The rider of an Aprilia Tuono superbike, caught speeding at Selside, questioned the speed recorded by police.
Ian Ferrier, 46, told Skipton magistrates he did not deny speeding on August 18 on the B6479, but believed he had not been doing 88mph, as recorded by police.
Ferrier, who had previously admitted speeding by letter to court, but who was asked to attend to confirm his plea, said he had been directly behind a friend at the time.
He said his friend had also been charged with speeding, but at 73mph, and had been dealt with by going on a speed awareness course.
Ferrier, of Wallhurst Close, Worsthorne, Burnley, had his licence endorsed with four penalty points and was fined £200. He was ordered to pay a £20 victims surcharge, but magistrates made no order for costs.