Are fibreglass tanks actually legal?

[SumpMagnet]

Was having this discussion as a follow on to the great E10 debate.

A friend was thinking of buying one for his old school 60's cafe racer, to replace a rather tatty old original one. He has had issues with rust, and sealed it.....but is now worried about E10 eating the liner material. Personally...I think he's bonkers to fit one these days.... but the question I couldn;t find an answer to is whether its actually legal.

There are plastic tanks on bikes, and I have had bikes with them....but fibreglass never seems to do well in a crash. It cracks and shatters rather than denting.
Then, of course, there is the effect of Ethanol on the resin. Unless you seal it...the resin is going to get dissolved.

so. Given the risk of the resin turning to goop in your carbs and the tank leaking..or splitting in a crash and rurning your pride and joy into charcoal.... are they road legal, and how does it go with insurance companies?

[Laverdaroo]

I was under the impression you could have a fibreglass cover but tanks weren't legal for the reasons stated. I dont see why you'd want one to be honest, nothing but hassle.......again, for the reasons you stated. Talk him out of it!!

[Bryanj]

They are legal on certain age bikes, plastic wasnt but now is

[McCabe-Thiele (Ted)]

https://www.motorcyclelawscotland.co.uk/why-choose-us/legal-information-centre/fuel-tanks/

I would not use one as per reasons given above -the regulations shown in the link relate to UK law not just Scotland if you click further into the links you will see reference to other amendments originally via EU legislation. Cars have been using plastic for about 20 years I think.

[SumpMagnet]

cool ..... the bike in question is an 80's machine....so the motorcycle law page says it is illegal.

Worryingly, the 1993 law change doesn;t seem to specify what materials can ... or should ... be used for a petrol tank. I guess this is to allow for plastics being used in petrol tanks, but at least a major manufacturer will have suitable tested the materials used. The guys making up fibreglass mouldings are probably not doing much testing.

I will show him the legal page....and talk him out of it if I can. I guess he could take a smaller tank...and use a fibreglass one as a cover...but...thats more hassle too especially when its time to fill up.

He should go get himself a proper alloy tank if he wants the look. I would if I was about £1000 richer than I am right now!

[MrDavo]

While I’m not condoning their use, or suggesting your mate should use one, when I was Classic racing I was putting blue Avgas 100LL (I queued up at a local airport with my Jerry cans) into the fibreglass tank on my Triton with no problems whatsoever, despite occasional crash testing.

I got the last laugh at Ty Croes, where I found a fellow racer who told me I was wasting my money, peering down the hole in his piston crown.

[SumpMagnet]

I got this wierd vision of a long queue of cafe racers etc. all lining up on the slip road approach to Heathrow with jerry-cans bungeed to the back......

Just don't mix up Avgas with jet fuel...

[Arch stanton]

A mate of mine built a race replica, using s new grp tank. He left E5 petrol in the tank over winter. It was a mass of blisters up to the fuel line.
Tank ruined. E10 can only be worse.

[MrDavo]

The queuing up for Avgas was rather bizarre, me in my old Mercedes estate, in the queue for the pump behind a couple of Cessnas. I won’t name the airport as selling me the fuel at all, without an aeroplane in sight, was of dubious legality, and maybe they still do it.

No problem with the road tax element as I was going racing, but I think the understanding was that I was taking the Avgas away to put into my light aircraft.

[MrDavo]