The new Volvo FMX is raising the bar on ground clearance. Stray branches and flying rocks are no longer the threat they used to be.
The people who have been testing the new truck with air suspension say it will be indispensable – in Russian forests, South African quarries or any construction site you come across.
The only things hanging down are the wheels
300 millimetres above ground
Previously, air suspension has been known for having too little ground clearance to have any widespread use in construction. But the new rear air suspension is about to change that (see separate article on page 24). Its new design puts vulnerable parts such as spring members and air bellows higher up – above the drive axles – where they are less exposed.
“This results in at least 300 millimetres of ground clearance and the suspension is no longer in the line of fire for rocks and stones,” says product planner Bosse Franzon and continues. “The disc brakes are now protected by safety cages – but even these are 340 millimetres above the ground. Now the only things hanging down are the wheels.”
Truck appearances can be deceptive
One of the people responsible for the new chassis is Jonas Odermalm. He points out that with ground clearance, what you see is not always what you get: “Sometimes the front of a truck might appear to be high but leaves engine components exposed just beyond the bumper. Some might have a plastic cover to protect them, but this is pointless. The Volvo FMX, on the other hand, has a very strong protection plate to protect the radiator and other vital parts.”
The belly line
A completely new driven front axle also plays an important role in ground clearance. This has been moved 100 millimetres further forward to improve the approach angle. And its lowest part, the parallel rod, is now protected behind the front axle housing.
“Of course, between the axles we have all the chassis components, but these have always been located higher up on a Volvo,” says Bosse Franzon. “If you look at the profile from behind the truck, you can see the belly line is streamlined – this helps to avoid getting stuck over uneven surfaces,” he adds.
Sticks and stones
The oil sump guard that protects the underside of the front is not new, but unique to the trucking industry. “This is a real skid-plate, designed to resist up to four and half tonnes of impact from an object the size of your fist,” says Jonas Odermalm. It creates a flat surface from bumper to axle and protects the radiator and engine components from sticks and stones. “Also, if you run into a pile of sand and then reverse out again, it won’t fill up like a Swedish cheese slicer,” says Bosse Franzon, with a grin on his face.
Read more about the rear air suspension for construction trucks