Bearings

What are Bearings and what is their main purpose?

Bearings (in BMX almost exclusively "Sealed Bearings" or deep groove ball bearings) ensure that your hub rotates smoothly around the axle. They absorb radial and axial forces generated during riding and landing.

How is a Sealed Bearing constructed?

Outer Race & Inner Race

The tracks made of hardened steel.

Balls & Cage

The balls rotate between the races, held in place by a cage.

Seal

The colored cover (usually rubber/plastic -> "2RS") that keeps dirt out and grease in.

What types and codes are there?

Identification is usually done via a 4 or 5-digit code laser-etched onto the seal (e.g., 6902-2RS).

• The Number (e.g., 6902): Defines the geometric dimensions (Inner x Outer x Width).
• The Suffix (e.g., 2RS): Stands for "2 Rubber Seals", meaning sealed on both sides (standard in BMX).
• LB (Loose Ball): Loose balls on a cone (only found on very cheap entry-level hubs or old school).
• SB (Sealed Bearing): The standard maintenance-free industrial unit used in BMX.

Which bearing is right for my hub?

Since many manufacturers use different bearing sizes, there are two ways to choose:

1. By Hub Model: Choose a set explicitly listed for your hub (see product name).
2. By Code/Size: Remove your old bearing and read the code. If it's unreadable, measure with a caliper: Inner Diameter x Outer Diameter x Width.

Important Service Note: We cannot list every single bearing individually. If you need a specific size (e.g., 15267, 6802, 6903, etc.) that you cannot find: Contact us! We can procure most bearings for you on short notice.

How do I install Bearings?

1. Carefully remove the old bearing (tap out).
2. Clean the bearing seat in the hub and lightly grease it.
3. Press in the new bearing. IMPORTANT: Only apply pressure to the outer race! If you hit the inner race, you will destroy the bearing immediately.
4. Ideally, use a press tool or a matching socket from your toolbox that fits exactly on the outer race.

What do the specifications mean for bearings?

As requested, the technical details here are limited to the essentials: