The bicycle drive unit 1, wherein the detent plate 16 is machined into the rotary plate 5 with {TAIL ~ a plurality} of {HEAD ~ detent grooves} 16 a included therein, 
The bicycle drive unit 1 , wherein the detent plate 16 is machined into the rotary plate 5 with { TAIL ~ a plurality } of { HEAD ~ detent grooves } 16 a included therein ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH