Frame Story - Bicycle Frames Long Term Design Research

Frame Story — Bicycle Design Research

Frame Story is an independent design research project initiated in 2012. Through the design, construction, repair, and use of experimental bicycle frames, the project examines how materials, joining methods, tools, and production conditions shape an object over time.

The work develops within the Tiny Factory, a home-based studio where designing, making, and daily riding form a continuous process. Each frame addresses a particular question. Bamboo and natural-fiber composites led to parametric connectors and distributed alignment systems. Reused textiles, cast epoxy junctions, CNC-machined interfaces, and handheld laser welding subsequently introduced different ways to organize construction.

The twenty-three frames documented here record this development through successive experiments. Failures, adjustments, and the limits of individual prototypes remain part of the research. The same practice informs The Human Machine, an academic design studio in which students design and build bicycles from the ground up.

The accompanying galleries reproduce the complete visual documentation from the two-part book draft, including process photographs, drawings, workshop layouts, and technical studies.

Frame 001

"The bicycle is the noblest invention of mankind." — William Saroyan

The Experimental Mobile Lab

Frame 001 was constructed as the first material experiment within the project, developed under conditions of limited access, minimal tooling, and limited prior knowledge. The frame combined bamboo tubes with cork and unwoven flax fibers, assembled using hand-applied composite techniques. The work was carried out without prior experience in composite bicycle construction and without access to specialized jigs or fabrication infrastructure.

The central question addressed by Frame 001 was whether natural materials could be combined into a structurally viable bicycle frame using low-cost, improvised manufacturing methods. Bamboo was selected for its availability, tensile strength, and shock-absorbing properties. Flax fibers were applied locally to reinforce joints and high-stress areas, while cork was introduced experimentally as an initial tube bridging. Their behavior was learned through direct application, use, and failure.

Component selection relied largely on salvaged parts recovered from discarded and decommissioned bicycles. Drivetrain elements, hubs, brakes, and auxiliary components were sourced through repair, disassembly, and reuse rather than procurement of new parts. This approach was driven by availability, cost constraints, and the practical logic of working within a closed material loop. Working with heterogeneous, previously used components introduced variability in tolerances, wear, and compatibility, influencing both construction decisions and subsequent adjustments.

Alignment and assembly were achieved using a makeshift jig constructed from a repurposed IKEA table and generic metal hardware intended for woodworking rather than frame building. This improvised setup imposed strict limitations on precision and repeatability, yet it allowed sufficient control to produce a rideable structure. Decisions regarding tube angles, joint thickness, and fiber orientation were made incrementally, often in response to visible deformation or material fatigue rather than predefined calculations.

The frame was configured for fixed-gear riding, intentionally exposing it to high torsional loads, abrupt braking forces, and repeated stress cycles. Riding functioned as an evaluation tool rather than a demonstration of performance. Flex, vibration, surface cracking, and joint behavior were monitored over time. Adjustments to fiber layering and joint geometry were carried out iteratively, sometimes mid-use, turning the bicycle into a mobile testing platform rather than a finished object.

Frame 001 did not resolve questions of durability, efficiency, or optimization. Instead, it made several conditions explicit: the sensitivity of natural composites to workmanship, the difficulty of achieving consistent structural behavior without controlled tooling, and the extent to which material behavior only becomes legible through extended use. The frame established a working baseline—not as a successful solution, but as a point of entry into material-driven inquiry where construction, use, and failure were inseparable.

Frame 002

"When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought of anything but the ride you are taking." — Arthur Conan Doyle

Hybrid Bamboo Construction and Digital Precision

Frame 002 marked a structural and methodological transition within the project. It introduced parametric thinking and desktop digital fabrication as integral parts of the construction logic. Building on the bamboo framework developed previously, this iteration incorporated 3D-printed connectors produced via fused deposition modeling. At this stage, the parts were fabricated externally on an early-generation PRUSA printer, when desktop additive manufacturing was still emerging. The printed nodes functioned as controlled geometric interfaces, compensating for natural variation in bamboo and allowing precision to be concentrated at connection points rather than imposed across the entire structure.

