An off-road motorcyclist died during a forest race in an “entirely avoidable” tragedy caused by a weak component in his bike, an inquest heard.

A university expert believed that the makers of the off-road motorcycle had used the wrong aluminium alloy in the headstock.

This was in a report by Dr Iain Fielden, a research consultant at Sheffield Hallam University.

At a resumed inquest at Caernarfon, coroner Dewi Pritchard Jones said the report had been sent to the makers, X-Trig of Germany but there had been no response.

He recorded a conclusion of accidental death on 43-year-old Ross Hall of Huncoat, Accrington.

Mr Hall had been suffocated by mud when he fell from his machine during time trials at Cefn Llwyd, a remote private forest near Bala in November 2015.

The inquest was told his machine may have hit a tree, although it was not known whether he was still mounted.

He had face and neck injuries but no fractures which the coroner said indicated that speed was not a factor.

Mr Pritchard Jones said: "Dr Fielden has in my view produced a report which is very relevant to everybody who is involved in off-road biking. It highlights weakness generally but also in the headstock that was in use in this instance.”

He added :”I hope other motorcyclists will be aware of the potential danger and that the Driver and Vehicle Standards Agency and trading standards will be told in this country.”

It was an entirely avoidable incident because had a different headstock been used it would not have happened.

The coroner said a microscopic crack had in his view led to a complete fracture. The rider may not have known exactly what happened because although the headstock had completely fractured other parts would be in their normal place.

Mr Pritchard Jones said the alloy used was prone to corrosive cracking. “Other alloys and metals should be used,” he urged. Normally he would be sending a prevention of deaths notice to the manufacturers but because they were in Germany and outside his jurisdiction this could not be done.

Mr Hall was found dead after an “Extreme Team Enduro” three-hour race around seven-and-a-half-mile laps in Cefn Llwyd private forest.