Behind the Curtain: Mosaic Cycles factory tour

The bikes are impressive, but it’s the systems and processes that make it a viable business.

James Huang
by James Huang 12.12.2023 Photography by
James Huang
More from James +

Aaron Barcheck founded Mosaic Cycles in 2009 in Boulder, Colorado, with the goal of becoming a premium builder of custom titanium and steel bicycle frames. Almost fifteen years later, Mosaic essentially now builds on only in titanium – steel will only be featured in “limited editions” moving forward – and Barcheck has earned a reputation of one of the premier builders in the category. 

You want that coveted stack of dimes? He’s got you.

“When I founded Mosaic in 2009 I had two main goals. First was to create an environment where this type of work can be done professionally,” Barcheck said. “I wanted to have a career in manufacturing frames and wanted space for this work to continue into the future for myself and others. And second I wanted handmade bicycles to have a larger presence in the bicycle world. I felt, and still do, the approach we take to making metal bikes has so much to offer and wanted to be a part of bringing this to a larger audience.”

Some titanium-focused brands seem compelled to push the technology envelope with things like more radical tube shaping and advanced manufacturing processes like 3D printing. However, Mosaic has so far been content to stick with the tried and true. The tubing is mostly round with more traditional-looking bends, and parts are still CNC machined, with material cut away from a bigger hunk of metal instead of iteratively built grain-by-grain with a laser. And not only are anodized finishes still not on the Mosaic menu of options, the company doubled down on paint after purchasing Spectrum Powder Works (now Spectrum Paint and Powderworks) in 2016. 

Call Barcheck stubborn if you’d like, but the formula is working. 

The company is on track to build around 350 frames in 2023, and while some high-end brands are seeing painfully dramatic reversals of fortune from pre-COVID times, Mosaic is supposedly still growing. In fact, Barcheck is currently looking to add a customer service person and another painter to their small-and-efficient team of six. 

What’s the secret? While the bikes are widely viewed as truly premium, the fact of the matter is there isn’t a ton physically that elevates a Mosaic above its competition. Instead, Barcheck would argue it’s the business systems and production processes he put in place years ago. 

Most Mosaic frames aren’t manufactured entirely from raw tubing when an order is placed. Instead, the majority of the sub-assemblies that go into a frame are actually already built in batches well in advance. Dropouts are already welded to pre-bent chainstays, main tubes are already cut to approximate lengths, and so on. In many cases, it’s just a matter of finalizing the tubing lengths and miters, and assembling the assortment of small bits a customer requests. Want a stock geometry? There’s a good chance the one you want is mostly done, already welded up and hanging on a rack, and waiting for final touches like chainstay and seatstay bridges, bottle and accessory mounts, and finish. 

All of this planning allows Mosaic to put a custom frame in a dealer’s hands supposedly just six weeks from the time a customer places an order, including paint – a fraction of the time quoted by most other brands. Litespeed’s currently quoting 12-15 weeks. Seven Cycles is better at nine. Sage? 10-12 weeks. No. 22? 25. For some particularly boutiquey brands, the wait can be far longer.

You get the point.

Six weeks still isn’t quite the instant gratification you can get from buying a bike straight off the showroom floor, but in this world, that’s awfully close.

Next up in our Behind the Curtain series of factory tours: Bridge Bike Works and Framework Bicycles. And got any suggestions for other factories we should visit? Let us know in the comment section.

