Reportage

Prova Cycles: Lean Manufacturing

John and Cari were in Melbourne for a few days following the 2024 MADE Australia showcase, which gave them some free time to visit a couple of shops, one of which was Prova Cycles.

Nestled inside this compact factory, siblings Mark and Kelly Hester build some of the most advanced bikes in the world. This two-person team has optimized production over the past four years, and it’s something to behold…

Prova Genesis

Mark Hester began his engineering background by designing and racing automobiles. Having grown up building one-off race cars with his father, his technical schooling was a continuation of this hobby. His lifelong passion crescendoed during his final thesis project, where he designed and manufactured a carbon fiber formula race car chassis using monocoque construction. It was the first autoclave-cured tub made in Australia!

To test this remarkable product, Mark entered it in the FSAE-A competition in 2004 and placed 2nd overall. He then traveled to the USA in 2005 for the largest completion of its size in the world, set the fastest lap times in the enduro, and placed 4th of 140+ teams in the design competition.

All this to say, Mark fast-tracked his career in the world of automotive design, working for Prodrive, Bosch, and Jaguar Land Rover, where he helped design and test prototypes around the globe. Yet bicycles were a lifelong passion of Mark’s, and eventually, he left the automotive world to open Prova Cycles in 2015.

In 2020, his sister Kelly joined the team from a career of being a baker to make Prova’s carbon fiber seat tubes. Kelly’s organizational skills from running bakeries have propelled Prova onto a higher level of production. Thanks to Prova’s adoption of the Japanese methodology for organizing stages of tasks onto boards called Kanban, the two have optimized production in this relatively small factory.

Lean Manufacturing

“I began listening to Lichen and Austere’s podcast, Incremental: The Continuous Improvement, and a lot of what they talk about is lean manufacturing… They do a great job of translating the principles designed for much bigger companies with useful examples for small shops.”

Mark said to me, jumping right into Prova’s modus operandi during my shop visit.

“I came across their podcast a few years after we started the lean manufacturing journey. Originally, my thoughts were that doing small batches was going to be the way, and even I recall listening to Rob English talking about lean on the Cobra podcast and not being able to understand why you wouldn’t batch. We now only try to do one of each process needed to make one frame and there was a lot of pain trying to make that work.”

Prova’s goal is to have one bike leave from its shop a week. In this system, manufacturers produce the parts needed to create the whole in advance, keeping the inventory lean and then moving each part through the various stages of production.

Mark’s engineering background enabled him to utilize tools like Fusion 360, a 3D modeling program, and FEA, or finite element analysis, to assist in his structural design for additive manufacturing and prototyping. These skills have informed Prova’s manufacturing intent.

Step By Step

As mentioned, Kelly and Mark use a Japanese system called Kanban, which translates to “signboard.” Kanban organization relies on every stage in the project’s process and is represented as a separate card on the display board. The main purpose of representing work as a card on the Kanban board is to allow team members to track progress through its workflow in a highly visual manner. Every morning, Kelly and Mark discuss the progress, and the Kanban system is updated, assigning each of their duties for the day.

Similar to Darren Baum’s technique of order queue organization – check out our Shop Visit from 2014 here – Kelly and Mark have bins with customer’s components in the office upstairs and below in the factory, each customer has a kit of parts on the production floor. Their future bike’s tubesets, along with 3D printed parts (more on that below) are in a drawer with a label. Each bike has its own clipboard displaying its checklist of to-do items.

Capture from Fusion 360 CAD showing Prova’s road sliding dropout model Prova hs used on a few single-speed disc Integrale frames and the 3D printed sample.

Parts of the Whole

During my architecture education and throughout my career, we utilized parametric design to inform construction. Parametric design creates a 3D model based on a series of integers. In a building, these 3D models begin as complex forms, and each curve along that form is used to design the structure and various systems that support it.

Parameter input to CAD with the Mostro Integrale model

What this means is as the form of the building changes, the multi-dimensional materials change with it. If you alter a single line, the ripple effect across beams, hardware, glass, or cladding is automated, saving hundreds, if not thousands of hours. Architects like Frank Gehry, Zaha Hadid, and others uses these systems to create complex forms and façades in their award-winning buildings.

Bicycles are inherently less complex than buildings, but Mark works with parametric design on each and every Prova. Similar to the discussion that unfolded in the Eisentraut piece I posted last week, bicycles are made from angles, and how those various angles attach has evolved over the history of bicycle fabrication.

