Automotive News Canada - September 2022 - 30

30
* SEPTEMBER 2022
It just might be the
most important piece
of automotive hardware
created this century
By RICHARD TRUETT
AUTOMOTIVE NEWS
THE WAY CHRIS BORRONI-BIRD SEES
it, the skateboard chassis - the architecture
that underpins most of today's battery-electric
vehicles - would have been
invented by someone else if General Motors
hadn't done it first two decades ago.
" When you think about a ground-up
design for an electric vehicle, the skateboard
is the obvious choice, the obvious
solution, " Borroni-Bird, GM's former
director of advanced technology vehicle
concepts, said.
" You lower the centre of gravity,
improve road-holding, have more freedom
in design, you get better crash protection
for the front of the vehicle, and there's
more storage, so it creates a lot of benefits. "
The skateboard chassis is a significant
creation. Key to making EVs viable, it has
also opened a door for dozens of startups
looking to seize the opportunity.
" There's no doubt the move to electrification
has taken massive barriers to
entry out of the automotive business, "
said Greg Fraker, president of engineering
services at Detroit's Roush Industries.
" The business of fossil fuels, internal
combustion engines, managing the emissions
and certifications - those are very
mature industries
that require massive
investments.
Electrification and
the skateboard are
the great equalizers.
They allow a lot
of startups a better
cost advantage to get
involved. "
Borroni-Bird:
" The skateboard
is the obvious
choice. "
FILE PHOTO
Borroni-Bird's
team, empowered by
former GM R&D chief
Larry Burns, created
the AUTOnomy skateboard
concept, which
debuted at the 2002
North American International Auto Show
in Detroit.
That first design was not for BEVs,
however. GM's vision was for a hydrogen
fuel cell and drive-by-wire technology,
all of which was packaged in the 15-centimetre-thick
chassis. Later, a skateboard
would underpin GM's fully driveable
Hy-Wire hydrogen concept car.
DESIGNED FOR ENERGY EFFICIENCY
Changes to automobile chassis are
extremely rare. For at least the last six
decades, passenger vehicles were built
one of two ways: with the body mounted
on a separate frame - usually made of
steel - or with the body and frame integrated
as one, commonly known as unibody.
Body-on-frame
and unibody architectures
were designed to package transmissions,
radiators, exhaust systems, fuel
tanks and other components not used in
EVs. Early EVs converted from internal-combustion-engine
vehicles had traditional
body-on-frame or unibody chassis,
such as the now-discontinued Toyota
RAV4 EV, Chevrolet S-10 Electric and
Ford Focus Electric. They performed reasonably
well but had short driving ranges
in part because the batteries were placed
wherever there was space.
Even GM's EV1, which was designed
from the ground up as an electric vehicle,
placed the batteries in a T-shaped structure
that ran down the centre of the car
and struggled to get more than 160 kilometres
between charges. Those same cars
would have longer driving ranges with
today's better batteries.
With a skateboard chassis, the battery
pack is wide and long and placed below the
floor. It usually runs from under the forAUTOMOTIVE
NEWS
ILLUSTRATION
THE EV SKATEBOARD:
THE INNOVATION REDEFINING THE INDUSTRY
THE SKATEBOARD
* History: General Motors developed
the skateboard chassis to carry a
hydrogen-powered fuel cell and driveby-wire
technology. The AUTOnomy,
a chassis that contained the fuel cell
stack and hydrogen storage tank, and
motors in each wheel, debuted at the
2002 North American International
Auto Show.
* Today: Underpins most batteryelectric
vehicles
* Advantages: Low centre of gravity
improves handling; dedicated space
for battery pack in the floor creates
more interior room; easier for
designers to add different body styles;
all-wheel drive is easily added; electric
motors can be placed in the front or
rear axles, or both
* Disadvantages: Reduced towing
and hauling capability; not as capable
off-road; repair costs; accessibility of
battery cells
ward dash to the aft edge of the rear seat/
trunk area and is a structural part of the
vehicle.
" Once you decide you are going to
make battery-electric vehicles at scale, the
arguments in favour of a ground-up vehicle
design are compelling. You get much
better performance and better range, and
it is far more likely to sell than a compromised
vehicle based on last century's
vehicle architectures, " said Borroni-Bird.
