A Hampstead dad is appealing for help to get his missing one-of-a-kind bike back after it was stolen over the Bank Holiday weekend.

James Hamm, 35, bought the Cervelo bike - once ridden by 2008 Tour De France champion Carlos Sastre - from the Spanish cyclist's charity Smilekers in 2014.

Ham & High: James out for a ride on his Cervelo bike - it formerly belonged to Tour De France winner Carlos SastreJames out for a ride on his Cervelo bike - it formerly belonged to Tour De France winner Carlos Sastre (Image: James Hamm)

But the irreplaceable bike was stolen from outside of James' Fitzjohn's Avenue home on Sunday May 30 - and he's now said he'd offer a £250 reward for the bike's return, with the same amount going to Smilekers as a donation.

He told this newspaper: "We'll see where this ends up - I've obviously alerted the police but I think there's a good chance I don't get it back.

Ham & High: Carlos Sastre won the 2008 Tour on a similar bike to the one stolen from James HammCarlos Sastre won the 2008 Tour on a similar bike to the one stolen from James Hamm (Image: Bjarte Hetland)

"The bike was an intro to cycling for me, taking me 75,000km exploring the UK, and the loss is much more personal than I'd imagined it would be.

"I feel very safe around my flat because of all the trees and green, it feels like a safe community so it's easy to let your guard down and forget you're still in a big city with sophisticated thieves."

The bike was stolen in the early evening on May 30, and James added that the manner of the theft was worrying.

Ham & High: James Hamm's stolen Cervelo S5 - once owned by a Tour de France winnerJames Hamm's stolen Cervelo S5 - once owned by a Tour de France winner (Image: James Hamm)

He said: "There wasn't any sign of damage to the lock which means they had the ability to pick the lock. The thieves must have been going up and down the street with tools handy because they picked a Thule bike lock and stole my bike while I was taking a dinner break."

The bike is a grey and white Cervelo S5 VWD model. James has reported it to the police and it is registered on the Immobilise stolen property database - but the Met Police has told James it's unlikely to be able to recover the bike without more information coming to light.

James added: "It was worth more to me than to anybody else. it's a bike which had a big story to tell."

If you spot James' bike, contact the Ham&High newsdesk on Sam.Volpe@Archant.co.uk to pass on any information that might help him get it back.