THM Tibia 78g road bike stem

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.

The latest Fibula carbon fiber rim brake caliper also showed up at Eurobike, but in prototype form. Now, they’re in formal carbon fiber construction, and to drop weight further, they replaced the steel return spring on the back of the arms with carbon fiber.

The brakes were reworked to provide better tire clearance, easily passing a fully inflated 28mm tire between the brake pads if you need to remove the wheel. The red cam is adjustable to work with rims from 19mm to 30mm wide without changing cable length or clamp point. Claimed weight is just 120g for the set, with a retail price around $1,000.

THM.bike 

16 COMMENTS

    • We can agree with the 5 first words… Yes light. But plenty stiff clearly not, you could mention “stiff enought for me”, but all test show them as very flexy. (Fairwheels stem test is the first that comes in my mind)

  1. The small diameter transverse rods at the front, with the threaded studs that the face plate attaches to; those give me the heebie jeebies. I hope their FEA guy is good.

    And the steerer tube clamping system, with the aluminum posts, surrounded by carbon fiber with stainless or titanium fasters; all that’s needed now are a couple tablespoons of sweat for a nice science class corrosion experiment.

    With most race bikes coming in under the UCI limit with relative ease with off the shelf parts….

    Neat stem though.

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