A bicycle bottom bracket assembly has a crank axle, a pair of bearing units and a pair of retaining clips. The bearing units are configured to be mounted in a tubular hanger part or bottom bracket tube of a bicycle frame. The crank axle has a central portion, a first axial end portion with a first recess disposed on a first side of the central portion and a second axial end portion with a second recess disposed on a second side of the central portion. One of bearing units is disposed on the first axial end portion of the crank axle at a location axially inward of the first recess, while the other bearing unit is disposed on the second axial end portion of the crank axle at a location axially inward of the second recess. One of retaining clips is disposed in the first recess and is configured to retain the one of the bearing units on the first axial end portion of the crank axle. The other retaining clip is disposed in the second recess and is configured to retain the other bearing unit on the second axial end portion of the crank axle.