Shimano Dura-Ace (GB-100) 1st Gen c.1972 Vintage English 112 mm Bottom Bracket 121 mm this is the most important

this is the most important measurement when checking the stem fits your bike

Weight - 795 g

Axle Length (D) - 112 mm

this is of the correct era

Stock Code - U-G3-CAS63V

Shimano Dura-Ace (GB-100) 1st Gen c.1972 Vintage English 112 mm Bottom Bracket 121 mm this is the most importantOriginal part produced in the 1970s Suitable for historic cycling events such as L'Eroica Professionally checked & cleaned Worldwide shipping Shimano Dura Ace bottom bracket (or BB for short), hailing from Japan and dating back to 1972. Made from steel and weighing in at 266 grams pretty lightweight for a BB at that time. A fine choice for keeping your vintage bike authentic, but also great for any other compatible bike. When the Dura Ace 7100 series