By Frank Dalleres Dame Sarah Storey cemented her legacy as Britain’s greatest Paralympic athlete by claiming a record-extending 18th gold medal – and then accused organisers of sexism. Storey, 46, won the women’s C5 cycling time trial in Paris on Wednesday for a fifth consecutive Games, 32 years after making her Paralympic debut as a swimmer at Barcelona 1992. She fought back from seven seconds behind at the halfway checkpoint to beat France’s Heidi Gaugain by four seconds on the 14.1km course. “I’m on top of the world. I came here to try and get the gold medal for the fifth time and I’ve done…