The /5 bikes are model years 1970 to 1973. They started with what became known as the SWB, Short Wheel Base, models and later the wheel base was lengthened by the extension of several parts of the frame. To begin with the swing arm is longer in a LWB bike, Long Wheel Base. This longer part can sometimes be recognized by welds in the drive shaft tube of the swing arm, but that is not a diffinative touch because the swing arm may be a longer one with out the welds. Picture stolen from Duane Ausherman. The sub frame is longer and the seat is longer on a LWB bike. To make this more confusing there is no cut off or model change date. For a while they made both LWB and SWB bikes. And in the later 70's and 80's it was popular to make a LWB /6 or /7 into a SWB bike by swapping some parts around. You just have to learn how to spot them How all this effects the luggage is interesting. The bag frames attach to several places. On a LWB bike the frames are different. The bags are the same but not the frames.