Modern Vespa

Hi all

Thought I'd post an idea I've been toying with recently, hopefully there is an obvious flaw that I haven't considered and/or someone has done before.

Basically I was thinking of creating a custom tank that would fit my Rally 200 and greatly extend range/capacity.

I've looked at extended tanks that go further into the body which extend capacity to 11/12 litres but also require a fuel pump etc.

My idea is to go the opposite way and have a tank fabricated that is basically the size of a Rally seat which is grafted onto a standard PX tank (with it's top cut open), creating a single tank of about 20 litres (60cm x 24cm x 12cm should give about 12 litres).

Basically an enlarged version of the PLC Corse tanks - https://www.scooter-center.com/en/fuel-tank-seat-plc-corse-grp-classic-vespa-v50-pv-125-et3-7676520

I'd then have a seat made in gel/foam of about 10mm thick which should be reasonaly comfortable if designed right (kind of like a modern motorbike seat is).

Apart from being a bit of a project and adding a bit of weight (both tank and exta fuel) are there any reasons this is a terrible idea?

I'd guess there will be internal baffles/struts to give strength (without too much extra weight) and stop the fuel slooshing about too much.

For the filling cap will use a flushmount Newton Equipment - https://www.newton-equipment.com/aero-range.html (or similar) with a cutout in the seat (like a Lambretta). Might even replace the fuel tap with a simpler fitting so no need to access inside on tank to replace the fuel tap etc (though should be possible with a longer version of the tool).

How could this go wrong

Cheers

As you linked, you can buy commercial products that do the same thing. If you have the skills and don't mind doing the work, I see nothing wrong with doing it.

You'll be adding a tiny bit of head pressure when the tank is full, but nothing that would overcome the carb float.

If you build it, keep the thread updated and take lots of pictures.

Thanks Chandlerman, encouraging to hear.

Will post my progress.

My hesitation on having a fuel tank with a similar design as the PLC would be ergonomics. It might be uncomfortable to ride around in a seat where you can't really move your behind forward or backward very much. I know it would be for me!

I like the aesthetics of the fuel tank cap, but because of the way they're designed, you won't be able to fill the tank as full as it could be. Welding in a piaggo PX fuel filler neck would gain you the most fluid volume.

If you aren't fabricating the fuel tank up yourself, i'm guessing it could cost you in the neighborhood of $1000 to get someone to build it for you.

I'd recommend to take a second look at any of the long range tanks that are currently available...such as the Scooter Trumps long range tank. Yes it uses a fuel pump AND you loose out on having an oil reservoir, but it will be a bolt on affair.

Yo,

Agree that more range would be better and carrying extra in a can sucks. I'd be happy with just a few more litres though and keeping the autolube by looking to make the tank a bit higher but still fit under the standard PX seat.

Trips here take longer by Vespa (than car or motorcycle) not because you can't hold open road speeds (100kmph max speed limit), and keep up with traffic, but because of not being able to "leapfrog" gas stations in rural situations. Pretty much topping up every hour or so. A bit of a buffer would be nice so you don't have to stop as often.

Besides the extra weight I'd consider that 20L might outrun the autolube and I'd want a breather well before then anyway. Best I've achieved on a standard 7L tank on the open road is just over 200 kilometres (Pinasco 225 with SIP 2).

10L would probably allow not having to carry extra fuel 99% of the time. This is for New Zealand conditions where State Highways are often more like B roads elsewhere.

Chur