Heavy-duty steel bottom bracket shells - ISO threaded - 68.5mm and 73.5mm
sku # BBS-ISO-68.5, BBS-ISO-73.5 Made from seamless 4130 steel, these heavy-duty 39.7mm (outer diameter) ISO bicycle bottom bracket shells are available in 68.5mm and 73.5mm widths. Perfect for cargo bike applications or even as heat-distortion resistant shells for your first few builds. These BB shells are made with an extra .5mm of width ensuring sufficient material for facing both sides. At the end of the facing process, they will then be 68mm and 73mm respectively. Drive side can be identified by the slight gap/recess on the drive side before the threads begin. Even though these are heavy-duty, they are recessed on the inside to make them compatible with Paragon's heat-sinks. ISO aka BSA, BSC, BC, British, and Euro. Right and left threaded (ISO) 1.370" x 24tpi. 68.5mm - 150g 73.5mm - 160.5g Weights are based on representative samples. Actual weights may vary slightly. Imported.
HD 68.5mm ISO BB shell, HD 73.5mm ISO BB shell