RE:VINTAGE LIGHTWEIGHTS: gios aerodynamic posted by T-Mar on 2/28/2004 at 9:36:07 PM
Columbus Air was the Italian manufacturer's initial attempt at an aerodynamic tubeset. It dates from the early 1980's. The intial version used a teardrop shaped down tube, seat tube and seat stays in conjunction with an oval top tube and chain stays, and a round head tube. Later versions had teardrop shaped chain stays.
The tubeset was designed primarily for time trials and aerodymanic efficiency and therefore it is not practical to compare it directly to other round, Columbus tubesets. However, based on tube thickness, the seat stays were equivalent to KL and the chainstays, seat tube and top tube were equivalent to SL, while the down tube was equivalent to SP. Due to the teardrop shapes the resulting frames weighed more than SL, but had less strength. The rear triangles in particular had a reputation for being whippy, due to the thin seat stays. However, this was considered acceptable given the intended TT use and aerodynamic advantages.
Of particular note, the seat tube came in two versions. One with a standard round top end, to accept a normal seat post and another which carried the teardrop section right to the top, requiring a teardrop section seatpost. If you have the latter, you may have some difficulty finding a seatpost, unless it is being provided with the frame.
Regarding componentry, most frames built with this tubing were outfitted with Shimano Dura Ace AX, or less likely, 600AX. Campagnolo did not have an aero group at the time and the Italian farme builders did not want to miss out on the aero bandwagon, in the event it turned out to be the latest craze. The AX components come up fairly regularly on Ebay and are not as expensive as buying Campagnolo NR or SR. I had a similar, aerodynamic time trial bicycle in the early eighties, with full Dura Ace AX, though it was not a Gios.
You might want to browse that site for more info... google motobecane+teardrop for more hits...
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