Mountain Bike Carbon Fiber Fork (Thru-axle). Fork Size: 27.5 inch and 29 inch Fork Upper Tube: Cone Type Upper tube diameter:28.6mm Bottom tube diameter 39.8mm Upper tube length 249mm Fork Stanchion: Diamter 32mm Aluminum alloy Fork Travel: 100mm Fork Opening Space: 100mm Fork Weight: 1480g(27.5) Applicable For: Hydraulic Disc Brake Features: Oil and gas fork, shoulder controlled oil pressure lock/single air chamber. 28.639.8 Tapered Tube. Front fork bottom rebound speed and slow damping adjustment A/V Air Valve.