Frames with oversized lower headtubes and IS52/30 integrated cups offer maximum steering stiffness. Our ceramic bearing set matches that performance priority — Grade 3 silicon nitride balls with DLC-coated races and ABEC-7 tolerances for the stiffest, smoothest steering response possible. Covers IS52 integrated lower cups paired with 30mm lower fork steerers.
What You Get
- ✓ Grade 3 Si₃N₄ ceramic balls — reduced steering friction from ride one
- ✓ DLC-coated chromium steel races for extended bearing life
- ✓ ABEC-7 precision tolerances for smooth, play-free steering
- ✓ Matched pair: upper and lower bearings included
- ✓ For oversized 52mm integrated lower cup applications
Technical Specifications
| Includes |
2 bearings |
| Seal Type |
Integrated contact seals |
| Tolerance |
ABEC-7 |
| Cup Diameter |
52mm |
| Fork Steerer |
30mm (1.5 inch) |
| Expected Life |
20,000–35,000 miles |
| Race Material |
52100 Chromium Steel, DLC Coated |
| Bearing Material |
Grade 3 Silicon Nitride (Si₃N₄) |
| Bearing Standard |
IS52/30 |
Compatibility
Frames with IS52 integrated headtube cups
1.5 inch straight or tapered lower steerer forks
Select Specialized, Trek, and Giant aero frames
High-stiffness endurance and racing frames with oversized headtubes