Cyclists are being warned to beware of joy riders who are ‘borrowing’ their bikes for a day of fun.

Locking up your bicycle is not enough to protect it from thrill-seekers who take it for a ride before dumping it.

The offenders don’t want to sell the bike or even steal their parts, they just want to take them for a spin.

The bikes are then left undamaged against lamp posts around Brighton and Hove.

Stefan Petursson, who owns Amsterdammers bike shop in the Open Market, London Road, Brighton, said: “I went to pick one up at The Level after it was reported abandoned.

“Someone had tied a bit of mattress to it to try to carry a friend on it. It was obvious they just wanted it for a bit of fun as it was very battered but just neatly propped up against a lamp post.”

Bike shop owners say bike joy riding becomes more popular in the city once the sun starts shining as it offers people a quick and easy way of getting around.

Gordon Davey, owner of G-Whizz in Brunswick Street East, Hove, said he is often contacted by people who have spotted abandoned bikes.

Bike shop owners then form a network which circulates the details of the ditched bike.

Mr Petursson, who sells vintage Dutch bikes, keeps a list of all the frame models of the bikes he sells as well as the contact details of owners so he can reunite people with their bikes if they are taken.

The bikes also have an internal Dutch lock which means their wheels are frozen even if the bike lock is cut.

Mr Petursson said: “If you see a bike without a lock on please call us or the police. The longer it stands around the more likely it is it will be stolen again.”

Hundreds of bikes go missing from Brighton and Hove’s train stations every month.

On May 20 British Transport Police officers will be outside Brighton’s main station in Queens Road offering riders free electronic tags that will keep their bicycles safe.

PC Jerry Isterling said officers would be offering free electronic tagging devices called Immobitag. The tags ensure that stolen bikes are easier to identify and given back to their original owners if recovered.

Amsterdammers can be reached on 01273 571555 and Sussex Police’s number is 0845 6070999.

Argus reporter Naomi Loomes knows all bout bike joy riders as she was a victim.

“Having my bike taken by joy riders was incredibly annoying.

“It was locked to railings outside my house in Brighton as usual. When I left at about 9am it was there, but when I came back an hour later it was gone and the lock was on the floor.

“I immediately thought it had been stolen. I was angry and upset. One minute I had a bike, the next I didn’t.

“So when I got a call from Amsterdammers (where I bought the bike) that evening to say someone had seen it unlocked and propped up against railings in Hove and had handed it in to G-Whizz, I was relieved but puzzled.

“I can understand why it was taken, and I suppose looking back it’s quite funny, but it is really annoying.

“And with summer fast approaching, it will only get worse.”

If you have found a bike that may have been the victim of ‘joy riders’ email a picture of it with details to jo.wadsworth@theargus.co.uk and we will help to try to reunite you through our website, theargus.co.uk