Where it’s needed, BTR frames have a head tube gusset. Initially that was a flat X-shaped piece on either side of the frame at the head tube. Nowadays we use an ovalised tube instead. Both of these solutions do their job very well; they increase longitudinal stiffness of the head tube by around 20%, and decrease the peak stress at the head tube by around 15%. They are far more effective than reinforcements which lie flat against the down tube or top tube, as used by many other manufacturers.