HIGH petrol costs are forcing people to swap four wheels for two – fuelling a boom for traders in Coulsdon and Purley.

Commuters are ditching their cars in the face of rising train fares, insurance rates and fuel prices, according to traders.

Others are taking advantage of the unseasonably warm weather to get fit by cycling outside.

Paul Styles, co-director at Doble Motorcycles in Brighton Road, Coulsdon, said 2011 was on course to be the most profitable year since the company was set up 43 years ago.

"Winter is usually a slower time for us, but this year was particularly difficult with the very heavy snow and the recession," he said.

"But from January 1 it was like someone opened a door somewhere, and trade has been increasing ever since."

People new to motorbikes need to purchase safety equipment such as gloves, a helmet and a jacket, as well as buying the bike itself and paying for the test to get a licence.

"By the end of a year or 18 months that outlay has paid for itself in terms of what you save in petrol, or tax or rail tickets," said Mr Styles.

"The initial cost is a one-off and at the end of that period you've got this wonderful asset, rather than an empty wallet."

Small motorbikes can get 100 miles to a gallon of petrol, two to three times more than for an average car, and cost just £16 per year to tax.

Ray Wookey , who owns Cycling Made Easy in Chipstead Valley Road, Coulsdon, also said sales were rapidly increasing, with electric bicycles proving especially popular.

"The hills can put people off cycling to work because they don't want to arrive all sweaty," Mr Wookey said.

"An electric bike is the perfect antidote to that because you have the motor there to take the strain as much or as little as you like."

The batteries cost a few pence to charge and go for up to 30 miles.

The bikes do not need to be insured and the rider does not need a driving licence.

"Electric bikes are a bit more expensive, but our customers are telling us that petrol is becoming so prohibitively expensive that this is the canny thing to do," Mr Wookey added.