A woman preparing for a charity cycle challenge vowed this week to carry on with her efforts after 'idiots' stole her bike after a collision.

Viki Barton, 24, from Longham, was riding her blue and silver Apollo Excel mountain bike near Brisley between 6pm and 6.10pm on Tuesday, July 10 when it happened. She said she was about half a mile from the village in Fludge's Lane when a mystery vehicle knocked her off her bike.

Miss Barton, who is preparing to ride from John O'Groats to Land's End in September, said: 'I remember hearing a car behind me so I pulled up on the verge, and remember thinking: 'It is taking a long time for this car to come past me.' I started to look around and saw something out of the corner of my eye and that was it. It is a big blur.'

She was knocked unconscious, and when she came round on the verge her bike was gone. She does not know who stole it, and there were no witnesses.

Miss Barton suffered broken ribs, a split lip and a black eye and went to the Norfolk and Norwich University Hospital after she rang her friend from Brisley.

She said: 'It is a bit of a shock. It is pretty low to hit me in the first place as well as take my bike. I'm more determined to do the bike ride. Why should someone's mindless actions stop me doing it? And why should the charities miss out because some idiots knocked me off and stole my bike.'

She hopes to start the long ride on September 10 in aid of the Swanton Morley-based Light Dragoons' Colonel's Appeal, which supports dragoons wounded in action, their families and those of servicemen killed on duty. Miss Barton also wants to raise funds for the Matthew Project, which supports people with drug and alcohol problems in Norfolk and Suffolk.

The stolen bike, designed for a man, has dual suspension, 18 gears and a seat cover. Information about the theft to PC Marcus Wall at Dereham on 101.

To sponsor Miss Barton visit www.virginmoneygiving.com/VikiBarton