Fulcrum Wheel Bearing Explained

How to decode the Fulcrum bearing part numbers, choose the right upgrade and avoid common pitfalls

Photo Copyright: Fulcrum

Two very different bearing systems in one brand

Hub architecture	What looks like	What can be upgraded
Cup-and-cone (loose balls)		Swap only the balls – replace the stock steel balls with Grade 3 Si₃N₄ ceramic balls while re-using the original cones, cups, retainers and seals.
Cartridge (sealed) bearings		Replace the entire cartridge bearing with a ceramic or steel unit of the same size.

Cheat-sheet: the cartridge bearing and loose ball bearing sizes

Fulcrum code	Bearing code - size (ID × OD × W mm)
R4-004, RP9-004	6903 – (17 × 30 × 7mm)
RT-004	6903-18/18307 – (18 × 30 × 7mm)
RS-011	6803 – (17 × 26 × 5mm)
4-R5-004, RWI-013	6001 – (12 × 28 × 8mm)
4-ERW-005	17306.5 - (17 × 30 × 6.5mm)

Fulcrum Code	Ball size
4-R1-007 4-RS-111 R0-003 RS-016	5/32" loose ball in each hub
RS-020	3/16" loose ball in each hub

Matching the wheel model to the bearings

Fulcrum Wheel Bearing Selector table below, detailing wheel models, production years, Fulcrum codes, hub bearing configurations, and bearing codes.

If your wheel model is not in the list, please send us an email: info@bikebearingstore.com.au. We will assist you in finding the match.

Special note for freehub bearing:  Option 1: 2 x 6803 - for Shimano/Campagnolo 9/10/11/12 Speed cassette, SRAM 9/10/11/12 XDR V2 cassette; Option 2: 1 x 6803 + 1 x 6903 - for SRAM 12 Speed XDR cassette.

Wheel Model	Fulcrum Codes (Hub)	Front Hub	Rear Hub	Freehub
Racing Zero (2005-2013) Racing 1 (2005-2013) Racing 3 (2005-2013) Racing Speed XLR (2010-2013) Racing Speed (2010-2011) Racing Light XLR (2010-2013) Racing Chrono (2010-2013) Red Wind XLR (2013) Red Wind XLR CX (2013) Speed 40 DB (2020) Speed 55T DB tubular (2020) Speed 40T DB tubular (2020)	4-R1-007 or 4-RS-111	30 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	30 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Quattro (2013) Racing Quattro CX (2013)	R4-004	2 x 6903	2 x 6903	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing 5 (2005-2013) Racing 5 CX (2013) Racing 7 (2005-2013) Racing 7 CX (2013) Red Wind (2013-2018)	4-R5-004 or RWI-013	2 x 6001	2 x 6001	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Zero (2014) Racing 1 (2014) Racing 3 (2014-2017) Racing Speed (2014-2016) Racing Speed 35 (2015-2016) Racing Speed XLR (2014-2016) Racing Speed XLR 80 (2015-2016) Racing Speed Disc (2015) Red Wind XLR (2014-2018) Red Wind XLR CX (2014-2016) Racing Light XLR (2014-2016)	4-R1-007 or 4-RS-111	30 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	30 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing 4/400 (2019-2020) Racing 5 (2014-2015) Racing 5 CX (2014-2015) Racing 5 LG (2015-2018) Racing 5 LG CX (2015-2016) Racing 7 (2015) Racing 7 CX (2015) Racing Quattro (2014-2015) Racing Quattro CX (2014-2015) Racing Quattro LG (2016-2018) Racing Quattro LG CX (2016) Racing Quattro Carbon (2016-2018) Racing S19 Light (2016) Wind 40/400 Clincher (2019-2024)	R4-004	2 x 6903	2 x 6903	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing 5 LG DB (2016-2017) Racing 4 DB / 400 DB (2018) Racing 5 DB / 500 DB (2018) Racing 6 DB / 600 DB (2018) Racing 7 DB / 700 DB (2018) Racing Quattro Carbon DB (2016-2017)	RT-004 (front), RP9-004 (rear)	2 x 6903-18/18307	2 x 6903	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing 6/600 (2019-2024) Racing 7 (2014) Racing 7 CX (2014) Racing 7 LG (2015-2018) Racing 7 LG CX (2015-2016) Racing S19 (2016)	4-R5-004 (front), R4-004 (rear)	2 x 6001	2 x 6903	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Sport (2014-2017) Racing Sport CX (2015-2016)	4-R5-004	2 x 6001	2 x 6001	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Speed Disc (2014-2016)	4-R1-007 or 4-RS-111	N/A	30 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Sport DB (2016) Racing S19 DB Light (2016) Wind 40/400 DB (2020-2023)	RP9-004	2 x 6903	2 x 6903	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Sport DB (2015-2016) Racing Sport DB CX (2015-2016)	RT-004 (front), 4-R5-004 (rear)	2 x 6903-18/18307	1 x 6001	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Zero (2016-2024) Speed 55T (2020) Speed 55C (2020) Speed 40T (2020) Speed 40C (2020)	R0-003/RS-016 (front), 4-RS-111 (rear)	26 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	30 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	Option 1: 2x6803 Option 2: 1x6803+1x6903
Rapid Red 5 650b DB (2020)	RT-004 (front), RP9-004 (rear)	2 x 6903-18/18307	2 x 6903	Option 1: 2x6803 Option 2: 1x6803+1x6903
Racing Zero Carbon DB (2024)	RS-020 (front), 4-RS-111 (rear)	30 x 3/16" Si₃N₄ Grade 3 Ceramic Balls	30 x 5/32" Si₃N₄ Grade 3 Ceramic Balls	Option 1: 2x6803 Option 2: 1x6803+1x6903

Special note for freehub bearing:  Option 1: 2 x 6803 - for Shimano/Campagnolo 9/10/11/12 Speed cassette, SRAM 9/10/11/12 XDR V2 cassette; Option 2: 1 x 6803 + 1 x 6903 - for SRAM 12 Speed XDR cassette.

Need help choosing? Send your wheel model and production year (a photo if possible) to info@bikebearingstore.com.au, and we’ll do the matching for you!