The shift to digitally defined joints coincided with the development of a rigid alignment system based on modular aluminum extrusion profiles. This aluminum jig significantly improved geometric accuracy and repeatability, establishing a more stable relationship between design intent and fabrication outcome. For the first time, geometry, connectors, and alignment were coordinated within a unified parametric framework.

This frame also introduced purpose-designed aluminum components manufactured through laser cutting and machining, including dedicated dropouts and a bottom bracket shell. These parts were conceived specifically for the frame rather than adapted from existing bicycles, enabling tighter tolerances and clearer load management at critical interfaces. The braking system transitioned to disc brakes, requiring structural reconsideration of the rear triangle and fork area to accommodate torsional loads and mounting standards.

Material strategy evolved as well. The composite joints were constructed using fiberglass as a structural underlayer, over which hemp fiber saturated in epoxy was applied. This marked a transition toward hemp-based reinforcement as the primary natural fiber system. The lamination logic extended beyond the main triangle to additional components, including a bamboo fork, an integrated handlebar–stem unit, and seating elements. These explorations tested whether the hybrid system of bamboo, composite reinforcement, and digitally defined nodes could support bending, torsion, and ergonomic loads across multiple parts of the bicycle.

Frame 002 established a more deliberate integration between craft and controlled fabrication. Digital tools stabilized geometric uncertainty, aluminum interfaces introduced standardized tolerances, and hemp-based composites refined the material system. The result was not simply a more precise frame, but the emergence of a coordinated production logic that would inform subsequent developments.

Frame 003

"Bicycling is a big part of the future. It has to be. There’s something wrong with a society that drives a car to work out in a gym." — Bill Nye

Parametric Modularity with Hemp–Epoxy Composites

Frame 003 marked a decisive shift in the project. It was the first frame built after acquiring a personal desktop 3D printer, a change that fundamentally altered the working process. The ability to design, print, test, and revise components in rapid succession closed the gap between idea and fabrication. Iteration became immediate rather than deferred, and both the frame and the jig evolved in parallel.

This frame was produced as a commissioned project, providing a concrete context to test personalization as a functional requirement rather than a speculative concept. Parametric design principles were used to control frame geometry through adjustable variables such as tube angles, lengths, and diameters. These parameters were translated directly into 3D-printed jig elements, allowing the alignment system to be reconfigured quickly in response to rider-specific constraints.

The frame combined bamboo poles with hemp fiber–epoxy composite joints. Hemp fibers were selected for their tensile strength and flexibility, reinforcing critical connection points while improving vibration damping. Material choices were evaluated not only for mechanical performance, but for their compatibility with a workflow based on rapid iteration and low infrastructural overhead.

The operational accessibility introduced by in-house additive manufacturing changed the rules of the process. The jig was no longer a fixed tool but a mutable system, refined through use. Decisions could be tested physically within hours rather than weeks, enabling a level of precision and adaptability that had not been possible in earlier frames.

As a commissioned build, Frame 003 functioned as a proof of feasibility. It demonstrated that meaningful product personalization could be achieved within an independent, small-scale production environment by aligning parametric design, material behavior, and fabrication logic. The modular jig system developed here became a reference point for subsequent frames, establishing iteration itself as a core design instrument.

Frame 004

"Think of bicycles as rideable art that can just about save the world." — Grant Petersen

One-Sided Alignment and Integrated Cable Routing

Frame 004 marked a structural consolidation rather than an experimental departure. After three previous frames, the central shift was not conceptual but operational: the development of a new one-sided jig and a clearer integration of cable routing within the lugs themselves.

The one-sided jig improved access during lamination, allowed more precise fiber placement, and stabilized alignment without obstructing the working area. This adjustment reduced production time and increased repeatability, especially in joint transitions where material buildup directly affected geometry.

