[RogerR]

i would strongly recomend using the pre-drilled bolt hole circle(s) to transmit the torque. these bolts will be able to handle farily high torque, leaving the shaft to deal with the relatively tame shear loading. also, i'd check the loading specs on the bearing, but you're probably not gonna overload them.

aditionally, i'd also double check your torque calculations; if i recall, the tiagene motor has a torque of 34 Nm, or roughly 25 ft*lbs; with a 60:9 reduction, you'll be stalling (or close to stalling, depending on the rotation direction) the motor. a stalled motor is never a happy motor. a good rule of thumb is to not load the motor more than 25% of its stall torque. also, is 190 ft*lbs correct? i have no idea what your mechanism is, but to generate a 190 ft*lb torque at the end of an 80" lever arm, you'd need almost 30 lbs of load, seems pretty hefty.