In the early days, builders would fillet braze tube-to-tube construction on a flat alignment table. Then came hand-carved lugs. The next step was investment casting, where a manufacturer like Beretta could cast thousands of lugs at different tubing angles to fast-track production. With this kit of parts on hand, production increased exponentially as countless hours were saved by brazing tubes into investment-cast lugs.

We’ve looked at other brands like Neuhaus Metalworks and its system of producing 3D sintered, aka printed, components in Shanghai, China, en masse and then welding frames together in the US. In many ways, 3D-printed frame components are enabling builders to speed up their building process, just as investment casting did in the late 1980s for Italian framebuilders like Cinelli, Masi, and others.

Mark’s process at Prova is slightly different for a few reasons. Rather than offer stock sizing, Prova offers completely custom fabrication. Each of Prova’s bike models has a parametric 3D model. This allows Mark to change intergers like the angles, bottom bracket drop, and chainstay length. As he alters these parameters, the parametric model updates, creating a unique 3D-modeled part. FEA is applied to ensure the parts pass the testing, and from there, he sends the customer’s frame parts out to a New Zealand-based 3D printer that can manufacture parts in a short turnaround.

Once the parts are received in Melbourne at Prova’s factory, they go into a rock tumbler before Kelly hand-finishes them all with a combination of various air tools. Mark then cuts the US-made and -sourced titanium tubesets as per the computer-generated 3D model and begins to weld the frames.

Meanwhile, for the models that require a carbon seat tube, like the Integrale, Kelly makes each one by hand in-house. She and I had a conversation about transitioning from making pastries to making carbon fiber bicycle tubes, and her comment resonated with me:

“It’s just like following a recipe. You have a list of ingredients and a procedure you follow. In doing so, it keeps the quality of the product consistent.”

Kelly spent over a decade working in breakfast bakeries and began helping Mark in 2020 during Victoria’s strict pandemic lockdown. Since bicycles and manufacturing were deemed essential, Kelly found a new career path and now gets to work alongside her brother each day in this small yet efficient factory. This efficiency took a concerted effort between her and Mark, who wanted to keep their order queue for around twelve months.

And it’s all thanks to lean manufacturing and some unique fabrication techniques…

Titanium Processes

Titanium framebuilding requires a two-pass weld for each mitered tube junction. This is just one reason why titanium frames are so expensive to produce. That means, essentially, two steel frames could be welded in the time it takes a single titanium frame to be completed. Adding to the complexity is a lengthy purging setup.

Titanium purging uses an inert gas such as Argon to protect the underside of the weld from oxygen, hydrogen, and nitrogen contamination. It can take up to two minutes for the system to hit optimized levels of around 50 PPM before welding in that area can continue.

Adding to the purging process is the painstaking monitoring of the heat applied to each tube as each welding pass goes down. Builders will move around the frame to minimize the tacked tubes from heating and deforming out of square. Because mitered tubes require two welding passes, the time required adds up, especially around tough-to-reach areas like seatstays and bottom brackets. All this to say that welding titanium is very labor-intensive.

A titanium fabricator is always looking for ways to shorten this lengthy process, not only to save time and money but also to protect their bodies, as hunching over a welding station locked into extreme focus causes sore muscles and tension.

One unique way Prova optimizes frame production is by using a lip around each of its 3D-printed components. This lip gets melted down into the weld bead. So, for each connection like this, Mark doesn’t use a weld rod; he uses the actual 3D-printed component to join the tubes. This enables optimal penetration, eliminating the need for a second pass versus two passes of the traditionally welded mitered connections.

Another assemblage method Prova deploys on its frames is a 45º beveled sleeved connection, shown above in Prova’s prototype titanium fork. In this instance, the pieces are slid into position, and a filler rod is used to weld them together, creating a flush surface between the two pieces. These connections save both time and money and for a small shop like Prova, it all adds up.

Prova collaborated with Sturdy Frames on these fork uppers.

In the world of titanium framebuilding, it is very common for builders like Baum Cycles, Sturdy Frames, and Prova Cycles to share techniques and technologies. As the old saying goes, the cream rises to the top!

Finishing and Ten Thousand Touches

Cari and I often say that creative endeavors require ten thousand touches, and the same can be said for each and every Prova frame. Between the ordering and organization of frame components, tubing selection, 3D-printed parts prep work, welding, and finishing, Mark and Kelly touch each part of this process, all adding up to a pristine presentation.

