DT SwissDT Swiss 68DT Swiss 6903 Special Cartridge Bearing – 18x30x7mm – Each – 240S Front Hub Replacement

Plain-English Lead

This is a genuine DT Swiss 6903 Special cartridge bearing sized 18×30×7 mm. It is designed for specific DT Swiss 240S front hubs that use an 18mm outer diameter axle interface.

This listing is for one single bearing. Wheel, hub, and axle are not included.

Key Functional Details

• Genuine DT Swiss cartridge bearing
• Bearing number: 6903 Special
• Dimensions: 18×30×7 mm (ID×OD×Width)
• Precision sealed hub bearing
• Application: DT Swiss 240S front hubs (18mm axle versions)
• Sold individually (one bearing per unit)
• Service-level replacement part

Compatibility & Technical Notes

• Fits DT Swiss 240S front hubs with 18mm O.D. axle systems
• 18 mm inner diameter — must match axle interface
• 30 mm outer diameter — must match hub shell bore
• 7 mm width — must match hub bearing seat
• Not compatible with 6902 (15×28×7), 6904 (20×37×9), 6803 (17×26×5), or 6805 (25×37×7)
• Confirm bearing number stamped on original unit before ordering
• One bearing per unit — most front hubs require two
• Platform Type: MTB / Road (hub service part)

Service / Ownership Context

This bearing is press-fit into the hub shell. Proper bearing extraction and installation tools are required. Replace bearings when they feel rough, loose, or contaminated. For balanced performance, replacing both front hub bearings at the same time is recommended.

Fit & Use Signals

• Good Fit: You are servicing a DT Swiss 240S front hub with 18mm axle interface.
• Good Fit: Your original bearing measures 18×30×7 mm and is marked 6903.
• Not A Fit: Your hub uses a 15mm, 17mm, or 20mm axle system.
• Not A Fit: Your hub calls for 6902, 6803, 6805, or 6904 bearings.
• Not A Fit: You are looking for a complete hub or wheel — this is one bearing only.