REG C 35x100 135mm Bottom Bracket for Vintage Eroica Bicycle BP17

French-Thread Bottom Bracket for Vintage Frames

The REG C unit answers a specific mechanical constraint on older steel frames: a 35x100 "Français" thread. This is not the more common BSC or Italian standard, so the cups must match the shell precisely. The axle measures 135 mm, a length that suits a range of vintage chainset layouts.

The shell is made of steel, as expected on a period-correct bottom bracket. The photos form part of the description: check the thread condition, the cup faces, and the axle surface before fitting. Minor cosmetic marks from storage may be present, but any major issue would be stated here.

Key Specifications

Key specifications

• Bottom bracket thread: 35x100 "Français"
• Material: Steel
• Country of origin: FRANCE
• Manufacturer part number: 0000

If you are building a vintage machine around French standards, a compatible cup set is essential. See also the STRONGLIGHT Bottom Bracket Left Cup 35x100 BP18 for a threaded cup alternative, or the STRONGLIGHT 35x100 French Thread Bottom Bracket 118mm Vintage Bike BP15 for a shorter axle in the same shell standard.

The 135 mm axle width remains a practical choice for classic cranksets where chainline and clearance matter. The French thread requires careful identification, so measure your shell width and thread pitch before fitting.