For those of you still using mountain bike handlebars with a slender 25.4mm clamp diameter, Rotor has updated and upgraded its superlight XC 25.4 stem.
While most bars and stems go with the oversized 31.8 clamps, Rotor is aiming at fans of Euro-style, ultralight bars and stems.
The new SL2 has been updated with a conical stem body, which the company says offers a massive improvement in rigidity with just a minimal increase in weight. It also features a completely redesigned stress-reducing steerer tube clamp with one oversized dual thread pitch (DTT) bolt and insert, a technology pioneered on Rotor’s 3D crank.
The new single DTT bolt has a replaceable threaded aluminium insert on one side that functions as an intentional failure point to prevent damage to the stem in case of overtightening or a crash.
Rotor says the single DTT bolt spreads tightening forces more evenly than two bolts can, while also reducing the need for complex reinforcement structures in the clamp. The company says the stem exceeds the fatigue requirements of the most demanding certification in the market and gained its EN 14766 certification at the EFBe laboratory, in Germany.
The new SL2 stem weighs 91 grams for a 90mm version, and 102 grams in the 120mm length. A 105mm extension is also available, and all the sizes feature 6 degrees of rise. Expect to pay about $200 for the new stem, and look for it to be available next week.