Currently reading: Ariel developing titanium chassis
Lightweight chassis will reduce Atom's overall weight by almost 8 per cent

Ariel is developing a titanium chassis for its Ariel Atom sports car that weighs 40 per cent less than the Atom's tubular steel frame, and is capable of reducing the car's overall weight by almost eight per cent.

Titanium is incredibly strong – it has the highest strength-to-weight ratio of any metal – but it's also extremely difficult to fabricate. If exposed to oxygen during welding, titanium combusts before it melts, hence the necessity for a complicated, argon-filled welding chamber. 

The frame and the welding process have been developed alongside Frome-based Caged Laser Engineering, and part-funded for by the Technology Strategy Board’s Niche Vehicle Programme fund.

Ariel's Simon Saunders told Autocar that, when development is complete, "We'd like to do a limited edition. It would be a brilliant track car. The alternative would be to offer it as an option on the range."

With a naturally aspirated Honda engine and some other selected light components, the frame could help push a limited-edition Ariel Atom's weight below 500kg. "Our magic figure would start with a four," said Saunders, though he concedes that it would be difficult, and that 500kg on the nose would be a more likely target. 

When it was launched, the Atom had a very lightweight Rover K-Series engine. However, the current range of Honda engines are heavier, albeit far more reliable.

As well as proving useful on the Ariel Atom, however, Ariel thinks the experience it gains in working with titanium will also be useful on its future products, possibly including its forthcoming motorcycle.

Matt Prior

Matt Prior
Title: Editor-at-large

Matt is Autocar’s lead features writer and presenter, is the main face of Autocar’s YouTube channel, presents the My Week In Cars podcast and has written his weekly column, Tester’s Notes, since 2013.

Matt is an automotive engineer who has been writing and talking about cars since 1997. He joined Autocar in 2005 as deputy road test editor, prior to which he was road test editor and world rally editor for Channel 4’s automotive website, 4Car. 

Into all things engineering and automotive from any era, Matt is as comfortable regularly contributing to sibling titles Move Electric and Classic & Sports Car as he is writing for Autocar. He has a racing licence, and some malfunctioning classic cars and motorbikes. 

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jer 25 March 2013

light engies

K series always used as a reference to light 4cyl engines but I wonder who currently makes the lightest engines with ancilliaries. Fords A4 1.0? I Suppose the motorcycle world is the benchmark where complete 1litre bikes weight <200kg.

stavers 25 March 2013

jer wrote: who

jer wrote:

who currently makes the lightest engines with ancilliaries. Fords A4 1.0?.

Definitely not.  The block is cast iron and it doesn't weight much less (only a few 10s of kilos) than the bigger 1.6L 4 cylinder.

simonali 24 March 2013

The modern titanium alloys

The modern titanium alloys mentioned by Old Toad are quite easily welded without an argon chamber, just as long as the metal is clean and there is a good gas shield around the weld.

Cyborg 24 March 2013


Ariel are developing a motorcycle! This is the first time I've heard that. Looking forward to see the result.