Van Dyk was well positioned to win the race, but was forced to brake too soon in the final 500m and was not able to hold off Paralympian gold medallist, Alessandro Zanardi's last minute attack.
The race went to a sprint finish over the last 100m, but the distance was just too short for Van Dyk to recover the situation.
Van Dyk was nevertheless satisfied with the two silver medals he claimed at the 2013 World Championships, despite losing his World Champion status.
Meanwhile, George Rex, who competes as a T1 tricyclist, was involved in a closely contested race between the Spanish World Champion and a young Czech rider.
Playing to his competitive strengths as a climber, Rex attacked on the last lap of the race and held onto the lead for much of the time.
However, the technical nature of the circuit was ultimately too much for him and he had to settle for 3rd place.