The bottom bracket axle is permanently mounted to the right hand crank and has splines for the left hand crank.

而中轴本身是和(安装大飞的)曲柄连为一体的。

youdao

Also, in the query [dura ace track bb axle njs] the “bb” is probably referring to a bottom bracket while in the query [software update on bb color id] the “bb” probably means blackberry.

而且，在查询dura ace track bb axle njs时，"bb"指的应该是底架（bottom bracket），而在查询software update on bb color id时，这里的bb说的应该是黑莓手机（blackberry）。

youdao