S22

S22AR/CR/DR — compact 2-piston caliper for the rear axle of small cars (A class). OVERVIEW S22 is a mass-produced compact 2-piston caliper of our own design. The body is forged from aluminium alloy: forging delivers high rigidity, tensile strength, toughness and material density. Compared with cast aluminium calipers, body rigidity is about 50% higher, which reduces the risk of caliper failure in service. The built-in double oil seal (instead of ordinary external dust boots) makes the brake feel and reaction more precise. After anodizing and vacuum coating (CVD) the colour is locked in: the coating does not crack or peel and gives the caliper a metallic sheen and vivid colour. HIGHLIGHTS • One of our mass-produced compact 2-piston calipers. • Provides a more linear pedal feel. • After rigorous multi-stage testing, performance is about 35% above the stock caliper. • With high-performance pads it confidently handles intense driving — from mountain roads to daily use. CALIPER SPECIFICATIONS • Weight: 1624 g/pc • Piston area: 22.42 cm² • Piston diameter: 38 mm × 2 • Brake disc diameter: Ø332 mm–Ø300 mm • Brake disc thickness: max 26 mm / min 10 mm • Caliper dimensions: AR — 203.3 × 137.1 × 68.4 mm; CR — 203.3 × 129.1 × 68.4 mm; DR — 203.3 × 129.1 × 68.4 mm • Oil inlet thread: M10×1 • Mounting hole centre distance: 141 mm • Mounting hole offset: 29 mm • Mounting hole diameter: 10.25 mm • Distance from mounting plane to the top of the disc: 20.43 mm BRAKE DISC • Friction surface width: 54.5 mm • Ventilation: Ø332 mm × 10/26 — 72 curved ducts, 7 slots, PCD 183/210 mm; Ø300 mm × 10 — 72 curved ducts, 7 slots, PCD 183 mm • Heat treatment: 580 °C heating / 120 °C cooling, cycled for 72 h • Mounting hole diameter: Ø8.1 mm • Centring ring: Ø190 mm (for Ø332 × 26 disc), petal step 2.5 mm; Ø170 mm (for Ø332 × 23 disc), petal step 2.0 mm • Surface treatment: iron phosphating, ground friction surface • Disc standard: GG20HC BRAKE PADS • Model: S22 • Thickness: 13.2 mm • Friction surface width: 44.7 mm • Friction block area: 30.4 cm² × 2 pads per caliper • Compound: F500 (standard) / F600 (street, optional) / S750 (street & track, optional) / R900 (track, optional) / S800 (for carbon-ceramic discs, optional) QUALITY CONTROL • Forged body tensile strength: Qb ≥ 320 MPa • Body hardness: HV ≥ 400 • Low-pressure seal test: 0.4 MPa air, hold 5 s, pressure drop ≤ 100 Pa • High-pressure seal test: 12 MPa air, hold 5 s, pressure drop ≤ 0.2 MPa • Appearance: anodized surface free of damage, uniform colour and gloss • Ultra-high pressure test: sampled calipers withstand 30 MPa oil pressure without failure • Other characteristics per QC/T592.