SIR CHRIS HOY is learning that motor racing is very different from cycling after a series of mechanical problems ended his challenge in round two of the European Le Mans Series at Imola yesterday.

The six-time Olympic champion and his teenage co-driver Charlie Robertson won the opening race of the season at Silverstone last month and were again quickest in Saturday practice and in qualifying yesterday.

The four-hour race proved a sterner test, though, and Hoy's Nissan dropped out after 108 laps following seven pitstops in all.

"It was tough out there," he explained. "A broken clutch cost us three laps, and two stop-and-go penalties put us back in fourth place. The gearbox casing then cracked, so the car is back in the garage and going nowhere. It wasn't our day today."

Hoy and Robertson now have a two-month break until the next race at the Red Bull Ring in Zeltweg, Austria.