Mosaic employee Ross Leopold operates a large tubing cutter, which looks a bit like a table saw.
Almost universally, the very first step in making a titanium frame is cutting raw tubing to length. Pictured here is lead framebuilder Jamie Appleton.
A very clean, orderly work station in Mosaic's factory where builds are started.
You might say this is the heart of Mosaic’s production process. Here, materials are gathered based on order sheets that are filed at left.
Piles of frame sub-assemblies sit in neat, stacked rows in a case.
Mosaic doesn’t build each frame completely from scratch. Instead, the company pre-builds most of the subassemblies each frame will need. It doesn’t cut a huge amount of time on a single frame, but compounded, it makes for major gains in efficiency.
A closeup of chainstay sub-assemblies for various models.
Chainstays for various models are shown here. Since chainstay lengths don’t vary too much by model, each pair only needs to be mitered before it’s basically ready to weld. Obviously, there’s an art and science to forecasting what will be needed months ahead of time.
Neat stacks of seatstays, pre-cut and bent.
Seatstays are another thing that can be bent and prepped ahead of time.
A batch of chainstays sits on a work bench for prep.
A batch of ten chainstay pairs getting prepped to have dropouts welded.
Rows of stem parts are lined up in a drawer of a tool chest.
Small parts are stored in a battery of drawers. Need a custom titanium stem? Mosaic has got you.
A stack of main tubes sits divided by cardboard spacers.
Main tubes for stock geometries are also pre-cut to length. But do you see how the ends are all lined up with the edge of the box? That’s because the bottom is backed with an angled board so shorter tubes aren’t lost in a black hole.
Plastic bins hold dropouts and brake mounts, already prepped for welding.
Dropouts and brake mounts lined up and ready to go.
Another drawer in a tool chest holds an array of titanium bits for cable routing, axle nuts, and other uses.
A smorgasbord of machined titanium bits …
A closeup of external housing stops in the drawer of small parts.
… and a lifetime’s supply of external housing stops.
Small parts sit in zippered plastic baggies with a number corresponding to the frame order.
Small bits are gathered per frame, and labeled by order number.
A manual tube bender is shown, with a large lever arm for manipulating tube shape extending from one side.
Tube bending is done in-house – and manually.
A row of electric machine tools in Mosaic's factory: vertical drilling presses and mills, all set up for one specific part of the process.
Mosaic has an impressive assortment of machining tools inside its workshop in Boulder, Colorado. Each machine is set up to basically do a single job so there isn’t time wasted changing configurations.
A large electric machine tool sits idle on the floor of the Mosaic workshop.
It was quiet the first day I stopped by the shop, but anything but the second day. These machines are loud.
An industrial-size ultrasonic cleanser, several feet wide, sits on a workbench.
This ultrasonic cleaner is big enough to fit an entire frame’s worth of tubing and parts.
A weathered bench vise has its clamps covered in copper jaws.
Copper vise jaw caps prevent damage to titanium parts.
An electric machine tool cuts a precise miter into a titanium frame.
You can’t get a good welded titanium frame without an accurate miter.
Frame schematics are shown on four sheets: they cover the dimensions, tubing, color, and other details for every order.
Everything the builder needs to know is on these four pieces of paper.
Another neat workbench in the Mosaic factory, with a cubby underneath divided into storage for various builds - each cubby contains an order.
Each one of these cubbies contains one frame’s worth of components.
A closeup of the cubbies, showing a pile of tubes in each, with the model name and size.
So close, yet still so far away.
One of the order sheets in closeup, showing extensively detailed information on the customer's geometry and other specs like cable routing and rack mounts.
The devil is in the details, no? Every mount is carefully noted on the weld checklist.
Two frame welding jigs sit on the floor; they're on rolling casters.
Frame jigs are mounted on rolling frames so they can be easily moved around the shop.
One of the TIG welding stations; it's a small affair with a frame jig on a small table and a standard office chair, accompanied by a tool case and welding equipment.
Mosaic Cycles has two dedicated TIG welding stations. I was surprised at the relative lack of lighting, until Mosaic Cycles founder and welder Aaron Barcheck reminded me that if anything, the TIG welding process itself produces too much light, hence the welding masks to protect against burned retinas.
A closeup of a frame in a welding jig, showing the first run of "fusion welds" to essentially tack the tubes together. Shown is the seat cluster.
Frame tubes are set up in the jig and then initially joined with fusion welds. The gaps shown here are areas that are hard to reach in the frame jig, so those are finished up just before finish welding.
Ross Leopold holds a set of calipers up to a seatstay to measure the width of a bridge.
Mosaic employee Ross Leopold carefully measures the chainstay and seatstay bridges by hand.
A set of calipers and other tools sits on a bench alongside a customer order sheet.
More checklists.
