I noticed some bikes have them and some do not. What is this cable for?
The first picture of a 800 Drifter, I see a speedo cable and what I am guessing is wiring for the lights on the front forks, the second picture is a 1500 and what I think you are looking at might be the brake hose for the front brake.
Is this the difference in the R and J models. Digital tach vs mechanical. I've seen it on both 800 and 1500.
The first pic you show is an 800 Drifter with speedometer cable circled. The second pic is a 1500 Drifter "R" model, no speedometer cable (electronic speedometer). The 1500 "J" models have the cable (mechanical speedometer).