In Thailand, thousands of cyclists have joined Crown Prince Maha Vajiralongkorn in a ride through Bangkok in honour of his mother, Queen Sirikit.Wearing shirts in the queen's colour – sky-blue – and emblazoned with "Bike for Mom", the cyclists paraded through streets closed to traffic. Many Thais outside the capital were expected to do the same. The queen – who turned 83 four days ago – is in very frail health, like the king, and will not be seen.Commentators say the mass event is the first to be publically led by the prince.King Bhumibol Adulyadej, 86, is the world's longest-reigning monarch. He has been on the throne in Thailand since 1946 and is widely revered. Reports said Organisers are also attempting to set a new world record for the greatest number of people cycling at once.