Cable routing was no longer external, nor did it rely on separate braze-ons formed from epoxy and chopped fibers. Instead, cables passed directly through the lugs. This eliminated additional attachments and preserved structural continuity without adding secondary elements. The routing strategy became part of the joint architecture rather than an accessory.

Connection zones were thickened selectively according to rider dimensions and intended use. Areas subjected to higher stress—bottom bracket, head tube cluster, and rear junctions—were defined parametrically based on rider weight, riding style, and terrain. Lamination density followed functional demand rather than visual preference.

The bicycle was initially built as a single-speed platform, with dropout geometry and spacing designed to allow future drivetrain upgrades. A decade later, this latent capacity was realized when the frame was converted to a multi-speed configuration, confirming that structural foresight had been embedded from the beginning.

Frame 005

"Every time I see an adult on a bicycle, I no longer despair for the future of the human race." — H.G. Wells

Travel-Friendly Knockdown Frame

Frame 005 addressed the logistical constraints of international bicycle travel, specifically airline baggage limitations. The frame was designed as a knockdown system capable of being partially disassembled to fit inside a standard suitcase under 60 cm in length, avoiding oversized luggage handling.

The structural solution relied on four coupler interfaces located exclusively in the rear triangle: two at the chainstays and two at the seatstays. These couplers allowed the rear triangle to detach while preserving the integrity of the main triangle. Their placement required precise control over alignment and tolerance, as each interface had to maintain dropout spacing, axle alignment, and overall rear-end geometry after repeated assembly cycles.

The couplers were treated as structural junctions integrated into the composite logic of the frame rather than as external hardware additions. Reinforcement around these zones was locally increased according to rider dimensions and intended use, ensuring that load transfer across the segmented areas remained continuous under pedaling and braking forces.

The frame underwent repeated riding and disassembly cycles to verify that the four rear coupler points maintained structural consistency over time. The project phase focused on validating whether segmentation could be introduced selectively—limited to the rear triangle—without compromising handling or durability.

Frame 006

"When I got the bike I must have been the happiest boy in Liverpool, maybe the world." — John Lennon

Process Consolidation

Frame 006 did not introduce a structural shift. The geometry remained consistent with the previous iteration, and the overall construction logic stayed intact. The changes were incremental and process-driven rather than conceptual.

The primary development was improved control over manual execution. Fiber wrapping became more precise, with better consistency in tension, overlap, and orientation. Resin ratios were measured more carefully, reducing excess epoxy and improving fiber-to-resin balance. Bonding areas were handled with greater accuracy, resulting in cleaner junctions and fewer post-cure corrections.

At the same time, more attention was given to component selection and visual coherence. Parts were chosen with greater care, and color coordination became more deliberate, moving toward a quieter and more refined presence without altering the underlying structure.

This stage reflects consolidation rather than experimentation—less novelty, more control. It represents a period of technical maturation just before the next structural or engineering challenge.

Frame 007

"The advantages? Exercise, no parking problems, gas prices, it’s fun. An automobile is expensive. You have to find a place to park, and it’s not fun. So why not ride a bicycle? I recommend it." — Stephen G. Breyer

Symmetrical Modular Frame

Frame 007 continued the modular investigation introduced in Frame 005, but refined the concept into a more symmetrical breakdown structure. While Frame 005 addressed travel constraints through segmentation of the rear triangle, Frame 007 introduced couplers directly into the top tube and down tube, allowing the main triangle itself to separate into balanced segments. This resulted in a more even structural division and a clearer assembly logic.

The frame was built as a single speed platform. The reduced drivetrain complexity allowed attention to focus on structural behavior and modular precision rather than component integration. The couplers were positioned to maintain alignment consistency while enabling controlled disassembly. Their placement required careful management of tolerances and bonding interfaces to avoid stress concentration around the joints.

