They include custom made stainless steel bearings (which are replaceable). Sealing is achieved through an adjustable taper ring cover and integrated rubber seal. These are by far the most popular headsets here at Biketart.
Hope Standard headset
Hope Standard Fixed Disc Rotor 6 Bolt 120 160 180 183 185 200 203 205 220 225mm
Hope Standard 6-Bolt Disc Bolt Rotor
Original Hope (UK) Headset Head Bolt - Silver - c/w Hope Packaging
Original Hope (UK) Headset Doctor Spacer Set - Silver - c/w Hope Packaging
Sealed Headset Bearings for Road and For Mountain Bike Maintenance Compatible with Standard Headset Cup Sizes (41.8MM)
