Konno’s Cherubim R2: A Master Class in Lugged Steel Construction

The Build: When Toronto Meets Tokyo

This Cherubim R2 represents what happens when a discerning cyclist seeks something beyond mass production. Built by Shin-Ichi Konno in his Machida, Tokyo workshop, this particular frame showcases the technical excellence that earned Cherubim its reputation among steel frame enthusiasts.

The client, Ali, already owned an Italian race bike but wanted something different—specifically, a lugged steel frame with exceptional craftsmanship. Toronto’s Blacksmith Cycle facilitated the build, conducting the initial fit session and coordinating with Konno’s workshop to ensure precise geometry tailored to Ali’s measurements.

Understanding the R2 Model

The R2 sits within Cherubim’s four-model lineup as the brand’s showcase for traditional lugged construction. Unlike the aerodynamic Racer, the all-around Sticky road bike, or the track-specific Triple Crown, the R2 emphasizes classic building techniques while maintaining modern performance standards.

Konno constructs the R2 using thinned and polished lugs—a labor-intensive process where each lug is hand-filed to remove excess material while maintaining structural integrity. This technique, largely abandoned by production manufacturers, creates smooth transitions between tubes that distribute stress more evenly than welded joints. The visual result is equally impressive, with each joint appearing as a seamless blend of intersecting tubes.

Frame Construction and Materials

This R2 utilizes Kaisei steel tubing, a Japanese-manufactured tubeset known for its consistent quality and ride characteristics. Kaisei offers multiple wall thicknesses and diameters, allowing Konno to select specific tubes for each frame section based on the rider’s weight, riding style, and intended use. For those interested in steel frame maintenance, Park Tool’s FR-5.2 cassette tool and Finish Line’s frame saver are essential for preventing internal rust—a critical consideration for steel frames.

The frame pairs with a custom Columbus MAX Aero fork featuring a 1-inch threaded steerer. This fork choice maintains period-correct aesthetics while providing the lateral stiffness needed for precise handling. The oval-profile fork blades reduce aerodynamic drag compared to round blades, offering a measurable performance advantage without compromising the classic appearance.

Component Selection and Integration

The build specification reads like a collaboration between Japanese and Italian component manufacturers. Nitto, another storied Japanese company, provided custom pantographed components including the stem, seatpost, and handlebars. These Cherubim-branded pieces aren’t merely aesthetic choices—Nitto’s reputation for precise tolerances and consistent clamping force makes them ideal partners for a frame of this caliber. Cyclists building similar projects should consider Nitto’s standard production stems as more accessible alternatives.

The drivetrain centers on Campagnolo Super Record components, specifically the Ergopower brake/shift levers that represent the pinnacle of mechanical shifting. These levers offer multiple hand positions and allow shifting from both the hoods and drops—crucial for maintaining control during aggressive riding. The Campagnolo cable sets designed for these systems ensure optimal shifting performance.

Ali selected a Fizik Arione 00 saddle, a model featuring a carbon-reinforced shell and Mobius carbon rails. This saddle’s flat profile and minimal padding suit riders who maintain a aggressive position, distributing weight evenly across the sit bones. For riders seeking similar performance at a lower price point, the Fizik Arione R3 offers comparable shape with alloy rails.

Wheelset and Rolling Stock

The 35mm-deep Campagnolo Bora One clincher wheels represent a significant performance investment. These carbon wheels weigh approximately 1,405 grams per pair while maintaining the stiffness required for power transfer. The clincher format was a practical choice, eliminating the complexity of tubular tires while allowing for easy roadside repairs.

Continental tires complete the package, though the specific model wasn’t detailed. Given the build’s performance orientation, Continental Grand Prix 5000 tires would be the logical choice. These tires balance low rolling resistance with puncture protection—essential qualities for a bike intended for regular use. Home mechanics should keep Pedro’s tire levers and a quality floor pump with gauge for proper tire maintenance.

The Konno Workshop Process

Cherubim operates as the boutique division of Konno Cycle Works, founded by Shin-Ichi’s father in 1965. The workshop gained international recognition when Konno’s Silver Flyer track bike won both Best in Show and President’s Choice at the 2012 North American Handmade Bicycle Show—validation of his technical capabilities despite criticism that some show bikes prioritize form over function.

The ordering process for this R2 began with Blacksmith Cycle conducting a comprehensive bike fit. These measurements determined not just frame size but also tube angles, bottom bracket drop, and chain stay length. Each dimension affects handling characteristics: steeper head angles quicken steering response, while longer chain stays improve stability. Konno uses these specifications to create a frame that matches the rider’s physiology and preferences.

