Bike Wheel Bearing - Codes and Sizes List

Wheel bearings look simple until one worn hub turns into a guessing game. The fastest way to find the right replacement is to match the bearing code stamped on the seal with the inside diameter, outside diameter, and width.

This index is built as a practical reference for wheel-bearing sizes commonly searched through the Bike Bearing Store wheel bearings range. Use it to identify the code, check the size in millimetres or inches, and match it against the bearing removed from the hub.

The size format used throughout is:

ID × OD × W

Inside diameter × outside diameter × width, measured in millimetres (some in inches)

Bearing codes are easiest to confirm when the seal is clean and readable.

Bike Wheel Bearing List

Bearing Code	Inner (mm)	Outer (mm)	Width (mm)
686	6	13	5
R4	6.350 (1/4")	15.875 (5/8")	4.978 (5/32")
688	8	16	5
698	8	19	6
608	8	22	7
689	9	17	5
699	9	20	6
608-9	9	22	7
609	9	24	7
R6	9.525 (3/8")	22.225 (7/8")	7.143 (9/32")
6700	10	15	4
6800	10	19	5
3800	10	19	8
6900	10	22	6
6000	10	26	8
16100	10	28	8
6200	10	30	9
6701	12	18	4
MR1218	12	18	5
6801	12	21	5
63801	12	21	7
3801	12	21	8
6901	12	24	6
12268	12	26	8
6001	12	28	8
6201	12	32	10
R8	12.700 (1/2")	28.575 (1-1/8")	7.938 (5/16")
13215	13	21	5
6802-14	14	24	5
6702	15	21	4
6802	15	24	5
15267	15	26	7
15268	15	26	8
152610	15	26	10
6902	15	28	7
15307	15	30	7
6002	15	32	9
6202	15	35	11
R10	15.875 (5/8")	34.925 (1-3/8")	8.73 (5/16")
16277	16	27	7
16287	16	28	7
163110	16	31	10
6703	17	23	4
6803	17	26	5
63803	17	26	7
3803	17	26	10
17287	17	28	7
6903	17	30	7
173010	17	30	10
173110	17	31	10
6003	17	35	10
18287	18	28	7
18307	18	30	7
19285	19	28	5
6804-19	19	32	7
190537	19.05	37	9
R12	19.05 (3/4")	41.28 (1-5/8")	11.11 (7/16")
6704	20	27	4
20307	20	30	7
203013	20	30	13
6804	20	32	7
6904	20	37	9
6004	20	42	12
60/22	22	44	12
22371	22.2	37	8/11.5
23327	23	32	7
2437	24	37	7
24378	24	37	8
6705	25	32	4
6805-6mm	25	37	6
6805-7mm	25	37	7
6905	25	42	9
2753765	27.5	37	6.5
27537	27.5	37	7
29407	29	40	7
6706	30	37	4
30406	30	40	6
3040H7	30	40	7
6806	30	42	7
3041	30	41/44	11.2
6906	30	47	9
31437	31	43	7
314357	31	43.5	7
6707	35	44	5
6807	35	47	7
6708	40	50	6
6808	40	52	7
6709	45	55	6
6809	45	58	7
6909	45	68	12
6710	50	62	6
6810	50	65	7

Measure the bearing with a vernier calliper