Prdocut Description: A bike headset is a component of a bicycle that connects the fork to the frame and allows for steering of the front wheel. It consists of several bearings and races that allow the fork to rotate smoothly in the frame's head tube. The headset also helps to absorb shocks and vibrations from the road, improving the bike's overall comfort and stability. The threadless headsets have a smooth steerer tube and clamp onto the fork using a system of spacers and a compression cap. Our headset includes all the necessary parts including star nut, compression ring and bolt, cups, sealed bearings and crown race, top cap etc. Measure the head tube and fork tube dimensions to ensure the compatibility Crown Race is Included Juscycling offers a comprehensive product line of threadless headsets. Check the comparison chart below for compatibility of other headset types if this one doesn't meet your bike's specification. 44-44MM for 1 1/8" Straight 44-44MM for 1 1/2“ Tapered 44-52MM for for 1 1/8" Straight and 1 1/2" Tapered 44-55MM for for 1 1/8" Straight and 1 1/2" Tapered 41.8-52MM for for 1 1/8" Straight and 1 1/2" Tapered Add to Cart Add to Cart Add to Cart Add to Cart Add to Cart Customer Reviews 4.4 out of 5 stars 9 4.9 out of 5 stars 6 5.0 out of 5 stars 3 5.0 out of 5 stars 4 3.6 out of 5 stars 5 Price $16.98$16.98 $19.98$19.98 $24.98$24.98 $19.98$19.98 $19.98$19.98 Type Zero Stack (Semi-integrated) Zero Stack + External Cup Zero Stack + Integrated Zero Stack (Semi-integrated) Integrated Upper Head Tube ID (mm) 44 44 44 44 41.8 Lower Head Tube ID (mm) 44 44 52 55 52 Crown Race ID(mm) 30 39.9 30 or 39.9 30 or 39.9 30 or 39.9 Fork Seat OD(mm) 30.1 40 30.1 or 40 30.1 or 40 30.1 or 40 34-34MM for 1 1/8“ Straight 44-56MM for for 1 1/8" Straight and 1 1/2" Tapered Add to Cart Add to Cart Customer Reviews 5.0 out of 5 stars 6 4.8 out of 5 stars 4 Price $16.98$16.98 $19.98$19.98 Type External Cup Zero Stack (Semi-integrated) Upper Head Tube ID (mm) 34 44 Lower Head Tube ID (mm) 34 56 Crown Race ID(mm) 30 30 or 39.9 Fork Seat OD(mm) 30.1 30.1 or 40