Fulcrum speed 55t tubular road wheelset cult the fulcrum speed 55t tubular road wheelset cult is the latest response to the historic challenge of headwinds and attrition fulcrum spent hours and hours in wind tunnels it studied the effects of rolling on the structure of the rim to make a wheel dedicated to the very essence of speed when average speeds are really high and every watt has to count the 3k carbon rim is 55mm high and features a wider 24 2mm external width the braking track has