The single spine frame came with the original 1978 CX and the same basic design was used on all of the CX frames to 1981. Things like fuel tank mounting points, for example, differ between some models. In 1982 the Custom and Shadow still used this frame, but the 500E Sports, Turbos, all GL500 and 650 variants and the CX650E used versions of the triple backbone frame. The CX650 Custom used a single spine frame that was significantly different to the original CX frame, and that is not covered here.
This frame is easier to get the “empty triangle” under the seat with – it lacks the two vertical spars of the triple backbone frame, instead continuing the single spine down the center:
This frame came from the factory with dual rear shocks; you can see the top shock mounting point in the upper part of the photo below. The other mounting points are on the final drive unit and the left hand side of the swingarm.
The rear of the frame has a bump stop across the frame – which also gives the frame structural rigidity. If your suspension fails (or you have messed with it) the bar across here will stop the tyre from slamming into your seat/backside at speed.
Front engine hanger mounts:
To see what the triple backbone frame looks like, see here.