The Bristol 450 made its race debut at the 1953 24 Hours of Le Mans race. Two cars were entered, with a third held back as a spare. Unfortunately for Bristol, both were out before half distance with near-identical failures. In each case the balance weights became detached from the crankshaft. This caused the rear wheels to lock at high speed, in turn causing the cars to veer off the road and catch fire. However, in the laps that the cars had managed to complete, Jack Fairman easily managed to post a new lap record for the 2 litre class. The cars were rebuilt at the factory, incorporating the revised aerodynamic bodywork, and only three weeks later, in early July, were entered into the 12h race at Reims. The Reims track shared the high speed character of its French cousin at La Sarthe and suited the Bristol's character well. Although one car again broke down, this time due to transmission failure on the first lap, the remaining car cruised to a class victory and finished fifth overall.