A frame readied for welding has the holes for bottle mounts and cable routing sealed to keep the argon gas inside the tubes.
Titanium can react with atmospheric oxygen during welding, creating a weak area prone to cracking. To prevent this, frames are backpurged with argon – an inert gas. Holes are sealed with either masking tape or aluminum foil to keep the gas from leaking out.
A closeup of the bottom bracket section on a frame, showing a first pass of fusion welds and close miter tolerances on the unwelded portions.
Remember what I said about miters? This is about as tight as it gets.
A frame in welding has the order number and instructions penned in Sharpie on the top tube.
Frames will eventually be media blasted, anyway, so there’s no harm in writing order details in Sharpie right on the top tube.
A closeup of a fusion-welded BB shell from behind, showing the perfect symmetry of the chainstays and BB shell.
There’s beauty in symmetry.
A welder fixes a titanium internal cable-guide tube inside a frame.
On frames with partially internal routing, the brake hoses are fully guided using a titanium tube that needs to be welded in place.
The internal guide is welded to the tube and sticks out slightly like a branch broken off.
A short stub remains immediately after welding …
After finishing, the protruding guide tube is gone, showing only a flush internal fitting.
… but it’s then ground down to leave a flush fitting.
A frame is tacked up and ready for final welding in a stand.
All tacked up, sealed up, and ready for final welding.
A neat and orderly welding station with a welding control module, mask, tungsten rod and small parts along with the order sheet.
A place for everything, and everything in its place.
Aaron Barcheck holds his hands out to show weathered gloves with holes in several fingers.
Aaron Barcheck needs some new gloves.
A grimacing Barcheck with slightly less-beat-to-hell gloves.
A row of frame fittings sits on a rag with tape for a frame order.
Bridges and fittings neatly gathered up.
Two piles of tungsten electrode rods sit on a rag on a bench.
The tungsten electrodes are consumables, so it’s important to have enough on hand.
A welder in weathered Keen boots operates a welding foot pedal to control amperage. The boots are stained and dappled with paint and other substances.
The foot pedal controls the amperage during welding. These boots have seen some things.
A welding control panel showing settings for key controls like peak amperage, pulses per second and background amperage.
Barcheck carefully guarded the settings on his TIG welder when I first visited him almost 10 years ago, but these days, he’s not so worried. According to him, anyone is free to recreate these “adult mode” settings exactly, but unless they have the skill and experience to go with it, it won’t do them much good.
A small neat stack of titanium welding rods in a workstation.
Lots of titanium welding rods at the ready.
A welder in an American-flag stylized mask leans in to weld a bottom bracket juncture. His hands are brightly lit by the welding arc.
And here we go.
Another view of welding the bottom bracket, showing the welder with a torch in one hand, welding rod in another.
Steady as she goes.
A closeup of a head tube weld, with the welding arc obscured by a tube, light from behind.
Barcheck says he most definitely gets into a zone when he’s welding. In fact, sometimes he doesn’t even bother to turn the lights on in the workshop if he’s working by himself, since all he needs to see is the little rectangle outlined by his welding mask and lit up with his welding torch.
Another closeup of welding, showing the argon gas tool purging the outside of the weld area.
More argon gas is piped through the welding gun to keep the entire area flooded in inert gas.
A fusion weld on a bottom bracket. The welds are puddled but raw, and the frame glows red where the chainstay meets the bottom bracket shell as the welder passes.
Fusion welds melt the adjoining tubes together, while the second weld builds up the area for added strength. “A few really acute angles get extra filler,” Barcheck explained, “but a finish pass mostly consists of one final pass to get the dimes stacked correctly.”
A closeup of a finished weld, showing close, perfectly spaced weld fillets or puddles.
Dimes, freshly stacked.
Another station in the Mosaic factory showing an alignment jig for facing and finish prep.
Freshly welded frames still need some finish work before they’re ready for finishing: alignment as needed, reaming, facing, chasing.
Rows of welded frames sit on a wall. There are roughly 50 in view, all still raw with no finish.
Scores of frames in various states of production hang throughout the Mosaic workshop. Barcheck says Mosaic is on track to build about 350 customer frames by the end of this calendar year, with about 75% of them being full custom, and the remaining 25% consisting of “batch” build with stock geometry.
Another view of frames in production, on a nicely designed and built rack.
The folks at Mosaic aren’t just handy with titanium; apparently they’re pretty good with wood, too.
Several frames are shown in various stages of paint finish.
Mosaic is known for its titanium craftsmanship, but also for its finish work, particularly after purchasing Spectrum Powder Works in 2016. Hanging high up on one wall were a few frames sporting retired paint schemes.
A large bead-blasting machine sits in front of several others. The olive-green machine has two holes for an operator to put their hands in to move the frame around inside.
