Shimano UN55 English SQUARE-JIS 73x110mm Bottom Bracket compatio_raw while the transition knobs and

while the transition knobs and raised side lugs are spaced out to provide cornering traction and shed debris

The chrome hardened pin construction provides longer chain life

2mm thick sides

Four years later in 1988

WARNING Handling this product will expose you to chemicals

Shimano UN55 English SQUARE-JIS 73x110mm Bottom Bracket compatio_raw while the transition knobs andShimano's BB UN55 Square Spindle Bottom Brackets are the unofficial standard for English threaded cartridge bottom brackets. Quality, value, and durability come together to keep you cranking for many, many miles. Fits JIS Square Taper Cranksets Hollow spindle Crankarm fixing bolts not included