Firstly i would find a relatively short event that you find easy. Personally i did this on the very first arcade event as it takes about one minute and is really easily as the computer cars will break unnecessarily on the easy corners giving you the chance to soar into the lead. The only thing to watch out for is whilst on the bike not been shunted by the computer. This happened to me and i fell off the bike on the last corner and lost. but i retried and got it straight away :) hope this helps