A U.S. company has agreed to test tire configurations on the 21-passenger buses used by New Brunswick schools following complaints about their safety from three mothers whose sons were killed in the Bathurst van crash.

Ana Acevedo, Isabelle Hains and Marcella Kelly said they found out in October that the buses that are currently used to transport students from Bathurst High School have winter tires in the rear but ribbed, all-season tires in the front.

The mothers believe the mixed configuration of tires is unsafe. John Malher, who writes a column on tires for the Toronto Star, agrees. He said he has talked with large tire companies about mixing and matching tires and the responses from experts have been similar.

"That setup is basically unsafe," Malher said. "It allows you traction to move the vehicle forward, but it doesn't give you traction for braking or turning."

Javier Acevedo, Daniel Hains and Nicholas Kelly were among the seven members of the Bathurst High School boys basketball team killed in January 2008 when their 15-passenger van slid into the path of a transport truck. The wife of the team's coach was also killed.

Investigators found that the vehicle's brakes were faulty, the body was rusty and its tires were worn.

New Brunswick's Department of Education subsequently banned the use of the 15-passenger vans and replaced them with 21-passenger school buses.

Acevedo said she's frustrated that the department is using vehicles that she believes are unsafe.

"What bugs me the most, because they robbed me of everything, and here we are now telling them this is not safe to travel," she said. "It is not safe to transport children like that."

The mothers said Continental Tires, which has its North American automotive systems headquarters in Michigan, has agreed to conduct tests on a 21-passenger bus with various tire configurations.

However, the company does not have a vehicle in its test fleet that matches the specifications of the buses used in Bathurst, so the mothers approached the Department of Education to see whether it could loan Continental such a bus.

No loan decision until January

A department spokesperson said no decision will be made about the loan until January.

"They are not doing anything about this," Acevedo said. "What are you waiting for? Another tragedy? Then, what are you going to say?"

Acevedo, Hains and Kelly have drafted a letter to newspapers across the country appealing to anyone who has a bus with the same specifications as those used in Bathurst to come forward and could lend it to the company so it can be tested.

Meanwhile, officials from the province have told the mothers that the 21-passenger bus has a low accident rate when using the configuration of winter tires in the back and all-season tires on the front.

A spokesperson for the province said it consulted its own experts on the matter and found at least two sources who say the tire configuration is appropriate.

Hains said the mothers will not give up the fight because many parents are worried about the safety issue.

"I have to say we have so many supporters," Hains said. "I call them an army of angels.

"I think this is why we keep going, because people want us to have safe travel for the children, and I feel we are our children's voice. This is what keeps us going to have these changes."