Thomson X4 31.8mm Bicycle Stem - Lightweight Aluminum MTB & Road Bike Handlebar Stem for Cycling Enthusiasts - Perfect for Trail Riding, Commuting & Performance Biking

I am using the X4 on a road bike although it's marketed as a mountain bike item. As such, there is about a 50 gram weight penalty over say a Ritchey or a 3T road stem. Thomson's X2, the road-specific stem, competes in weight but I can't recommend it due to flex and the clamp having only two bolts. Headscratcher there...the X2 is Thomson's only mediocre product. The X4 benefit however is vastly superior stiffness - noticeable immediately and, the large clamp in my logic will be inherently kinder to finicky carbon handlebars. A stem review by Fairwheel Bikes a few years ago actually measured "compliance" i.e., flex under a twist load as in riding. Out of a bunch of carbon and alloy stems, the Thomson X4 took second overall being bested only slightly the Shimano Pro Vibe sprint version seen on Cavendish's rig and Theo Bos's Keirin bikes. The Thomsons are the best made stems and seat posts available in my opinion. The machining is exquisite and the overall quality is without equal. I can also validate Thomson's claim as to their seat post clamp being superior. That thing is the best way to NOT crack your $160 carbon post as it holds securely at 2.8 Nm. (BTW, get yourself a REAL torque wrench - not the "clicker." I learned that after cracking two of them...ouch.)