Police have identified an increasing risk on the road from affluent middle-aged men attempting to recapture their lost youth by riding powerful motorbikes . Nicknamed « Bambis « by traffic police --- born again middle-aged bikers --- they have inspired the Association of Chief Police Officers to launch a campaign to encourage bike dealers to ensure that their middle-aged customers get the training they need to meet the challenge that newer bikes pose . “ Many of them used to ride bikes years ago but they don't seem to realise that bikes have advanced so much over the past 20 years that today's machines bear little resemblance to what they were used to “ said Chief Insp. David Short of North Yorkshire traffic police , whose research led to the current campaign . “ They return to biking with a little more money in their pockets and buy bikes that are actually very similar to performance bikes used in racing . They simply go too fast , lose control and hit something “ . Many of the older riders obtained their licenses 30 years ago and , having driven comfortably for years in cars , are not used to riding powerful motorbikes in today's busy road conditions . In London the return to bikes is spearheaded* by businessmen who , tired of being stuck in traffic or using public transport , turn to fashionable high-speed motorbikes which can cost as much as £ 15,000 . Dodging* jams and using side-alleys , however , is far more hazardous to the middle-aged motorist than sitting for a few minutes in an urban traffic queue. Bikes make up 10 per cent of all traffic in the capital , compared to just one per cent nationally . Insurers have also identified the group and believe that many older bikers are returning after raising a family . The trend has only become apparent over the last few years and the statistics are now beginning to influence increases in insurance premiums . The trend towards older men riding bikes in rural areas was first spotted by