A very lightweight but rigid wheel they roll beautifilly and get up to speed quickly but as with any carbon rim they make a fair ammount of noise when they roll. Aesthetically the Zipp 404 wheels look great and very popular with the racing fraternity. The one drawback of this wheelset is that at around £1700 a set they are expensive.