Fibreglass VS Alloy Oil tank

Morgy · Oct 23, 2019

Apart from aesthetics any benefits to glass fibre oil tanks over the Alloy ones?

Fast Eddie · Oct 23, 2019

What?

No brainer mate. Alloy splits and dumps it’s contents on the road / track and your rear tire.

Fibre glass doesn’t. Simple as that really.

Of course, you could substitute fibre glass for exposed weave carbon fibre. Yeah, got you thinking now right ?!?

Triton Thrasher · Oct 23, 2019

My alloy Manx tank developed ten separate cracks.

Morgy · Oct 23, 2019

Triton Thrasher said:
My alloy Manx tank developed ten separate cracks.

Bloody hell!!

Fast Eddie said:
Alloy splits and dumps it’s contents on the road / track and your rear tire.

Fibre glass doesn’t. Simple as that really.

you could substitute fibre glass for exposed weave carbon fibre.

Is it all the Oil tanks in general or just cheaper versions?

Triton Thrasher · Oct 23, 2019

Morgy said:
Bloody hell!!

Sorry I missed the bit about it being an oil tank query.

My problems were with a petrol tank.

Fast Eddie · Oct 23, 2019

Degens has perfected mounting alloy petrol tanks. No need to worry about those and, as we know, fibre glass petrol tanks aren’t flavour of the month.

Good alloy oil tanks made by someone like Degens will be better than some cheap anonymous eBay / auto jumble shite. But still a potential weakness.

Fibre glass is the way to go for an oil tank IMHO.

What was Dave’s advice?

Morgy · Oct 23, 2019

Fast Eddie said:
Degens has perfected mounting alloy petrol tanks. No need to worry about those and, as we know, fibre glass petrol tanks aren’t flavour of the month.

Good alloy oil tanks made by someone like Degens will be better than some cheap anonymous eBay / auto jumble shite. But still a potential weakness.

Fibre glass is the way to go for an oil tank IMHO.

What was Dave’s advice?

He did mention about using Exhaust mounts under the fuel tank to fix on to the frame, Something i had been thinking about when i looked at a custom triton online as i didn't have the normal tank strap.

I am a sucker for chrome and polished ally and dave did mention they fail but i didn't ask the cause or if it was just in a race situation rather than normal road uses, Having seen a firbe oil tank with battery on the front that looked hideous i was looking for other options

Fast Eddie · Oct 23, 2019

IMHO a black oil tank looks fine, it’s central in the bike and is kinda ‘hidden’ there.

If you’re set on polished alloy then go for it. Dave will make one (at least I assume he still does) and knows where and how to strengthen them.

You’re not racing it, and so long as you’re not doing 8,000rpm everywhere you’ll be fine. If you are doing 8,000rpm everywhere you’ll have other things to worry about anyway...

Adam_R · Oct 23, 2019

Fast Eddie said:
Of course, you could substitute fibre glass for exposed weave carbon fibre. Yeah, got you thinking now right ?!?

Yeah, you have got me thinking!, certainly would be different

Fast Eddie · Oct 23, 2019

I did the exposed carbon thing with the oil tank, seat, front mudguard on this racer. Always thought it looked cool and would look super cool on a cafe racer!

Triton Thrasher · Oct 23, 2019

Fast Eddie said:
Degens has perfected mounting alloy petrol tanks. No need to worry about those and, as we know, fibre glass petrol tanks aren’t flavour of the month.

Good alloy oil tanks made by someone like Degens will be better than some cheap anonymous eBay / auto jumble shite. But still a potential weakness.

Fibre glass is the way to go for an oil tank IMHO.

What was Dave’s advice?

The alloy tank had to last a seven lap TT. Mount it any way you like but eventually it will crack in road use.

Fast Eddie · Oct 23, 2019

Triton Thrasher said:
The alloy tank had to last a seven lap TT. Mount it any way you like but eventually it will crack in road use.

Probably true. Degens method is very different to the Manxes though. No pipe lagging etc in sight!

Many featherbed alloy petrol tanks are really badly mounted IMHO and often people’s efforts make it worse. Like the pipe lagging, yes it’s soft, but there’s little actual support. So when the strap is clamped / tightened it can effectively try to spread the tank, putting it under stress, and as we all know, stress+vibration=fracture !

Oil tanks are more likely to crack in my experience, but they seldom let go completely and the hair line cracks can usually be spotted before it gets to the ‘let go’ stage.

Triton Thrasher · Oct 23, 2019

That plumber’s insulation stuff flattens and wears through.

I’ve got Dresda clipons and they’re good gear and I’ve had advice from them too, but DD ain’t St Francis of Assisi.

Fast Eddie · Oct 23, 2019

Indeed. Perhaps not.

jbruney · Oct 23, 2019

That carbon fiber sure looks good on there. I wish I knew how to work the stuff because I find it interesting.

I see the mudguard too FE. Very nice.... I also like the rest of the bike.

ashman · Oct 24, 2019

10 years ago I brought a round 3 ltr oil tank from Low Brows and it mounted under my tool tray on the Wideline, it is super light and I have 2 mounting bolts at the top of the tank rubber mounted of course and a breather bolt in the middle of the two mounting bolt and one middle mounting bracket on the bottom mounted to my bottom rear guard mount rubber mounted on the oil tank, the oil tank holds 2 ltr of oil and one ltr for air curculation I also run a Lochard oil cooler up front, when riding hard as normal for me I can hold my hand on the oil tank and its very cool to touch, so far after 10 years running it have had no problems at all, no cracks and it looks so nice where its mounted the filler cap is to the top side so no need to remover the seat to check the oil.
The round oil tank is spun machined and the two ends piece is welded in the middle of the tank and the ends are dome shaped this tank looks so nice on my Wideline and I think I only paid $130 for it.

Ashley

Chris · Oct 25, 2019

Hi
My original triton had the small parralellogram tank in alloy. Not much capacity & no battery holder on the front.
Table underneath with very thick rubber wc flush pipe connectors cut in half.
( used these on the petrol tank as well)
Top mount was a tube through the tank the through stud had petrol pipe as insulation. Two Hoover straps mounted to bobbins on the side of the tank held it loosly to the frame tubes. Cap was an oil can internal thread job.
I never had a problem with this tank but by then had started to use oil tanks with much larger capacity on all my bikes.
I gave it to my friend John to use in his sprint Atlas after 2 seasons in his bike it was cracked everywhere. It's all about the mounting but eventually alloy will fall.
Two repairs on my race bike. Side mount threads pulled. Converted to tube. Petrol cap leak. The neck was not welded to to the throat of the tank but glued.

Does anyone remember the Harris frame with the overbored Armstrong four stroke single engine? He encased his oil tank in a foam box that was bungeed to the frame? No mounts just connectors. Only way to stop the tank cracking.