The Impact headset has many of the features that have become headset buzz words, "headlock", and "oversized bottom bearings". Let's start at the top. The headset is designed by Joe Murray and made in Taiwan by YST. This doesn't use a headlock and head key washer in the common sense. It has a single piece made of machined aluminum and steel that is the equivalent of the head lock nut, head key washer, and upper cup race. This piece features a clamp to lock this upper headset piece down on the fork steer tube, in fact it's done like the Mavic 315 headset. There is a cut at the top of it with a 5mm allen bolt that passes horizontally to draw up and cinch the head lock nut firmly in place. It has a clever thread-in plastic stem seal on the top of the lock nut device. The steel upper cup race is ground and then painted black. Because of the complexity of this upper piece, the only practical way to create the cup that covers the bearing is to make it as a separate piece and fasten it to this machined top piece. This shroud piece is made of plastic and is held in place by a cone race that is pressed onto the head lock device. The bearing retainer in the assembly uses twenty-two 5/32" bearings. The fork crown race seems to be stamped steel which has a ground bearing surface that is painted Black. The lower bearing cup is steel, which is polished, then painted Black. The bearing retainer in the lower assembly uses fifteen 1/4" bearings. The oversized lower bearings can accommodate more abuse and should produce longer wear. The lower assembly is surrounded by a molded, yet removable rubber "bearing boot". In the early days of mountain biking, dirt contamination in the headset was common. Adequate seals didn't exist yet. Pioneer MTB riders would cut a 1 inch section out of an old tube and use it to vertically enclose the headset assemblies as a seal to keep dirt out. The Impact's rubber boot is designed to do this more efficiently. The 1" version weighs 148.5 grams and has a stack height of 39 mm. Black only. Joe Murray now works for Titec replacing Mr.Bontrager and the Impact headset is no longer imported by Kona. They now sell the Control Center headset. We sold both sizes of the Impact for $24.99
