Peugeot PR10 Bike Frame Reynolds 531 3130g 57.5×57.5cm 122.3mm BFFF

The bottom bracket shell is cut to 35×100 mm — not BSC, not Italian — the thread that tells you this Peugeot PR10 was made at a time when French standards still ruled. That’s a boon for the restorer chasing period-correct parts, and it’s the first detail you check when a Reynolds 531 tubeset appears on the bench.

Why this PR10 stands apart

Reynolds 531 is the tubing that defined a generation, but the numbers here make the build path clear. Total mass tips the scales at 3130 grams with the fork. The fork steerer itself carries a 25×100 mm thread — another French hallmark. Rear dropout spacing sits at 122.3 mm, which aligns perfectly with 5-speed freewheels and threaded hubs. The frame is designed for 700C wheels (622 mm bead seat diameter), so modern rubber rolls on without hassle.

Technical specifications

• Material: Steel
• Bottom bracket thread: 35×100 “French”
• Fork steerer thread: 25×100
• Wheel size: 700C – 622 mm
• Country of origin: FRANCE

The paintwork shows significant wear — scuffs, chips, and areas of corrosion that the photos capture in full. That’s why the images are integral: they document exactly where the finish has failed and where the steel retains its integrity. No hidden surprises.

For a slightly larger sibling, the Peugeot PR10 58×57 cm frame shares the same French threading and Reynolds 531 pedigree. If you prefer a fully lugged PX10 version, the Peugeot PX10 PY10 56×57.5 cm frameset offers a slightly tighter rear end at 125.2 mm. Both keep the build strictly within the French ecosystem.