1988 Bridgestone RADAC Carbon
This pretty rare Bridgestone RADAC Carbon has a 55cm seat tube measured c to t with a 54cm top tube. It’s outfitted with complete Dura Ace 7400, Eng. BB and HS, 170mm cranks, 52x42, 13-21 Dura Ace freewheel, Cinelli 64-38 bars and a 85mm 1A stem. The rims are Mavic G40 clinchers, 36 spokes. Selle Italia Turbo saddle.
If you’re bound for L’Eroica, the only changes you might consider (depending upon how “heroic” you want to be) would be to fit a wider range freewheel, toe clip style pedals and new bar tape. The hard-to-find original brake hoods are ratty but useable. Yes, the Eroica rules dictate "pre-'88" but no one cares or will know what this thing is anyway
Only about 20 Bridgestone RADAC Carbons were imported to the U.S. The much more common RADAC was all aluminum in construction and more affordable. The Carbon model up for sale here was made only one year and in extremely small numbers due to the high price and difficulty of manufacturing. The tubes are super thin walled aluminum with a carbon wrap. After much research in the mid-1980’s, the Bridgestone engineers realized that galvanic corrosion takes place between aluminum and carbon unless other measures are taken. By gluing a carbon wrapped aluminum tube to aluminum lugs they could avoid most of the corrosion issues. Galvanic corrosion would later plague carbon bicycle construction worldwide for the next 20 years.
RADAC was an acronym for Research and Development Adhesive Cement. In the early 1980’s Vitus, Cannondale, Klein and others had great success with their aluminum racing frames. The world market scrambled to respond to this clever technological advancement. Bridgestone’s engineers zeroed in on the major weakness of Vitus (the most successful frame in professional road racing at the time), the tendency of the glued joints to fail. To take on this popular tidal wave of aluminum frames construction, Bridgestone’s solution would hinge on a better way to join the tubes and lugs. But it wasn’t just the glue, even though the smart ass punks (I can say this because I was one of them) in the U.S. office coined an inside joke. Said in a whisper, “It’s the glue”.
RADAC aluminum lugs had a small pattern of bumps on the surfaces, so the layer of adhesive would remain equally distributed and therefore provide a better bond when mated to the tube. The presses used to assemble the frames had to work in unison, so the main triangle went together simultaneously, not just one tube at a time. Even with better engineering and a competitively priced product, the RADAC was never successful on the sales room floor, as it was viewed as an expensive “me too” product. As good as they were, it was hard to discern clever engineering and quality construction just by looking at one.