This mid-1970s classic road chassis represents classic French metallurgical craftsmanship. Built entirely from cold-drawn, double-butted Reynolds 531 alloy steel, this frame delivers the legendary mechanical compliance and road dampening that defined vintage steel racing eras. Sized at 56.5 cm (measured from the center of the bottom bracket to the top of the seat tube) by 57 cm (measured center-to-center along the top tube), this frame is ready for high-grade vintage restorations.
Technical Metallurgy & Alignment
Engineered for endurance and structural longevity, this frame is designed to handle classic road setups and is perfectly compliant with vintage events. The rear dropout spacing is configured at 122mm, accepting classic 5-speed or 6-speed hubs. It features a British/ISO/French thread standard (BSFF), ensuring excellent compatibility with period-correct bottom brackets. The structural weight of the assembly sits at exactly 2845g, including the fork, striking an optimal balance between weight efficiency and road vibration dampening. For restorers looking for alternative high-end French steel options, consider comparing this unit with our Peugeot PY10 Full Reynolds 531 frame or the slightly larger Peugeot PX10/PY10 60cm frame.
Technical Specifications
- Size: 56
- Seat Tube Height (A): 56.5 cm (BB center to top of seat tube)
- Top Tube Length (B): 57 cm (center-to-center)
- Total Weight: 2845g (frame and fork assembly)
- Rear Dropout Spacing: 122 mm
- Bottom Bracket Threading: BSFF
Structural Condition Notes
This is a pre-owned vintage component. The frame has been inspected for structural integrity. As an authentic piece of cycling history, it features its original paint and decals, which exhibit minor cosmetic wear and superficial storage marks. The high-resolution product photos act as the primary visual description for exact paint conditions, lug details, and decal preservation. No major structural defects, cracks, or alignment twists are present.
FAQ
What is the threading standard of this Motobecane C4 frame?
This frame features BSFF (British/ISO/French compatible) threads, making it straightforward to match with vintage bottom brackets.
What rear hub spacing does this frame require?
The rear dropout spacing is 122mm, which accommodates vintage 5-speed and 6-speed freewheel hubs.
What are the exact frame dimensions of this model?
The seat tube measures 56.5cm from the bottom bracket center to the top, and the top tube measures 57cm center-to-center.