Once Mark has finished welding the frames, Kelly takes them back to her station to polish the exposed titanium and prep the frame for paint. Prova uses Velocraft for paint and the Victoria-based paint shop’s reputation shines with each bike that rolls out from this factory. But first, the frame must get built before it can roll on its own two wheels.

Dan from Superbe Velo Service comes into the Prova factory when his services are required and assembles each complete bike. On a personal note, my early rides into the Aussie bush with Dan inspired this website; his fine work can be found all throughout our archives.

Prova leans on its talented network of craftspeople to finely tailor each bike to its customers, and the final product is nothing short of perfection. Let’s take a look at a freshly-completed bike that rolled out of the shop while I was visiting. Dan and I discussed integrated gravel and road bikes while he was building this Prova Integrale. He mentioned how easy Provas build up with integrated housing and cables.

Dan’s work can be seen below across three stunning builds.

Prova Speciale Integrale Disc Road

While visiting the Prova factory, I was able to document this exquisite Prova Speciale, their titanium disc or rim brake road bike with a carbon seat mast. This one features a Velocraft paint job with stunning masking that transitions from polished titanium to paint. The custom-formed oval chainstays and signature 3D-printed dropouts are left matte/raw for easy cleaning. As a fully integrated model, the Integrale utilizes the ENVE INTG disc fork with a custom 3D-printed Prova headtube.

Speciale Integrale Specs:

  • In-house butted 3/2.5 seamless tubing
  • In-house designed and manufactured internally butted carbon ISP
  • Custom-formed oval chain stays
  • 34 mm tire clearance
  • In-house designed and 3D printed titanium dropouts and lugs
  • Full custom sizing and geo
  • Enve INTG Disc fork
  • Fully internal routing
  • Typical frame weight 1320-1380g inc seat mast

Prova Cycles Mostro Drop Bar MTB

While in Melbourne, I also documented this Mostro drop-bar 29er MTB with a Pinion Smart.Shift gearbox at the 2024 MADE bike showcase.

It utilizes TRP’s all-new drop bar Hywire shifters and a Gates belt drive. The beautifully designed sliding dropouts allow for 25 mm of adjustment for dialing in the perfect belt tension. These dropouts, along with the Pinion cradle/yoke, are 3D-printed in New Zealand and are industrial design projects on their own.

What is perhaps most striking about the bike is the raw finishing, atypical for Prova, who is known for its meticulous and perfect paint jobs.

Mostro MTB Specs:

  • In-house butted 3/2.5 seamless tubing
  • Custom-formed tubing for seat tube and stays
  • In-house designed and 3D printed Titanium dropouts and dropped chain stay yoke
  • Full custom sizing and geo
  • Enve Gravel or Enve Adventure fork with light, rack, and fender mounts
  • Typical frame weight 1500-1600g

Prova Integrale LW Speciale Disc

Speaking of flashy paint! This stunning red Prova Speciale Disc was on display before being handed off to the customer. It features wet 2pac paint by Velocraft, which is also based in Melbourne. The high-polished titanium is completed in-house.

Shooting bikes like this is equal parts adoration and anxiety! They don’t want to sit still while photographing, and rightfully so. The aim for the Speciale was to create one of the lightest metal road frames. The Integrale is Prova’s take on the clean aesthetic of the hidden cable or integrated bike. It takes the Speciale platform and adds a unique headtube design using a CNC-machined lower section with a Prova-designed 3D printed upper. The bearings are Ceramic Speed solid lube bearings, and the aero cover and lock ring are Prova-designed and made of titanium. The perfect balance between road and “all-road” is measured by the Integrale LW, which has a maximum tire size of 34 mm.

Spy shots of the new Prova Mostro Integrale

What’s Next?

Prova will unveil two new models at MADE this year and while I’m saving one for a surprise, I got an intimate look at its new gravel model, dubbed the Mostro Integrale, which utilizes a titanium fork, a hidden seatpost wedge, custom Chris King integrated cockpit, a dropped chainstay, and clearance for a 50 mm tire.

The other bike… well, we’ll just say it’s got a lot of bounce per ounce! Stay tuned…

I’d like to thank Kelly and Mark from Prova Cycles and Dan from Superbe Velo Service for letting me poke around the factory for a sunny winter morning in July. As a lifelong lover of framebuilders, these “behind the curtain” stories are my favorite form of content we produce here at The Radavist, especially when it comes to seeing the process behind what I truly believe are some of the best bikes in the world.

See ya at MADE!

Check out more at Prova Cycles.