TAKING SHAPE
Other automakers before GM made
bodies with integrated floors. The classic
Volkswagen Beetle, for instance, had the
car's stamped floorpans welded into the
frame in a layout VW called " body on pan. "
In the 1990s, Mercedes-Benz's A-Class subcompact
had a flat floor. But neither car
housed any of the vehicle's powertrain components
or electronics in the floor.
The genesis of the skateboard chassis,
Borroni-Bird said, is rooted in a blending
of the A-Class and the Opel Filo concept
car shown at the 2001 Geneva auto show.
The Filo, created by Italian design house
Bertone and Sweden-based bearings supplier
SKF, featured drive-by-wire technology
and had a flat floor. The steering
wheel could slide across the width of the
dash so the driver could sit anywhere in
the front.
At the turn of the century, GM was
investing billions of dollars in developing
hydrogen fuel cells, a technology -
still under development at the automaker
today - that could solve two problems:
driving range and emissions.
Borroni-Bird said GM's original skateboard
was envisioned to accommodate not
only the fuel cell and drive-by-wire technology
the company was developing, but an
electric motor at each wheel. Though GM
invented the skateboard, other automakers
put it into mass production first. GM's EV
plans were derailed by financial issues and
other problems. Nissan, with the 2010 Leaf,
and Tesla, with the 2012 Model S, beat GM
to market with their own skateboard EVs.
Borroni-Bird said he was not surprised
when Tesla showed the Model S concept in
2009 with the skateboard chassis.
" I knew that the economics of the [electric]
powertrain were such that if you could
up production, the best solution at scale
was the skateboard. Once the battery costs
came down - and obviously Tesla was first
to do that - then other automakers jumped
on board. "
NEWFOUND FREEDOM
The skateboard chassis has given
designers unprecedented freedom to focus
on getting the proportions of a car just
right and to increase interior room.
" The architecture doesn't interfere
with the top hat of the vehicle, " said Mike
Simcoe, global vice-president of design at
GM. " Structurally, the skateboard effectively
stops at the floorpan. And so everything
above that is free. In a traditional build,
things like the cowl and dash panel and the
front hinge pillars are controlled by things
The Opel Filo concept, shown in 2001
in Geneva, featured drive-by-wire
technology and a flat floor. FILE PHOTO
Cadillac Celestiq: Generous interior
space, thanks to the skateboard.
FILE PHOTO
coming out of the chassis, such as engines,
fuel tanks, etc. But in a skateboard, it's all
down low, and you've got more freedom.
" You ... express it by proportion. You
can do a long dash-to-axle, you can do a tall
vehicle. It's all governed by the H-point, "
he said, referring to the theoretical pivoting
point of a passenger's hip, which influences
everything from roof height to interior
space to ease of entry and exit.
Some of the latest EVs, such as the
Lucid Air, the Rivian R1T pickup and the
upcoming Cadillac Celestiq, demonstrate
the advantage of the skateboard chassis.
These vehicles have generous interior
space relative to their body sizes, and in
the case of the R1T, ample storage areas
not available in body-on-frame pickups.
Because electric motors are smaller
than gasoline engines and require fewer
umbilicals, such as cooling and exhaust
hookups, engineers can put drive motors
in the front axle, in the rear axle, or
both in the case of all-wheel-drive vehicles.
If the Lordstown Endurance pickup
launches, it will be the first modern regular-production
vehicle to have the motors
in the wheel hubs. The Endurance has its
battery pack mounted between the frame
rails, though it still uses a fairly traditional
rugged steel truck frame.
Roush's Fraker believes one of the
skateboard's limitations is that it isn't
suited to replace the frames used on
hardworking vehicles, such as heavy-duty
trucks that haul huge loads.
" I think it will be quite a few years
before we see significant trucks that handle
large loads go to the skateboard, " he
said. " Those frame rails give us excellent
strength, and I think they will persevere in
the commercial market. But everything in
the lighter classes, you will see more integration
of the battery and the vehicle. "
- ANC
Automotive News Canada - September 2022

Table of Contents for the Digital Edition of Automotive News Canada - September 2022
