Like this site? Help us to make it better.


British carbon specialist Filament launches new Super Duty frame

New UK-made carbon frame maximises stiffness with octagonal profile tubes

Filament Bikes (formally Craddock Cycles) is a British carbon fibre frame specialist that has for the last few years been building some stunning bikes, and it has just launched a new model called the Super Duty.

The Super Duty gets a completely new carbon fibre tubeset with a focus on increasing the overall frame stiffness, aimed at appealing to more powerful cyclists.

filament super duty6.jpeg

Craddock has developed a  larger octagonal profile and it's used in the top tube and down tube. There are also brand new rear stays. The top tube is noticeably more flared where it meets the head tube than regular Filament models, and the down tube looks positively massive.

Filament provides a fully bespoke service. You can customise the geometry if you have a particular preference, choose disc or rim brakes, choose from three bottom brackets and a cable routing option to match your groupset, mechanical, wired or wireless. There are also seven stock sizes if you don’t want or need a custom setup.

filament super duty1.jpeg

Once you’ve chosen your frame details, all that remains is to choose the paint colour and design. Personally, I’m all over the orange with black splatter finish.

Frames will be supplied with colour matched Enve forks and Chris King headsets. Current delivery time is eight weeks and the frameset costs £3,600.

The majority of carbon fibre frames are made in the Far East. Huge manufacturing investment has gradually brought down the price of a carbon fibre bicycle frame, and they’re now more affordable than they ever used to be.

filament super duty3.jpeg

Craddock set out with the bold ambition to build its own carbon frames here in the UK. Founder Richard Craddock has built his very own composite production facility in Worcestershire and produces in the region of 50 frames a year. This isn’t a production line approach to frame building, it’s a fully bespoke service with hours poured into producing each frame.

Craddock constructs each frame with precisely mitred roll wrapped carbon tubes before wrapping the joints with pre-impregnated carbon fibre, and then curing the frame under pressure in an oven, much the same process as many top-end carbon frames. The process allows for custom geometry, as well as being able to optimise the frame for its intended use and rider weight through tube choice. You can learn more about his construction technique here.

More details at

David worked on the tech team from 2012-2020. Previously he was editor of and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes

Latest Comments