ZTTO Internal Cable Routing​ Bicycle Headset Threadless IS52 ZS56 Tapered 1.5" 28.6mm 52mm 56mm Bike Frame Hidden Line

ZTTO Bicycle Internal Cable Routing​ Headset Spec: Material: CNC-machined 6061 aluminum with chromoly steel seal bearings. Cable hole: 4mm x2 , 5mm x2 Compatible with 1 1/8" and 1 1/2" fork Weight: N5252ST about 110g, N5656ST about 140g Bearings angle: 45°/45° Bearings Size: 52x40x7 Cable hole angle: about 30° (soft rubber ​​Compression Ring for IS52: 6.5/7.5/8.5mm SHIS(Standard Headset Information System) N5252ST= IS52/28.6, IS52/40 (with 30 adapter ) N5256ST=IS52/28.6,ZS56/40(with 30 adapter ) N5656ST=ZS56/28.6,ZS56/40(with 30 adapter ) ​​3 Compression Ring Thicknesses​​ (6.5mm / 7.5mm / 8.5mm) For IS52 for perfect frame-crown gap tolerance. ​​Come with 0.3mm and 0.5mm Shims​​ to fine-tune stack height ±0.7mm. Critical: Measure your frame’s depth before choosing ring thickness (see diagram in images). IF YOUR FRAME IS ZS56, then Ignore this description, ZS56 just works with bearing cups, no need to choose compression Ring. Positioning Pin ​​Optimized Angled Ports​​ about 30° (soft rubber) slanted entry ports minimize cable drag for responsive shifting.