A new jig was developed specifically for this iteration. Its primary feature was the ability to split into two independent sections. This allowed easier access to each half of the frame during layup and bonding, improving ergonomics and workflow efficiency. The jig was also simplified, using significantly fewer aluminum profiles than previous versions. The reduction in structural members did not compromise alignment accuracy but made handling and storage more practical.

To compensate for the structural interruption created by the couplers, an additional bamboo tube was added between the top tube and down tube. This secondary brace increased torsional stiffness within the main triangle and redistributed loads across the front section of the frame. It functioned as reinforcement rather than as a formal gesture.

The frame geometry also considered practical daily use. Mounting points were incorporated to allow straightforward installation of a rear rack for carrying a child seat or cargo. This extended the frame’s utility beyond modular travel considerations and positioned it within everyday functional use.

Frame 007 represents a stage of consolidation rather than radical change. It refined the modular logic introduced earlier, simplified tooling, and improved structural clarity while maintaining the material and construction language established in previous iterations.

Frame 008

"Work to eat. Eat to live. Live to bike. Bike to work." — Unknown

Modular, Size-Adaptive Structure

Frame 008 marked the final stage of a chapter centered on improvisation, structural experimentation, and a deeper technical understanding of bicycle systems before moving toward a more formalized methodology.

The frame was conceived as a size-adaptive structure capable of accommodating riders approximately 140–185 cm in height (roughly 47–57 cm equivalent frame sizes). Rather than resizing a fixed geometry, the structure itself changed proportionally according to rider dimensions. As a direct consequence of this variable architecture, the frame once again became modular and detachable—though its connection logic differed entirely from Frames 005 and 007.

The construction was based on four primary structural modules composed of 3D-printed interfaces, aluminum connectors, and wooden poles reinforced with 100% cotton fiber laminates. Quick-release mechanical joints allowed the frame to be disassembled into compact segments. Unlike earlier modular attempts, the breakdown principle here was derived from geometric variability rather than travel constraints.

A stainless-steel high-tension cable replaced the conventional down tube. This cable operated in tension, stabilizing the structure while reducing material mass and allowing controlled flexibility. The parallel arrangement of the upper and lower structural members contributed to load distribution and simplified dimensional adjustments.

A significant methodological development during this phase was the introduction of a microstructure jig system. Instead of relying on a single large fixture, each structural unit was fabricated within its own small-scale jig. These independent jigs allowed precise control over local geometry while maintaining flexibility for dimensional variation. The modules were later assembled into a complete frame, demonstrating a shift toward distributed alignment logic rather than centralized constraint.

In practice, the bicycle accumulated only a limited number of kilometers. It functioned primarily as an experimental platform rather than a long-term riding solution. Structurally and conceptually, however, it became a bridge toward the next series of frames, where several ideas introduced here—modular interfaces, distributed jigs, and adaptable geometry—were refined and developed further.

Frame 009

"The best rides are the ones where you bite off much more than you can chew, and live through it." — Doug Bradbury

Jigless Construction and Denim Composite Lugs

Frame 009 marked a decisive step in redefining how bicycle frames could be constructed outside the constraints of traditional fixed jigs. This iteration introduced the Jigless Kit as an experimental system aimed at decentralizing framebuilding and lowering the infrastructural threshold required for precision fabrication.

Conventional frame jigs ensure alignment and repeatability, yet they also impose geometric rigidity and demand significant investment. Frame 009 proposed an alternative logic: instead of relying on a singular, heavy fixture, alignment was achieved through a set of parametric 3D-printed components functioning as temporary micro-fixtures. These elements were designed digitally and produced on demand, allowing tube positioning to be customized per geometry without retooling an entire jig system.

The frame itself was constructed from aluminum tubes, selected for their structural efficiency and suitability for iterative prototyping. Geometry could be modified at the file level, and updated alignment components could be printed locally. This shifted precision control from hardware to digital parameters. The jig became distributed—composed of multiple adjustable parts rather than a fixed, monolithic structure.