Mosaic has a room filled with media blasting stations for various finishing requirements.
A pile of tiny plastic beads for blasting shown held in someone's hand.
These plastic beads are used just to strip paint.
Justin Triplett sands a seatpost in paint prep.
A PRO carbon fiber seatpost is shown here getting prepped for paint by Mosaic employee Justin Triplett.
A computer controlled plot cutter churns out masks for paint designs.
Paint masks are cut on this plotter.
Cans and cans of paint, stacked on shelves.
So, what color do you want? The world is your oyster.
More paint, along with spray gun heads and a computer for mixing custom colors.
No, really, you really can pick just about any color you want.
Paint finishes like sparkles sit on a shelf along with tube samples.
Want some sparkle? Have at it.
More paint samples are shown, including stacks of options that can ship to dealers to show customers.
Mosaic – or, more specifically, its Spectrum Paint and Powder Works division – is constantly playing with different hues.
A large oven, shaped almost like an industrial refrigerator, for baking paint finishes.
I’m not sure I’d want to put a loaf of my bread into this oven.
Paint samples are laid out on a table to box and ship to dealers.
Paint samples getting organized for shipment to Mosaic dealers worldwide.
An empty paint booth with a frame "tree" and spray gun systems.
The paint booth has multiple stations to prevent bottlenecks.
Another empty booth, with a stand.
Where a different kind of magic happens.
Rows of painted frames hang on a rack, ready to be boxed and shipped.
Freshly painted, baked, and assembled frames, ready to be packed up and shipped out.
Clipboards with order sheets hang in a neat row.
Documentation is incredibly important to prevent costly errors.
A double shelving unit holds plastic boxes with all manner of small parts.
Headsets, seatpost collars, derailleur hangers, and other small fittings are kept here.
The rear triangle of a finished frame is shown, with through-axle and derailleur hanger already installed and even bolts for the disc brake.
Bolts for flat-mount brakes are included so there’s no question at the dealer what length needs to be used during the build process.
Boxes and boxes of different kind of forks sit stacked on shelving.
You think fully hidden routing is a pain for mechanics? Mosaic says its stock of forks basically doubled almost overnight since it offers both internal and external routing.
Various road and mountain bike forks sit disassembled ready for custom paint.
Dear Fox: please replicate this titanium paint finish and offer it stock.
What appears to be a bike order for a certain James Huang.
Oh hey, what do we have here?
Four large shipping boxes marked "Mosaic Bespoke Bicycles" sit with customer order sheets.
It may say “Bespoke Bicycles” on the box, but Mosaic only sells framesets; the rest is left to its international network of dealers. One nice upside for Mosaic is it can use the same size box for everything heading out the door.
A conventionally made rear disc brake mount shown next to a 3D printed model. Both are titanium, but the conventional one has a distinctive satin finish while the 3D one is a rough, grey matte.
Wondering why Mosaic doesn’t use any 3D printing? Well, the company is exploring the idea, but doesn’t feel the technology has enough to offer to justify the added cost. There’s also the not-so-small matter of the vastly different surface finish.
A closeup of rear dropouts, showing UDH-compatible fittings.
One new thing Mosaic has added already, though, is UDH-compatible rear dropouts.
A Honda CB360 motorcycle sits in a corner of the shop.
Craftspeople rarely have just a single interest. Barcheck said he traded a frame for this old motorcycle ages ago, but just hasn’t quite found the time to get it where he wants it to be. Sounds familiar.
Magnets with the Mosaic logo are attached to a fridge. The logo is a tree trunk with multiple branches.
Ever wonder where the Mosaic name and logo came from? “The idea behind the Mosaic name comes from the approach that we take with the company,” Barcheck explained. “There are many facets that are critically important to create high-quality crafted frames and rider experience, each one a profession to its own and no more or less important than the next (machining, welding, painting, bike fit, frame design, customer service, vision, etc.). When we strive for excellence in every way the individual components transform together, creating something greater, much like a mosaic. The tree headbadge is a symbol of connection that we all share through our cycling experience.”
Several demo bikes sit on the Mosaic shop floor, including a hardtail mountain bike. Behind are rows of paint chips.
Finding yourself in Boulder, Colorado any time soon? Hot tip: Mosaic has a demo fleet.
A closeup of a finished bottom bracket, with perfect TIG welds and a luscious bead-blasted raw finish.
Poetry in motion.
A gravel bike finished in a blue to red to orange fade.
This is the gravel bike Mosaic founder Aaron Barcheck used at Unbound Gravel earlier this year. Apparently, the bottom bracket is still seized.
An old bean grinder for coffee sits on a bench, along with a Chris King espresso tamper in orange.
Old school.
A row of liquors on a shelft, ranging from gin to bourbon, and a Mosaic-branded flask.
How do you know this is the liquor collection at a bicycle company? Look what else is there: energy drink mix and hot sauce.

What did you think of this story?