Big-hearted bikers are set to bring smiles to the faces of hundreds of sick children with a special toy run.

Up to 200 members of the Oxford UK chapter of the Harley Owners' Group will ride in convoy from the Harley-Davidson dealership in Wootton Road, Abingdon, to the children's cancer ward at the John Radcliffe Hospital, in Headington.

The bikers have spent weeks gathering gifts including teddy bears, crayons and colouring books in readiness for the toy run tomorrow.

It will be the eighth time the group has taken to the roads with large cuddly toys and other gifts strapped to the tanks of their motorcycles.

Oxford UK chapter director Pete Davies said: "It was an idea on the part of a chap called Ron Coles, who approached the hospital and asked if there was anything we could do to make the lives of the seriously ill kids there a little bit better."

Initially the ride was timed over Easter and the gifts were chocolate Easter eggs.

But the hospital suggested healthier items would be more helpful and said after Easter might be better as many children went home for the break where possible.

Mr Davies said: "It's very traumatic because you're dealing with very, very ill children.

"Us big hairy bikers are supposed to be tough guys, but when you see what some of those kids go through, it's quite heartbreaking.

"When we get there, a lot of them are gathering outside waiting, some of them are standing outside the windows. You can put a big smile on their faces just by turning up on a bunch of motorcycles."

At least 200 toys and gifts will be distributed after the convoy, which leaves at 11.30am.

For the first time since the event began they will not have a police escort, instead relying on 15 of its own marshals.

Mr Davies said: "We're exceptionally disappointed because the police have been extremely helpful in the past. We've been told they would have to produce a full-blown health and safety risk assessment and they don't have the budget to do that.

"We won't be able to ride in convoy through red lights and roundabouts. It will be fragmented rather than arriving as a group."

Sgt Steve Redding said: "The charity motorbike run was policed in the past out of goodwill, but we have had to reassess this in line with our new force policy. The police can only become involved in the control of traffic management for this type of event if there is a formal road closure, as without this we have no legislative powers to assist.

"Many people believe it is the police's responsibility to ensure safety at public events; in fact it is the event organisers' responsibility and the bike run is no exception.

"We wish them well in their excellent cause, indeed police staff are taking part, and we hope it goes well."