Beyond structural methodology, Frame 009 continued material experimentation. Critical joints were reinforced with laminated fibers derived from recycled denim. The choice reflected an ongoing investigation into accessible, locally sourced reinforcement strategies. While long-term durability remained under evaluation, the approach emphasized material availability, adaptability, and the potential integration of circular material streams into frame construction.

Field tests indicated that the frame maintained acceptable alignment and functional stability under riding conditions. However, joint refinement and tolerance calibration required further development, underscoring the experimental status of the method. Frame 009 did not present a finalized industrial solution; rather, it operated as a research platform for testing flexibility, modular alignment, and decentralized fabrication logic.

As part of the broader research trajectory, the Jigless Kit established an important conceptual shift. Framebuilding was reframed from a fixed-fixture craft toward a parametric, shareable system. The possibility of distributing jig component files opened a pathway toward collaborative modification and global iteration. Frame 009 thus laid foundational groundwork for subsequent explorations in repeatability, protocol definition, and accessible production models.

Frame 010

"If constellations had been named in the 20th century, I suppose we would see bicycles." — Carl Sagan

Refining Aluminum–Composite Interfaces

Frame 010 is a direct continuation of Frame 009 and should be read as a corrective iteration rather than a conceptual leap. Following the structural failure identified in Frame 009—specifically the detachment between aluminum tubes and the laminated fiber lugs—this version introduces minor but critical refinements.

The primary adjustment is the reintroduction of a wooden dowel inserted into the aluminum tubes. This internal reinforcement improves mechanical interlock and reduces the risk of delamination between the aluminum surface and the denim-epoxy composite. Surface preparation and overlap logic were also reconsidered, though the overall construction language remains consistent with the previous frame.

The rear end transitions to a single-speed dropout configuration with disc brake compatibility and an integrated chain tensioner, referencing structural decisions previously explored in Frame 004.

This chapter is intentionally brief. Frame 010 is less about formal experimentation and more about method consolidation—clarifying bonding strategy, structural logic, and system integration derived directly from the lessons of Frame 009.

Frame 011

"A bicycle ride is a flight from sadness." — James E. Starrs

Modular Material Experiments

Frame 011 continues the structural logic developed in Frame 009, maintaining the hybrid construction of aluminum tubes and laminated fiber lugs. A wooden dowel was reintroduced inside the tube interfaces to improve mechanical interlocking and reduce the risk of separation between aluminum and composite joints.

This iteration was designed to be taken apart, allowing controlled testing of different riding parameters resulting from material changes in the top and down tubes. The modular configuration was intended to enable comparison of stiffness, vibration behavior, and overall ride characteristics without rebuilding the entire structure.

A denim saddle and matching seatpost were developed as part of the broader material exploration. The handlebar was conceived as a detachable unit with an integrated stem and front light, extending the investigation into component-level modularity.

This bicycle was developed as an artist concept. In practice, the bicycle was never fully tested on the road. The project functioned as a structural and conceptual prototype rather than a finalized riding platform. Some of the principles explored here—particularly joint reinforcement, modular segmentation, and hybrid material interfaces—continued into subsequent frames. Not every experiment needs to be validated through mileage; in this case, the value lies in the ideas carried forward.

Frame 012

"You don’t suffer, kill yourself, and take the risks I take just for money. I love bicycling." — Greg LeMond

Fiber Lamination with Used Military Uniforms

Frame 012 continued the aggressive single-speed road geometry used in the following sequence of frames, maintaining the negative-sloping top tube and identical core dimensions in order to isolate fabrication variables from geometric change.

