Sealed Bearings

FITS MANY PINARELLO ROAD BIKES USING NON-TAPERED 1-1/2" BEARINGS

Inner x Outer x Depth (mm): 40 x 52 x 7
Inch Dia: 1 - 1 / 2"
Angle / Chamfer: Non
Material: Chromium Steel GCR15 (Race & Balls)

LOWER BEARING FOR TREK MADONE 2011 ONWARDS & TREK DOMANE (ENDURO BEARING)
Also known as: ACB 6808 SS, ACB4051K SS, MR006
See ACB4051KK-BO as alternative, which is same size but with black oxide (BO) coating.

Inner x Outer x Depth (mm): 40 x 51 x 6.5
Inch Dia: 1 - 1 / 2"
Angle / Chamfer (Deg): 36 / 36
Material: Stainless Steel

USED ON Wilier Bikes - Superslim Bearing!
Inner x Outer x Depth (mm): 39 x 46.9 x 7

Inner x Outer x Depth (mm): 40 x 49 x 6
Angle / Chamfer (Deg): 45 / 45
Note: Fits Van Rysel road bike 2023-2024

LOWER BEARING FOR TREK MADONE 2011 ONWARDS & TREK DOMANE
Same size as: ACB3636-150S, ACB 6808 SS, ACB4051K SS, MR006
Equivalent to Trek Part: W540243

Inner x Outer x Depth (mm): 40 x 51 x 6.5
Inch Dia: 1 - 1 / 2"
Angle / Chamfer (Deg): 36 / 36
Material: Steel with Black Oxide Finish

Note: the black oxide finish provides a corrosion resistance surface

NOTE, This direct equivalent to FSA part ref MR261A (160-0181000000) - fits Whyte E-Lyte

Inner x Outer x Depth (mm): 42 x 51.8 x 7
Inch Dia: 1 - 1 / 2”
Angle / Chamfer (Deg): 45 / 45

AI52/Ai52 Upper Headset Bearing, Note the lower bearing is our part ref 'P16'

Inner x Outer x Depth (mm): 42 x 52 x 7
Inch Dia: 1 - 1 / 2”
Angle / Chamfer (Deg): 45 / 45
Note: Same fit as Acros AC4252

Specialized Part Ref: S162500005

Used on Venge frame 2016-2018 - upper only
Venge 2019 Onwards  - upper and lower
Note, older Venge frame upto 2015, see part number MH-P21 for lower bearing. 
If in any doubt, please check dimensions of current bearing for comparison.

Inner x Outer x Depth (mm): 40.5 x 49.5 x 6.5
Inch Dia: 1 - 1 / 2”
Angle / Chamfer (Deg): 45 / 45

Specialized Part Ref: S162500005

Used on Venge frame 2016-2018 - upper only
Venge 2019 Onwards  - upper and lower
Note, older Venge frame upto 2015, see part number MH-P21 for lower bearing. 
If in any doubt, please check dimensions of current bearing for comparison.

Inner x Outer x Depth (mm): 40.5 x 49.5 x 6.5
Inch Dia: 1 - 1 / 2”
Angle / Chamfer (Deg): 45 / 45

NOTE, The Planet X Nanolight, Ribble R872, Ribble Stealth and De-Rosa R839 have used this lower bearing (but please check your lower bearing size to make sure it is the 51.5mm as we haven't had it confirmed that all these models ALWAYS used this headset/bearing size for the life of this model range)

Inner x Outer x Depth (mm): 40 x 51.5 x 7
Inch Dia: 1 - 1 / 2”
Angle / Chamfer (Deg): 45 / 45