Joined: Sep 2005
Posts: 3,002
Likes: 303
From: Hervey Bay, Qld, Australia.
Bikes: Colnago (82, 85, 89, 90, 91, 96, 03), 85 Cinelli, 90 Rossin, 83 Alan, 82 Bianchi, 78 Fountain, 2 x Pinarello, Malvern Star (37), Hillman (70's), 80's Beretto Lo-Pro Track, 80's Kenevans Lo-Pro, Columbus Max (95), DeGrandi (80's) Track.
Looking at the photo you took of your bike (side view) it appeared that the down tube was tapered from a smaller diameter at the top and a larger diameter at the bottom. I just assumed that it had grooves or crimps pressed into the tube as my bike has. Other Conic SLX's i've seen have a similar tube treatment as mine. Perhaps yours is more 'special' than initially was thought. Perhaps someone else could help out with a more definative assessment of your frame.
As I stated, my bikes downtube is tapered. It is narrower at the top and gets wider at the bottom bracket. The 'crimping' seems to start just below the lever bosses and ends about 3 inches from the bottom bracket. The crimping starts at nothing and gets deeper as the tube increases in diameter.