This frame incorporated used military uniforms into the laminated lug structure. The textile was embedded within the fiber layers rather than applied as surface decoration. Because cotton-based fabric absorbs resin unevenly, additional structural reinforcement was added in high-stress zones to maintain stiffness at the head tube and bottom bracket junctions. The lamination schedule was adjusted accordingly. The use of recycled textile introduced variability in thickness and surface finish. Some seams required sanding after cure to maintain continuity across the lug transitions. Cable routing remained external to avoid unnecessary interruption of the composite zones. Frame 012 did not introduce a new structural principle. It consolidated earlier lamination methods while testing how non-standard textiles behave inside load-bearing joints. The result was structurally stable, though fabrication required tighter control and longer finishing time.

Frame 013

"Life is like riding a bicycle. In order to keep your balance, you must keep moving." — Albert Einstein

Reused Textiles and Laminated Lugs

Frame 013 continued the investigation of reused textiles within laminated composite lugs. Aluminum tubes were joined using natural and synthetic fabric remnants, with changes in color, pattern, and material becoming part of the construction itself.

The frame used the vertical jigless method, combining parametric 3D-printed alignment components with standard hardware. Maintaining this assembly logic allowed attention to move toward the behavior and appearance of different fabrics in the laminate. The accompanying images document these material and surface experiments.

Frame 014

"The bicycle is just as good company as most husbands and, when it gets old and shabby, a woman can dispose of it and get a new one without shocking the entire community." — Ann Strong

Quilting Remnants and Composite Surfaces

Frame 014 extended the textile experiments of Frame 013 through the use of quilting remnants. Natural and synthetic fabrics were incorporated into composite junctions around aluminum tubes, producing layered surfaces whose appearance followed the placement and finishing of the cloth.

The frame retained the vertical jigless assembly method, using parametric 3D-printed parts and standard hardware to position the tubes. Frames 013 and 014 form a related material study: reused textiles affect the surface of the object while remaining embedded within its construction.

Frame 015

"The bicycle is a curious vehicle. Its passenger is its engine." — John Howard

Flax Fiber Ribbons and Integrated Exhibition Mounting

Frame 015 continued the lamination work using red flax fiber ribbons as a primary structural material. The geometry remained consistent with the preceding sequence in order to isolate material and structural adjustments from dimensional change.

Brass tubes were embedded within the frame during construction. Their purpose was to allow the bicycle to be suspended using steel cables during exhibition display. The suspension logic was integrated into the structure itself rather than added as external hardware.

The same vertical jig configuration introduced in Frame 012 was used here, with minor refinements for positioning and clamping. No new assembly principle was introduced. The structural layout followed the established sequence.

Cable routing remained external.

Frame 015 was presented suspended, using the integrated brass tubes as anchor points. The frame was built to function as a rideable structure while also accommodating exhibition conditions without additional display components.

The bicycle was presented at Taipei Design Week.

Frame 016

"Give a man a fish and feed him for a day. Teach a man to fish and feed him for a lifetime. Teach a man to cycle and he will realize fishing is stupid and boring." — Desmond Tutu

The Pajama Methodology

Frame 016 was built under what I later referred to as the Pajama Methodology. The premise was simple: the entire frame would be designed, sourced, and assembled without leaving the workshop. No industrial visits, no local suppliers, no physical scouting of materials. All components—carbon fiber sheets, titanium couplers, hardware, small fittings—were ordered through online marketplaces, primarily AliExpress, often relying on free international shipping.

This constraint shaped the project more than the geometry did. Material selection was limited to what could be found, compared, and evaluated remotely. Lead times were unpredictable. Some parts arrived within two weeks; others required reordering due to dimensional inaccuracies. Tolerances listed online did not always match delivered parts. As a result, bonding gaps and interface thickness had to be recalculated after physical measurement rather than assumed from specification sheets.

The frame marked the project’s first full carbon fiber construction. Layup was performed around composite tube sections rather than metal cores. Junction zones at the head tube and bottom bracket required additional reinforcement after early flex testing revealed localized softness. This build depended on fiber orientation and layer schedule for stiffness control.

Titanium couplers were integrated into the top and down tubes, allowing the frame to be separated. Because the couplers were sourced remotely, dimensional verification occurred only after arrival. Minor inconsistencies in machining required careful alignment during bonding to prevent angular deviation at reassembly.

