Mavic's specially designed bottom bracket requires personal courage, real expertise, or professional installation, but will last you a life time. This bottom bracket is another variation of the floating style bottom bracket unit, this one is made to achieve very fine and minute adjustments. Installation requires that your bottom bracket shell is re-faced to make the shell faces perfectly parallel and chamfer the inner lip of the B/B shell slightly.
The re-facing to make this B/B fit will require the elimination of the outer few threads inside the B/B shell. This is done to accept Mavic's special mounting rings that use a threaded compression fit. As the threaded aluminum lockrings are tightened, they compress 45 degree chamfered sides into the B/B fixing the bottom bracket in place. The body of the unit is an aluminum tube into which sealed bearing cartridges are fit and then seated with an internal aluminum lockring (similar to their hub design).
The spindle is made of hollow machined steel and available in seven lengths. Also included are a pair of steel crank bolts and washers, (33 grams). With the spindle in place the entire unit is held by beefy aluminum locking compression rings at each end. You can adjust your chain line easily due to the bottom bracket's floating design. This B/B has the bearings positioned at the extreme ends of the bottom bracket shell, which increases support, and lengthens the life of the bottom bracket.
Available in spindle lengths of 114mm, 116mm, 119mm, 123mm for Road bike use, and 124mm, 128mm, or 134mm for mountain riders. The 114mm Road model weighs 317 grams, including the 33 grams crank bolt/washers. In the 134mm spindle length, it weighs 365 grams, (including the crank bolts and washers which weigh 33 grams), it isn't the lightest, but is one of the smoothest bottom brackets available.
This bottom bracket is your only salvation if you've somehow seriously cross threaded or stripped the threads of your B/B shell, because it can be installed in a shell lacking inner threads.