A range of anti-knockback springs are available for AP Racing calipers. The spring is located behind the piston in the caliper bore and is designed to counteract pad knock off. The springs are available in four loads indicated in lbs/f (force) with 2 sizes dependent upon piston diameter.
Piston sizes up to Ø34mm
| Spring Load | Part number | Free Length & Wire Ø (mm) |
| 4 lbs | CP2632-113 | 38.43 & 0.91 |
| 7 lbs | CP4100-121 | 39.88 & 1.02 |
| 9 lbs | CP3432-134 | 49.02 & 1.02 |
| 12 lbs | CP2632-129 | 58.50 & 1.29 |
Piston sizes larger than Ø34.9mm
| Spring Load | Part number | Free Length & Wire Ø (mm) |
| 4 lbs | CP2667-105 | 39.88 & 1.22 |
| 7 lbs | CP2667-113 | 39.88 & 1.29 |
| 9 lbs | CP2667-125 | 70.36 & 1.29 |
| 12 lbs | CP2667-154 | 70.36 & 1.49 |
Anti-knockback Spring Kits
| Caliper Type | Part number | Contents |
| 4 Piston | CP6518-4LBSS | 4x CP2632-113 |
| CP6518-4LBLL | 4x CP2667-105 | |
| CP6518-7LBLL | 4x CP2667-113 | |
| CP6518-9LBLL | 4x CP2667-125 | |
| 6 Piston | CP6518-4LBSSL | 4x CP2632-113 & 2x CP2667-105 |
| CP6518-7LBSSL | 4x CP4100-121 & 2x CP2667-113 | |
| CP6518-9LBSSL | 4x CP3432-134 & 2x CP2667-125 |
Brand:
AP Racing
Manufacturer Part Number:
CP2632-113, CP4100-121, CP3432-134, CP2632-129, CP2667-105, CP2667-113, CP2667-125, CP2667-154, CP6518-4LBLL, CP6518-4LBSSL