Technical Details Worth Noting

Several technical aspects distinguish this build from production bicycles. The 1-inch threaded headset, while considered obsolete by many, offers advantages for steel frames. The threaded system distributes load across a larger area than modern threadless designs, reducing stress on the head tube. Quality 1-inch headsets from Chris King remain available for similar builds.

The pantographed Nitto components deserve additional attention. Pantographing involves removing material from components to create recessed logos or designs. This process requires precise milling to avoid compromising structural integrity. The resulting components are lighter than standard versions while displaying the builder’s brand—a detail appreciated by collectors and enthusiasts.

Practical Considerations for Ownership

Owning a custom steel frame like this R2 requires specific maintenance practices. Steel’s susceptibility to rust demands regular inspection and preventive care. Boeshield T-9 lubricant provides excellent corrosion protection for exposed steel, while J.P. Weigle’s Frame Saver treats internal surfaces.

The investment in a Cherubim frame extends beyond the initial purchase. Proper storage requires a quality work stand to avoid clamping the thin-walled tubes. Climate-controlled storage prevents condensation that leads to rust. Regular cleaning with appropriate bicycle cleaners maintains both appearance and longevity.

The Broader Context

While Shin-Ichi built this frame, his family’s influence extends throughout Japanese cycling. His brothers founded 3Rensho and Miyuki, creating three NJS-certified brands within one family. NJS certification allows frames to be used in keirin racing, where equipment standards exceed typical consumer requirements. This certification, now overseen by the JKA Foundation rather than the original Nihon Jitensha Shinkōkai, validates the structural integrity and consistency required for professional racing.

Cherubim offers the R2 in both standard Kaisei steel and stainless steel options. The stainless variant can be mirror-polished, creating a maintenance-free finish that never requires paint. This option adds significant cost and production time but results in a frame that maintains its appearance indefinitely with minimal care.

Assessing the Complete Build

This particular R2 succeeds as both a performance machine and a demonstration of traditional craftsmanship. The component selection balances heritage (threaded headset, Nitto cockpit) with modern performance (carbon wheels, Super Record drivetrain). The result is a bicycle that performs at contemporary standards while maintaining the ride quality and aesthetics that make steel frames desirable.

For Ali, this represents a significant upgrade from his previous Italian race bike. The custom geometry ensures optimal fit, while the steel construction provides a different ride quality than carbon or aluminum. Steel’s natural damping characteristics reduce road vibration, particularly beneficial on longer rides or rough pavement.

The total investment for a build of this caliber typically exceeds $10,000, with the frame alone commanding $4,000-6,000. Add the Campagnolo Super Record gruppo, Bora wheels, and custom finishing, and the price reflects the exclusivity and craftsmanship involved. For context, a complete Campagnolo Super Record groupset currently retails for approximately $4,000.

Long-Term Value Proposition

Unlike mass-produced frames that depreciate rapidly, custom steel frames from recognized builders maintain or increase in value. The limited production numbers—Konno produces perhaps 20-30 frames annually—ensures rarity. The combination of provenance, craftsmanship, and usability creates a compelling ownership proposition for serious cyclists.

This R2 will likely outlast its carbon contemporaries by decades. Steel frames can be repaired if damaged, repainted when worn, and modified if needs change. The tools required for basic maintenance represent a modest investment compared to the frame’s value. With proper care, this bicycle becomes an heirloom piece, rideable for generations.

The collaboration between Blacksmith Cycle and Konno’s workshop demonstrates the value of experienced intermediaries in custom projects. Direct ordering from Japanese workshops presents language and cultural barriers. Established relationships ensure clear communication about specifications and expectations, reducing the possibility of expensive misunderstandings.

Essential Gear for Steel Frame Enthusiasts

For those inspired by this beautiful Cherubim build, here are some essential items to maintain and enjoy your own steel frame bicycle:

• Park Tool Frame and Fork Maintenance Kit – Essential tools for proper steel frame care
• Silca Frame Pump – Classic Italian pumps that complement vintage aesthetics
• Brooks Leather Saddles – Traditional saddles perfect for steel frames
• Chris King Headsets – Premium headsets for threaded forks
• White Industries Components – American-made parts that pair well with custom frames
• Pedro’s Bike Care Products – Professional-grade maintenance supplies
• Velotoze Shoe Covers – Protect your vintage build from the elements
• Japanese Bicycle Design Books – Learn more about Japanese frame building culture

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