Rotor has launched their new SL mountain bike stem weighing in at just 83g for the 90mm size.  There’s also a 105 (88g) and 120 (93g) available.  It has a +/-6° rise, and fits 25.4 diameter handlebars.  Despite the lightweight, Rotor claims the stem is exceptionally stiff and strong, and from the looks of it, the clamp area that secures the handlebar actually looks like it covers more area than lightweight offerings from Ritchey and Easton.  The secret to achieving the desired strength is the bolts.
The stems use their Evo DTT (Double Thread Technology) bolts to accomplish high clamping power in such a lightweight package.  Basically, DTT is a special bolt thread pattern the keeps it tight.  The bolts are steel, for strength, with no weight penalty over the alloy ones used in their ’08 components.
These same bolts will replace the alloy ones in their new Agilis Evo cranks for ’09.
