Report Fibreglass Fuel Tanks in Montesa Posted March 9, 2021 On 3/5/2021 at 6:18 PM, woody said: You won't get turned away from any trial for having a fibreglass tank. There are new fibreglass tanks still being made and being used on plenty of bikes The law was introduced in 1973 following a road accident when a fibreglass tank spit and caused a fire. Hence all UK trials bikes had an alloy tank from then on to replace the original factory glass tank. It's never been clear as to whether the law was for all bikes or just those registered for the road, but as most trials were road based back then I think they all had their tanks swapped for alloy versions at import. It only applied to fibreglass tanks, doubtful there were any plastic tanks at that time. 1980s bikes were used on the road with their original plastic tanks Thanks for the info. I've decided to keep one bike with the fibreglass tank as it has now and the other with the Ally tank..