We first saw the new THM Tibia stem at Eurobike, but since then the design has been refined to get rid of the shark nose faceplate. It does, however, keep the 78g claimed weight in 100mm length, which starts shipping in July. They’ll have 80, 110 and 120 lengths shipping in September. What’s equally interesting as its weight is its construction method…
There’s more than just carbon fiber and insanely light weight justifying its $650 retail price.
The faceplate bolts are attached to (as in, part of) a pivot, which lets them move rather than bend, so they’re able to be thinner. The front part that looks like the bolt head is actually a nut that threads onto the bolts. The weak part of a carbon stem is often the alloy inserts bonded or glued into the stem, and there’s none of that here.
The walls use a structural foam on the inside that adds rigidity without adding the same weight that additional layers of carbon would add. That’s what gives it the (claimed) highest stiffness to weight ratio of any stem in the world.
The faceplate is also a carbon wrapped structure, but a different material that they won’t disclose. There’s more tech info on the materials in our Eurobike coverage here.