A rear shock element was incorporated, introducing a new load path through the seat cluster. Mounting zones were reinforced locally after dry assembly revealed slight compression under preload.

The entire build depended on global logistics, online sourcing, and free-shipping supply chains. The method reduced direct industrial interaction but increased the burden of verification, adjustment, and adaptation at the workshop level.

Frame 017

"The bicycle has done more for the emancipation of women than anything else in the world." — Susan B. Anthony

Orthopedic Casting Tape

Frame 017 began with a practical observation in an orthopedic clinic. Casting tape—used to immobilize fractures—was being applied in layered wraps that hardened quickly without extended curing time. The material was lightweight, flexible during application, and rigid once set. A small batch was ordered to test whether it could function as a structural connector in a bicycle frame. The tape replaced conventional epoxy-based laminates at selected joints. Tubes were dry-positioned, wrapped directly, and compressed by hand during curing. Hardening occurred within minutes. This reduced build time significantly compared to earlier composite layups, which required staged curing and post-processing.

The material behaved differently from traditional fiber laminates. The woven structure was less dense and produced a porous surface once cured. Additional wrapping was required at high-load zones, particularly at the bottom bracket cluster, to control flex. Early manual load tests indicated noticeable compliance compared to previous builds. Whether this translated into ride comfort required evaluation beyond static testing. Bright-colored tape was used without overpainting, exposing the material’s origin. The surface remained textured. No attempt was made to conceal it under filler or paint. The experiment was about aesthetic variation, speed of application, reduction of tooling, and testing whether a medical composite could function under cycling loads. The result was structurally usable but less precise in tolerance control than epoxy-based laminates. Joint geometry depended heavily on hand pressure during wrapping. Frame 017 extended the material inquiry beyond conventional composite practice. It introduced a fast-setting structural method with clear limits in stiffness control and surface finish. Whether the material would sustain long-term fatigue under riding conditions remained an open question.

Frame 018

"Cyclers see considerably more of this beautiful world than any other class of citizens. A good bicycle, well applied, will cure most ills this flesh is heir to." — Dr. K. K. Doty

Cast Epoxy Junctions

Frame 018 departed from fiber-based reinforcement entirely. No woven or textile layers were used. Instead, epoxy was cast directly into the junction nodes, forming solid connection masses between tubes. The intention was to test passive damping through material bulk rather than through laminate orientation.

The tubes were dry-aligned and mechanically fixed in position before epoxy casting. Temporary molds were built around each junction to contain the resin during curing. Because casting generates heat during polymerization, volume had to be controlled. Early pours revealed excessive exothermic reaction in thicker sections, leading to surface cracking. Subsequent joints were cast in stages to reduce thermal stress.

The concept was simple: create joint zones that behave more like cartilage than rigid composite shells. The cured epoxy formed dense, slightly compliant nodes. Unlike fiber laminates, these cast joints did not rely on directional reinforcement. Their behavior depended on resin volume, joint geometry, and bonding quality.

Frame 019

"Bicycles may change, but cycling is timeless." — Zapata Espinoza

Controlling Resin Volume and Mold Geometry

Frame 019 continued the cast-epoxy joint methodology introduced in Frame 018. The geometry remained constant in order to isolate joint behavior as the primary variable. No fiber reinforcement was used. The structural nodes were formed by casting epoxy directly around mechanically aligned tubes.

The main adjustment concerned joint volume and boundary control. In Frame 018, the epoxy masses were relatively thick, resulting in localized heat buildup during curing and minor surface cracking. In Frame 019, the joint cavities were redesigned to reduce resin volume and improve heat dissipation. Casting was performed in controlled layers rather than single pours. This reduced exothermic stress and improved surface stability.

Mold design was refined. Instead of improvised containment forms, more precise temporary shells were fabricated to control edge geometry and resin overflow. This improved repeatability between junctions and reduced post-cure shaping time.

