The Stronglight 650 is a "dual adjustable cup with fixed length spindle" B/B that permits the spindle, exposed on the crank side, to be adjusted very precisely, allowing crankset/chainline adjustments to be perfect.
The 650 uses machined bearing cups made of aluminum rod. Each cup has four small, round dimples in the side for a peg spanner to make small, fine adjustments. The interior of the hole where the spindle exits the bearing cup has been milled with a groove for an O-ring to seal the system, but the needed O-ring has been omitted. A machined aluminum lockring on the left bearing cup holds the system firmly and fixed in the B/B shell. Into the bearing cups, a precision sealed bearing cartridge fits from the inner side. The French made SKF 61903 RS1 is used.
The 650 has a Titanium spindle machined from Ti 6Al-4V rod, that the bearings are machine pressed snugly onto. At the time the bearings are pressed onto the spindle a tight fitting water sleeve is inserted between them. Because the bearings aren't pressed onto the spindle easily, field replacement isn't an option. It will take a partially closed bench vise to support the inner side of the bearing and the firm rap of a hammer, on the top of the spindle, to free it. The spindle is drilled through to reduce weight with the interior ends tapped for the steel crank bolts and washers included with the 650. There is an opaque, clear-colored plastic moisture sleeve to keep dirt and moisture from penetrating the B/B assembly.
The Stronglight 650 is available in English thread only, with a 114mm, 118mm, 124mm or 127mm spindle. The weight of the 650 with a 124mm spindle (with crank bolts and sleeve, which weigh 31 grams) is 217 grams. Made in France, the cups are Silver, lockrings are Black.
Spindle Length-14-18-24-27 $Price in Catalog