Underseat fuel tanks?

[Jono]

Was just wondering if and how much underseat fuel tanks change the way a bike performs and handles. I really have no idea.

Was thinking about it today after i saw the Suzuki GSXF250 Across that has a helmet compartment where the fuel tank would normally be and the fuel tank under the seat.

Cheers

[Roj]

Was just wondering if and how much underseat fuel tanks change the way a bike performs and handles. I really have no idea.

Was thinking about it today after i saw the Suzuki GSXF250 Across that has a helmet compartment where the fuel tank would normally be and the fuel tank under the seat.

Cheers

It can drop the centre of gravity of the bike, if you are really pushing a bike hard this can make a difference, but in general terms a 250 is usually riden by learners so they are unlikely to be pushing it that hard..., the helmet compartment is a good idea though

[vifferman]

It's all about "mass centralisation" these days.
There was a trend a while back to get the weight as low as possible, but it was discovered that this actually made bikes more difficult to steer. Now bikes are being designed so that the biggest mass on the bike (the rider) and the second biggest (engine/gearbox) are as close to the centre of the bike as possible.
Bikes with high-up, heavy donks (like the Buell) also don't have the gas tank in the 'conventional' location: the gas is in the frame, and the oil tank is in the swingarm. Other bikes like the new "repli-racers" tend to have shorter gearboxes in order to get the engine/gearbox lump as compact as possible, so it can be positioned more easily in the best position for the ideal COG.

Blah blah blah...

[Mully]

Bikes with high-up, heavy donks (like the Buell) also don't have the gas tank in the 'conventional' location: the gas is in the frame, and the oil tank is in the swingarm.

I've always wondered what happened if you binned a Buell and damaged the frame/swingarm. I assume they'd have to pressure test the repair??