Bottom Bracket - 04

BOTTOM BRACKET:
Stronglight 650 Titane - traditional non-cartridge adjustable type bottom bracket for 68 mm shell - 6Al-4V titanium alloy rifled spindle with oversized mid section - square taper - 118.5 mm width with 2 mm drive side asymmetrical offset - SKF 61903 RS1 annular sealed bearings - 35 mm x 1 mm (25.4 TPI) French threaded aluminum alloy cups (non-drive side adjustable cup - right threading / drive side fixed cup - also right threading) - aluminum alloy lock ring - "accordion" style plastic dust sleeve - model 650 Titane : Stronglight Competition crank bolts and washers - aluminum alloy - M8 x 1.00 x 20 mm bolts with 16 mm head / M8 flat washers - model 59D (bolts) / 60D (washers) ... [Unlike its Campagnolo Super Record counterpart which was notably flexible and subject to occasional and often most inopportune failure (...remember Laurent Fignon?), characteristics long attributed to the assertion that its slender spindle had been crafted from relatively low strength Commercially Pure (CP) titanium, the Stronglight 650 Titane unit utilized not only a hollowed spindle having an oversized mid section but one which was also certifiably constituted of an alloyed version of 6/4 titanium (...6% aluminum and 4% vanadium with the remaining 90% being titanium - roughly three times stronger than pure titanium), which enabled it to much better withstand the rigors of competitive use. Arguably the best titanium bottom bracket in its day, the Stronglight 650 Titane made its public debut at various cycling industry trade shows held during the waning months of 1975 and was subsequently an integral part of the Peugeot PY-10 that Bernard Thevenet rode to victory in 1977 for his second Tour de France title. Those Peugeot PY-10 CP models offered to the public that very same year came equipped with a robust steel spindled Stronglight model 651 bottom bracket as the base model standard with the 650 Titane seen here being a racing oriented optional upgrade which was made available at extra cost. Either of those assemblies would have been supplied with Black oxide finished steel crank bolts and flat washers (...although titanium versions would eventually be supplied with the Stronglight 650 after the year 1984). However, those have been replaced in this instance with Stronglight Competition aluminum alloy fittings (...which had just been introduced to market late in the preceding calendar year) consistent with that equipment used on select Peugeot-Esso-Michelin team bikes during the 1977 racing season (...although on genuine team bikes, these particular alloy bits were often painted matte Black subsequent to installation so as to simulate the oxide finish of their steel counterparts - a clever ploy intended to disguise a weight saving secret.]