They were cycling to raise money for the burns unit at The Children's Hospital, Westmead.

The group said the pain they suffered was minimal compared with what children in the burns unit went through.

The group hopes to raise $50,000 by next month to provide a full-time anaesthetist and help build family-friendly wards and recovery areas.

Heathcote resident and station officer Brad Lewis said raising money through the "400 in 4" Charity Ride was a very personal thing for a lot of firefighters. "We see the outcome of fires, we see the kids and the extent of their injuries," Mr Lewis said.

"We have so much to do with it and it is something very close to our hearts." The group left Sydney on May 3 and punctured 16 tyres before they arrived at Wagga fire station on May 6.

"We are not a group of cyclists that happen to be firefighters, but firefighters that are cycling for the injured children," Mr Lewis said.

The first ride was held six years ago and was organised by Scott Hanley, of Gymea, and Mark Edis, of Wagga Wagga. Former Olympic mountain bike rider Rob Woods, of Miranda, rode the gruelling distance with his co-workers.

Donations: "400 in 4" Charity Ride, visit 400in4.org.