While a sometimes forgotten notion, lightweight means little without proper strength. A very shallow search on the internet can reveal all sorts of crazy lightweight parts and bike builds. But are they even rideable? Or do they ride well?
German carbon manufacturer THM has put a few unique spins on the traditional stem to come up with what it claims is the “world’s best stiffness-to-weight ratio” stem, the 78-gram (10cm length) Tibia.
The face plate is an all carbon piece Russell Eich / Immediate Media
Nuts, not bolts
To achieve the feathery weight, yet retain the stiffness THM claims, the company flipped the stem’s face plate mounting system around.
That means instead of threading bolts through the face plate into the stem body, the stem bolts protrude from the stem itself.
The bolts are independently adjustable to minimize stress Russell Eich / Immediate Media
The bolts are independently adjustable so as the face plate and bars are snugged up, the bolt is free to shift and orient itself in a place of least stress.
The T15 Torx stem nuts have a tapered end for simplified centering in the face plate holes as well.
Like the stem/bar interface, the steerer clamp is also designed to minimize stress. The bolts are threaded through a shaft that is allowed to rotate to compensate for the tightening deformation.
The steerer clamp is designed to relieve stress as well Russell Eich / Immediate Media
Weight and availability
The 100mm Tibia stem they had available has a claimed weight of 78g and should be available in July.
Additional lengths of 80mm, 110mm, and 120mm did not have published weights and are due in September.