The normal fitting of the pannier frame is only at three points. The bottom rail is horizontal and fits from the footrest bolt, horizontally and turns up and curves inward to bolt under the mudguard using the rear number plate bolt. It also has the two lower pannier bolt holes in it. That should be possible on your Triumph, but I don't know whether it would interfere with rear wheel removal. The vertical rail normally rises vertically from the horizontal rail just behind the front edge of the pannier to the top rear suspension bolt with swinging arm, but in your case it might be possible to arrange a clamp onto the frame. The third rail runs diagonally downward from its welded junction with the vertical rail, curving at the lower end like a cut off letter "J" to pass over the rearward hole in the pannier. All rails are welded together. I manufactured my own in a couple of hours from flat mild steel bar, but of course I had welding gear to weld the joints and bend the bar.
I could let you have asketch of my frames with dimensions for you to modify if it helps.
If you do not manage to fit them to your bike and they are in decent condition, I would be delighted to buy the from you!
