Acros Blocklock ZS44/28.6 Headset Top Assembly

The Blocklock ZS44/28.6 headset top assembly from Acros with a semi-integrated design for 1 1/8" head tubes and straight standard or tapered steerer tubes features the Blocklock function, which limits the steering angle to 164° and thus protects the top tube from damage. It also features double sealed stainless steel angular contact ball bearings, optimized headset grease and additional seals.

Use:

Designed for 1 1/8" upper head tube diameters combined with standard 1 1/8" or 1 1/8" - 1.5" tapered forks.

Specifications:

Application:

All Mountain, Cross Country, Enduro, Road, Gravel

Design:

Zero Stack (ZS)

Top Outer Diameter:

44 mm

Top Inner Diameter:

28.6 mm

Head Tube:

1 1/8"

Steerer Tube:

1 1/8" , 1 1/8" - 1.5" tapered

Technical Information:

Material:

aluminium

Bearings:

Stainless steel angular contact ball bearings, double sealed

Upper Insert Depth:

9 mm

Top Stack Height:

12.5 mm

Seals:

dual double lip seal

Features:

• Blocklock steering stop with 164°
• optimised headset grease
• dual double lip seal offers protection from moisture and dirt
• compression ring made of fibreglass-reinforced composite material 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)

Technology:

Blocklock
A special Acros headset innovation is the Blocklock System - a steering stop protection integrated into the headset, which helps to prevent frame damage caused by the handlebar hitting the top tube or the fork hitting the down tube of the frame. This makes it especially ideal for sensitive and expensive carbon frames. Cutouts in the upper headset cup accommodate the pivot on the headset cover. The steering unit's angle is limited mechanically, and the force is damped with small elastomers. The frame is thus largely protected from damage.

Manufacturer Number:

51.02.605R2S

Contents:

Acros Blocklock ZS44/28.6 Headset Top Assembly, consisting of:

• 1 x Blocklock headset cup with stainless steel bearings
• 1 x Blocklock headset cap
• 1 x Ahead cap
• 1 x star nut with aluminium bolt
• 1 x compression ring
• 1 x spare compression ring