Behold the Humble Scooter Wheel Bearing!
The scooter wheel bearing is used to minimize the friction of a wheel spinning on its axle. The scooter bearing is found on everything from kids' skateboards and kick scooters, up through mobility scooters and power chairs, and onto the urban commuters' street-legal motor scooter.

All scooter types use between two and six turning wheels, casters, or anti-tippers; so these scooter wheel bearings are as ubiquitous a type of parts as can be found. Each scooter wheel will usually have two bearings; one on either side of the hub or rim.

Although primitive forms of roller bearings have been around since antiquity, the earliest ball bearings may have had their beginnings with Leonardo di Vinci. Regardless of its historical origin, the modern steel scooter wheel bearing is one of the most frequently replaced items on any scooter type, model, or manufacturer.


A Guide to Scooter Wheel Bearing Codes & Standards
To the uninitiated, simple scooter wheel bearings are almost obscured behind a bewildering variety of numeric code designations. Once deciphered, the series of numbers in front of the scooter bearing's name can provide a lot of information about that specific type of scooter wheel bearing.

Here is a typical example: 6001ZZ
6 = Type Code
0 = Series
01 = Bore Size
ZZ = Suffix

Scooter Wheel Bearing Type Code Definitions:
1 - Self-aligning ball bearing
2 - Wide self-aligning ball bearing
3 - Double-row angular contact ball bearing
4 - Double-row ball bearing
5 - Thrust ball bearing
6 - Single-row deep groove ball bearing
7 - Single-row angular contact bearing
16 - Thin section single-row deep groove ball bearing
22 - Self-aligning roller bearing
23 - Wide self-aligning roller bearing

Series: (Identifies the lightness or heaviness of the scooter bearing)
0 - Extra Light
1 - Extra Light Thrust
2 - Light
3 - Medium
4 - Heavy
7 - Not Sure
8 - Extra Thin Section
9 - Very Thin Section

Bore Sizes (in mm):
For most scooter wheel bearings, the bore size can be calculated by adding the 3rd and 4th digits together and multiplying the result by 5. However, there are a few exceptions to this rule, as follows:
00 = 10 mm
01 = 12 mm
02 = 15 mm
03 = 17 mm

Suffix Meanings:
Z - Single Shielded
ZZ - Double Shielded
RS - Single Sealed
2RS - Double Sealed
V - Single Non-contact Seal
VV - Double Non-contact Seal
DDU - Double Contact Seals
NR - Snap Ring and Groove
M - Brass Cage
C3 - This marking indicates a radial internal clearance greater than the standard clearance. A C3 scooter bearing will usually be fitted to equipment where there are large temperature differences between the inner and outer casings, therefore, sufficient clearance is needed to avoid early bearing failure.