(L-R) Engineers Ben Schultz, James Woolcock, and Dean McGeary started Bastion Cycles with the help of their redundancy payouts from Toyota. [Image: Luis Enrique Ascui]
The company sells self-assembled frame sets starting at less than $10,000, but for a full build bicycle, which includes a customer fitting, 3D printed titanium lugs (socket sleeves), and hand assembly, the price can range between $13,000 and $25,000.
We often see 3D printing put to use making accessories, components, and parts for bicycles.
Another bespoke bicycle company in Australia using 3D printing is Prova Cycles, which shares a workshop with Bastion and recently won big at Bespoked, the UK Handmade Bicycle Show.
Mark Hester, the owner of Prova, builds and welds each custom frame by hand, so that the fit, geometry, and tube selection are a perfect fit to the rider. After he attended a Bespoke show some years ago, Hester fell in love with bicycle building, and after some time at The Bicycle Academy, built his first hardtail bike in 2015; now, it’s his full-time job.
Hester recently made the trek from Melbourne with three exhibition bikes to the 8th Bespoked show, including a hardtail model called the Ripido, which features a steel, 2.1 kg frame with a couple of 3D printed components.
The Ripido mountain bike, painted pink with gold flecks with an RRP of $3,500 AUD, features TIG-welded Reynolds 853 steel tubing, a 66° head angle and 74.8°C seat angle, and 29″ wheels, with clearance for 2.6″ wide tires.
Two sections of the frame – the driveside chainstay yoke and the non-driveside dropout – were 3D printed using stainless steel, which Wil Barrett says in a Singletrack post is “something we’ve not seen on a mountain bike frame before.”
Hester has a background in automotive and mechanical engineering, so he knew what he was doing when he went with stainless steel instead of titanium for the 3D printed components. Each part is hollow, with thin walls and interior lattice structures – these features make it incredibly lightweight, yet also incredibly strong.
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- 3D printed non-drive dropout
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- 3D printed dropped chainstay yoke
Barrett wrote, “These have then been TIG-welded to the chainstays and seatstays with such incredibly fluid lines that I challenge you to spot where the intersections are.”
A company in New Zealand used SLM technology to 3D print the lugs for the Ripido out of 15-5 PH stainless steel.
“It is a very strong material with great elongation at break, so it’s very tough,” Hester explained. “It is readily weldable to materials like 853 and 4130 with the correct filler rods.”
Hester, whose favorite features of the Ripido are its paint scheme and brake side dropout implantation, said that one of the advantages of using 3D printed sections to make the bike frame was “basically infinite flexibility,” as he was able to customize the initial design in ways that would not have been possible through casting or CNC machining.
“Dropping the chainstay for tyre and chainring clearance means the cross section of the RH chain stay doesn’t need to reduce drastically right at the point where so many bikes fail,” Hester said.
However, there were some challenges to surmount before the 3D printed sections were completed.
“Compared to purchasing dropouts and building yokes from steel plate, there is a huge amount of CAD design and simulation involved with developing the 3D printed components,” Hester said. “Being a different process it has also required lots of testing to ensure the bike is fit for purpose.”
But Hester’s level of attention to detail and design aesthetic paid off, and the Prova Cycles Ripido, with its 3D printed frame components, won the Singletrack Choice Award at Bespoked 2018.
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[Images: Singletrack]
