Steel frame differences

[RichMc]

What are the differences between the Serotta steel frames. OK, the Coeur d'Acier has a carbon seat stay but, apart from that, the CSi & the Colorado III frame feature descriptions are identical. All use the Niobium triple butted steel, etc. So what are the other differences that set these three frames apart from each other, besides price? Thanks.

[Ozz]

Colorado III is TIG welded

CSI is lugged or filet brazed. If you get the 1.125" head tube, these joints are filet brazed.

The Couer d'Acier is a CIII with the carbon seat stays.

[bcm119]

They all use identical tubing (in varying diameters of course), but are constructed differently: the CIII and CDA are tig-welded and the CSI uses lugs (also available as filet brazed). The lugged construction is mostly an aesthetic issue- the only functional advantage perhaps being ease of repair; the higher cost is due to increased labor/lug cost. The CDA is identical to the CIII but uses a carbon wishbone seatstay with aluminum, non-pivoting bosses at the drop outs. The tig-welded frames can be custom built using smaller increments of angles; the CSI's lugged construction allows fewer frame angle options because of lug availability.
All of these frames can be built to perform the way you'd like them to. In general, the CDA has a different feel because of the carbon stay, but some would disagree with me there. I test rode one and felt a pronounced buttery-smooth feel, but I didn't like the disconnected feel on climbs/sprints. This is just one opinion though. Hope this helps-

[Climb01742]

i have both a CIII and a fillet-brazed CSi. both are wonderful, but the CSi is like old-fashioned french cooking--extra buttery. it has a distinctly different ride. even though the tubes may be of the same kind of steel, kelly and company can do some cool tweaking to create distinctive rides.