Support us! BikeRumor may earn a small commission from affiliate links in this article. Learn more.
Tom Sturdy has long been making use of additive manufacturing to build some of the most stunning titanium road, gravel and hardtail mountain bikes on the market. Sturdy Cycles comprise a unique combination of drawn tubing welded to 3D printed junctions of Tom’s own design, fitted out with custom 3D-printed titanium parts including fork, stem, crankset and seat-post. Until now, you could only get your hands on any of these parts if you were purchasing a custom frameset, such as the Sturdy Cycles Fiadh Road Bike that will leave you at least £8,000 out of pocket.
Now, Tom is making his custom 3D-printed titanium crankset available to everyone as a standalone part, with crank length customizable well beyond the range of what is typically commercially available without compromising on the performance of the crank.
All photos by Adam Gasson
Sturdy Cycles 3D-Printed Titanium Cranksets for Road and MTB
The shortest arms Tom Sturdy has made to date have been 125mm, and cranks in the 150mm range are fairly common too.
The arms are manufactured additively from “6/4” titanium and, as with all the parts Tom designs for additive manufacturing, they make use of sophisticated continuously variable hollow geometry in order to use material as effectively as possible. “They look quite different to other ‘printed’ cranks (and other parts) that often use ‘generative’ design to determine the form of a part. I actually draw quite heavily on generative design in the early stages of development and find it to be a really useful tool combined with physical testing to help determine how the material should be distributed” – Tom Sturdy.
“In line with my broader design philosophy, absolute minimum weight was not the headline but instead what I consider to be a well balanced set of mechanical characteristics (initially to complement the mechanical performance of my frames) whilst remaining competitive in the weight department. The printed alloy achieves very high strength compared to other materials used in crank manufacture which makes them very robust”.
Tom is able to make custom road and mountain bike cranksets. These differ in their geometries in order to cater for the different clearance requirements at the stays. Tom tells us they are both built around the same load cases but with extra material added to the MTB version to account for the less ‘predictable’ usage.
The road crankset with 170mm arms weighs a claimed 445g, without a chainring. The MTB Crankset with the same length arms weighs a claimed 485g.
The axles are also 6/4 titanium. These are machined to suit a 30mm bearing and is a separate part which interfaces with each arm via a tapered lobed interface, secured by a central retaining bolt. All of the hardware is also titanium (either machined or printed). By default, Tom leaves the crank arms in their ‘raw’ state but can also achieve a range of striking finishes with anodizing and, on occasion, admits to being foolish enough to agree to mirror polishing.
To go with your titanium crank arms, Tom can make you a titanium chainring too. He’s only ready to move on 1x options at the minute but is working on a 2x setup as we speak. “These were really conceived to complement the cranks and ultimately my frames. The pattern of the webbing in the crank is an example of a nod to a design ‘feature’ that is repeated in multiple applications throughout the bikes, although most of them are hidden away from view. They also offer superior longevity to aluminum rings which tend to wear quite fast with 1x setups”.
“Ever since rolling these parts out onto my bikes I received requests for them as a standalone item. It has taken me a really long time to get to a position where I am happy to offer that as they are a particularly complex part to manufacture and I wanted each stage to be well proved out” – Tom Sturdy.
Tom is also working on a version of these bar stems that has a wider range of compatibility with other headset/steerer arrangements
Pricing & Availability
A 3D-Printed Titanium Crankset from Sturdy Cycles will set you back £1200 without the chainring, which retails at an extra £250. No word on pricing for the coming 2X cranksets just yet – Tom is still working on refinement of production to figure out long term costs.
Jessie-May Morgan is the UK & Ireland Tech Editor of Bikerumor. She has been writing about Mountain Bike Riding and Racing, and all its weird and wonderful technology for 4 years. Prior to that, she was an Intern at the Mountain Bike Center of Scotland, and a Mountain Bike Coach and Leader in the Tweed Valley.
Based in Innerleithen, Scotland, Jessie-May can often be seen riding the Glentress Trail Center, and its neighboring Enduro and Downhill Tracks. She regularly competes in Enduro at a national level, and has recently competed on the World Stage at a handful of Enduro World Series events.
For Bikerumor, Jessie-May is testing the latest mountain bikes, equipment and kit, letting readers know what’s hot and what’s not.
For context, she weighs 60kg and stands at 5ft 4″ tall (163cm).