ACB518H8 45°/45° Angular Contact Bicycle Headset Bearing 40×51.8x8mm
| Item No : | ACB518H8 / ACB518 |
| Size (d*D*B) : | 40×51.8×8 mm |
| Material : | Chrome Steel GCr15 |
| Lead Time : | 3-5 days |
| Weight : | 0.033KG |
| MOQ : | 50 pcs |
| Service : | Support Sample Testing |
⚙️Product Description:
The ACB518H8 is a premium Angular Contact Bearing (ACB) specifically designed for modern integrated bicycle headsets. Featuring exact dimensions of 40×51.8x8mm and dual 45-degree chamfers, it is the standard lower bearing for most 1.5-inch tapered steerer tubes. Built to handle the complex radial and axial forces generated during steering, it ensures crisp, predictable handling on any terrain. As an established B2B trading partner, our RMO brand supplies these essential headset components to global frame builders and bike shops. Furthermore, we leverage our expansive supply chain to source other renowned bearing brands to fulfill your specific OEM assembly requirements.
⚙️Product Features:
- Angular Contact Design: Internal ball tracks are specially angled to simultaneously absorb vertical impacts (from the road) and lateral thrust (from steering), drastically increasing bearing longevity.
- 45°/45° Precision Chamfers: The inner and outer rings are accurately machined with 45-degree angles for a perfect, creak-free drop-in fit directly into the frame’s head tube and crown race.
- Sweat & Weather Resistance: Equipped with durable rubber seals to safeguard the internal steel balls from corrosive rider sweat, rain, and energy drink spills.
- B2B Sourcing Advantage: Maximize your workshop’s margins with our highly competitive RMO brand inventory, or request custom bulk orders featuring top-tier international labels.
⚙️Product Application:
Essential for steering stability and smoothness, the ACB518H8 is primarily used in:
- Lower headset assemblies for 1.5″ tapered forks (Road, MTB, Gravel).
- Integrated (IS) and Zero Stack (ZS) head tubes requiring 51.8mm OD bearings.
- Carbon fiber frame building and custom bicycle manufacturing.
- Professional steering system upgrades and routine headset maintenance.
⚙️Precautions:
| 1. Keep clean | 2. Use with caution | 3. appropriate tool | 4. Hot-loading | 5. Be careful of rust |
| Dust will have a bad effect on the bearing, so keep the surrounding clean. | Strong impact during use can easily cause scratches and indentations. | Avoid replacing existing tools, and use appropriate tools. | Bearings are precision parts, so hot installation is recommended. | Sweat on your hands during operation will cause rust, so it is best to wear gloves. |
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⚙️Obtain Certificate:
About Rimao
Since its establishment in 2011, Rimao Bearing has combined international vision with local wisdom and injected innovative ideas into every bearing and pulley with its profound industry accumulation and unremitting pursuit of technology. We have not only passed CE and ROHS certification, but also set a new benchmark in the industry and led the development trend of the bearing industry.
We are not just a ball bearing and roller bearing importer and wholesaler. We provide real solutions to help you achieve the product and design goals set by your customers. With more than 20 years of production and sales experience, tens of thousands of models and specifications, we look forward to cooperating with you!
⚙️Technical Parameters:
| Model No. | |
| Dimensions | |
| Bearing Type | Angular Contact Bearing |
| Angles | 45° Inner Chamfer / 45° Outer Chamfer |
| Material | |
| Seal Type | 2RS (Double Rubber Seals) |
| Steerer Fitment | 1.5″ Tapered Lower |
| Weight per Piece | |
| Brand | |
| Package | |
| Lead Time | |
| Shipping | |
| Payment | 100% TT, or 30% TT In Advance, 70% TT After Finished Production |
⚙️Headset Bearing List:
| Bearings No. | d*D*H(mm) | Weight (G) |
| ACB305418H6.3-45/45 | 30.5*41.8*6.3 | 30 |
| ACB307418H7.7-45/45 | 30.7*41.8*7.7 | 30.1 |
| ACB3144H6.3-45/45 | 31.4*44*6.3 | 30.2 |
| ACB31448H6.3-45/45 | 31.4*44.8*6.3 | 32.6 |
| ACB32438H7-45/45 | 32.4*43.8*7 | 23 |
| ACB32418H6-45/45 | 32.8*41.8*6 | 16 |
| ACB3344H6-36/45 | 33*44*6 | 21 |
| ACB33438H7-30/45 | 33.05*43.8*7 | 23.8 |
| ACB3345H7-45/45 | 33.5*45*7 | 26.2 |
| ACB3446H7-45/45 | 34.1*46*7 | 25 |
| ACB34468H7-45/45 | 34.1*46.8*7 | 27.7 |
| ACB34469H7-45/45 | 34.1*46.9*7 | 28 |
| ACB3544H5-90/90 | 35*44*5 | 16 |
| ACB3544H5.5-36/45 | 35*44*5.5 | 32 |
| ACB354535H7.3-45/45 | 35*45.35*7.3 | 22.3 |
| ACB3547H8-45/45 | 35*47*8 | 29.9 |
| ACB36458H6.5-45/45 | 36.8*45.8*6.5 | 18.9 |
| ACB3748H7-45/45 | 37*48*7 | 27 |
| ACB37489H6.5-36/45 | 37*48.9*6.5 | 25.9 |
| ACB3749H6.5-36/45 | 37*49*6.5 | 25.25 |
| ACB3749H7-36/45 | 37*49*7 | 28.1 |
| ACB3749H7-45/45 | 37*49*7 | 28.8 |
| ACB4051H6.5-36/36 | 40*51*6.5 | 24.8 |
| ACB4051H8-36/45 | 40*51*8 | 29.3 |
| ACB4051H7-45/45 | 40*51*7 | 31 |
| ACB40515H7-45/45 | 40*51.5*7 | 30.8 |
| ACB40518H7-45/45 | 40*51.8*7 | 30.8 |
| ACB40518H8-36/45 | 40*51.8*8 | 32.6 |
| ACB40518H7.5-36/45 | 40*51.8*7.5 | 33 |
| ACB40518H8-45/45 | 40*51.8*8 | 33.1 |
| ACB40518H8-90/90 | 40*51.8*8 | 33.1 |
| ACB40519H7-45/45 | 40*51.9*7 | 29.6 |
| ACB40519H8-45/45 | 40*51.9*8 | 32.6 |
| ACB4052H6.5-36/45 | 40*52*6.5 | 29.2 |
| ACB4052H7-90/90 | 40*52*7 | 30.9 |
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