Manual torsion and compression tests suggested improved joint stiffness compared with Frame 018. Compliance at the nodes remained part of the investigation, alongside control of voids and surface defects.

Frame 019 did not introduce a new structural principle. It corrected casting technique, heat management, and mold accuracy. The experiment moved from exploratory casting toward controlled implementation.

Frame 020

"Ride as much or as little, or as long or as short as you feel. But ride." — Eddy Merckx

Surface Preparation and Bonding Reliability

Frame 020 maintained the cast-epoxy joint strategy but shifted focus to interface preparation and bonding reliability. Previous iterations revealed that adhesion between aluminum tube surfaces and solid epoxy mass depended heavily on surface treatment consistency.

For this build, aluminum tube ends were aggressively roughened and degreased prior to casting. Mechanical scoring was introduced to increase surface keying. Joint cavities were designed to include shallow internal ridges, allowing the cured epoxy to mechanically lock into the tube interface rather than relying solely on adhesion.

Casting thickness was further reduced. Instead of large node masses, the epoxy was distributed more strategically around stress paths. This reduced overall joint weight and improved visual integration with the tube structure. Cure sequencing was adjusted to allow partial gelation before final fill, minimizing sagging and edge distortion.

Initial load tests indicated more stable interface behavior compared to Frames 018 and 019. No immediate delamination was observed under manual torsion. Joint stiffness and compliance continued to be evaluated through use.

Frame 020 concluded the cast-joint series. The method proved feasible within defined limits but required careful control of volume, surface preparation, and curing sequence. The series established a basis for further investigation of cast joints, with weight and long-term fatigue performance remaining open questions.

Frame 022

BEAM — Laser Welding in the Tiny Factory

Frame 022, BEAM, investigates how handheld laser welding can become part of a compact, independent bicycle-building workshop. The frame combines aluminum square profiles, laser-cut parts, and CNC-machined interfaces within a beam-based structure intended for touring and bikepacking.

The beam provides both a structural member and usable internal volume. Four integrated storage compartments and multiple attachment interfaces explore how the frame itself can accommodate equipment. Printed fixtures, cutting templates, and modular alignment tools support the transition from digital drawings to fabrication.

Developing this first BEAM prototype also required building the production environment. The book documents equipment layout on the home balcony, the welding setup, material trials, fit-up, and the preparation of the head tube, seat tube, and other interfaces. Aluminum welding became a process to learn through successive parts and assemblies.

The research concerns the conditions of production as much as the completed bicycle: which operations can be brought into the Tiny Factory, which still depend on external suppliers, and how design decisions respond to the tools and materials available.

Frame 023

BEAM — Selective Reinforcement and Integrated Functions

Frame 023 develops directly from the conclusions of Frame 022. Its principal adjustment is selective reinforcement: aluminum patches locally thicken connection areas, supporting joint stiffness and the welding of square profiles without increasing material throughout the frame.

The flat faces of the profiles function as active interfaces. The documented variations explore a carrying handle, a vase within the frame, and integrated front and rear lighting. These functions develop from the structure and its available surfaces. A beam can combine storage volume, a light housing, rack support, and a mudguard within the same component.

The vase version introduces the transport of a single flower into an everyday urban bicycle. This small gesture sits alongside the technical investigation of fit-up, alignment, and local reinforcement, extending the relationship between structure and use.

Compared with Frame 022, this iteration followed an established workshop setup and a more familiar production sequence. It examines how accumulated process knowledge can shorten the path from design to fabrication, while the prototype continues to inform subsequent development of the BEAM system.

Technical Studies & Pedagogy

Drawings and process studies from the book’s teaching and technical sections.

Bicycle Geometry

Components & Systems

Materials, Fabrication & Rider Fit

Bicycle Typologies

Process Archive

Early films and project pages retain the frame numbering used when they were made.

18 years without a car, facts and figures