Acros ZS55/30 Headset Bottom Assembly

The ZS55/30 headset bottom assembly from Acros with a semi-integrated design for 1.5" head tubes and straight standard steerer tubes is an all-round worry-free product. It impresses with double sealed angular contact ball bearings made of stainless steel, optimized headset grease and additional seals.

Use:

Designed for 1.5" lower head tubes combined with standard 1 1/8" forks.

Specifications:

Application:

All Mountain, Cross Country, Enduro, Road, Gravel

Design:

Zero Stack (ZS)

Bottom Outer Diameter:

55 mm

Bottom Inner Diameter:

30 mm

Head Tube:

1.5"

Steerer Tube:

1 1/8"

Technical Information:

Material:

aluminium

Bearings:

Stainless steel angular contact ball bearings, double sealed

Seals:

dual double lip seal

Features:

• optimised headset grease
• dual double lip seal offers protection from moisture and dirt
• crown race with vulcanized seal
• long durability with minimal maintenance

Standardized Headset Identification System (S.H.I.S.):

In order to clarify and bring uniformity to a sea of headset standards, manufacturers Acros, Cane Creek, Hope, Race Face, Reset Racing and Ritchey have agreed upon using a shared nomenclature, which will likely include more participating companies in the future. This system takes into account a combination of frame and fork dimensions. Both the top and bottom parts of the headset are marked by two alphanumeric identifiers. The first identifier indicates the type of headset (External Cup, Zero Stack, Integrated) and head tube diameter. The second identifier - separated from the first by a backslash - indicates the diameter of the steerer tube. When referring to a complete headset, the specifications of both top and bottom parts must be combined.

Nomenclature:

EC:

Bearings contained within headset cups that are located outside of the frame (External Cup)

ZS:

Bearings contained within pressed-in headset cups where the cup and bearings rest inside the frame (Zero Stack)

IS:

Bearings that fit directly into a bonded or machined interface that is integrated into the frame (Integrated)

Manufacturer Numbers:

black:

46.02.601R1S-1.1_8

red:

46.04.601R1S-1.1_8

blue:

46.05.601R1S-1.1_8

Contents:

Acros ZS55/30 Headset Bottom Assembly, consisting of:

• 1 x headset cup with stainless steel bearings
• 1 x 1 1/8" (30 mm) crown race