Originally Posted by
Deerman
I may have figured out how custom-built Bianchi road bike serial numbers work (at least in some instances).
There is a long-running debate on the forum about SBX frames with late 80's stickers. SBX is from 93/94 so this causes consternation...
The serial number is the key (I think anyway): the format "B" XXX-XXX is reserved for custom builds. "B" means Bianchi - made in Italy at the Bianchi factory. The rest of the number is simply the frame number increasing incrementally - starting at "000-000" and going to "999-999".
My SBX has late 80's stickers and the serial number is B 008992. Other posters with similar "weird" SBX frames have B 008919 and B 008905. These frames were probably made close in time together but they are each custom - geometry, cable routings etc. These bikes are all SBX - so probably made in 1993/4. Custom frames are notable for design differences from the production bikes (decals, simpler brake mount, no pantographs etc.). It seems the Bianchi design philosophy for "custom racing frames" is to keep it simple - no fancy stuff, just function. A bit like a racing car perhaps?
I never trust decals on a Bianchi, as it is arguably the most popular brand to "flip". Consequently, to maximize the return on investment, there are a lot of replacement decal sets and even repaints. There are a lot of "flippers" who choose decal sets based on their personal preference or cost and not necessarily what is era correct. They tend to prey on the "newbies" who want a celeste Bianchi at any cost.
Bianchi didn't introduce SBX until after they introduced their Superset II frame configuration in 1991. Superset II frames are easily identified by their down tube, which is slightly oversized and takes on an oval shape at the bottom bracket. To ensure it's SBX you also have to look inside the BB shell for the five helical ridges at the ends of the doen tube, seat tube and chain stays. To the best of my knowledge, the SBX frames were built to standardized geometry.
Rather than "keep it simple", my take on the cosmetic evolution of the Bianchi racing frames has been "keep it inexpensive". In the early to mid-1980s there was lots of embossing, In the late 1980s the embossing started to be replaced with decals. In the 1990s even that disappeared. This was probably to offset the technological frame developments, first with Superset, then with Superset II. Bianchi was big into the development of eponymous tubesets with Columbus, such as Bianchi Special, Formula One , Formula Two and SBX. The frames were advancing technologically but the cosmetics were getting more plain.