MK0 Upper Headset Assembly

What Our Gearhead® Experts Are Saying:

"I spec'd the MK0 Upper Headset Assembly on a dedicated race build where front-end geometry was dialed to the millimeter, and any excess stack would have thrown off the whole setup. The 4mm height landed exactly where the math called for, the Enduro bearings rolled in smoothly, and the triple seal setup means I'm not pulling the headset apart every few months to chase out moisture."

Front-end geometry is a conversation that happens in fractions of a millimeter on a performance build, and the MK0 Upper Headset Assembly from Wolf Tooth Components is engineered for riders who treat stack height as a hard constraint rather than an approximation. At 4mm, it represents the shortest possible stack Wolf Tooth can achieve while maintaining the bearing support, sealing integrity, and strength required for long-term reliability under load.

Each upper assembly is machined from aircraft-grade 6061 aluminum at Wolf Tooth's Minneapolis facility, spending four times as long in the CNC lathe as the standard Premium Headset design. The result is a 44% reduction in aluminum weight, with visible machine paths that intentionally reference the broader MK0 aesthetic. Enduro stainless steel sealed bearings are included and set to a 36 x 45 degree bevel angle, providing smooth, consistent steering feel across road, gravel, and mountain applications. Sealing runs three layers deep, with an o-ring at the steerer tube interface and a custom-molded upper lip seal over the bearing race, blocking water intrusion at both contact points. A matching MK0 stem cap and custom hollow bolt are included to complete the upper assembly.