Wholesale 21.5x37x9mm 6904-2RS Non-Standard Bore Bearings
| Item No : | |
| Size (d*D*B) : | 21.5x37x9mm |
| Material : | Chrome Steel GCr15 |
| Lead Time : | 3-5 days |
| Weight : | 0.018KG |
| MOQ : | 100 pcs |
| Service : | Support Sample Testing |
⚙️Product Description:
Trapped in a design dilemma where a standard 20mm bore is too tight, but 22mm is too loose? The 6904-2RS and 6904ZZ Non-Standard Bearings (21.5x37x9mm) provide the exact missing link for custom engineering and specialized aftermarket repairs. By featuring a highly specific 21.5mm internal diameter while maintaining the standard 37mm OD and 9mm width, this rare bearing eliminates the need for expensive shaft machining or unstable adapter sleeves. It is the highly sought-after solution for custom motorcycle axles, proprietary bicycle hubs, and specific industrial machinery repairs. As a specialized B2B bearing trading expert, we solve your hard-to-find component nightmares: stock up on our precisely manufactured RMO brand to dominate the custom parts niche, or let us source extremely specific global brands to meet your unique legacy equipment blueprints.
⚙️Product Features:
- 21.5mm Exact-Fit Architecture: Designed specifically for proprietary shafts and aftermarket modifications, bypassing the engineering headache of modifying standard OEM housings or altering shaft tolerances.
- Standard Outer Compatibility: Retains the classic 37x9mm exterior footprint of a standard 6904, allowing seamless drop-in replacements into existing bearing seats and hubs.
- Dual-Environment Customization: Opt for the 6904-2RS (Rubber Seals) to blockade gritty mud and water in outdoor customized vehicles, or the 6904ZZ (Metal Shields) for indoor specialist motors requiring strict clearance retention.
- High-Fidelity Manufacturing: Producing non-standard sizes requires master-level tooling. Ours are machined from premium 52100 (GCr15) chrome steel to ensure flawless concentricity despite the unconventional inner bore.
- Niche B2B Sourcing Power: We turn rare specs into readily available inventory. Bulk order our cost-effective RMO special series to build a monopoly in aftermarket parts, or request bespoke global sourcing for niche OEM lines.
⚙️Product Application:
This highly specialized 21.5mm bore makes the custom 6904 series the ultimate savior for:
- Aftermarket custom motorcycle wheels, modified axles, and specialized swingarms.
- Proprietary BMX and mountain bike hubs requiring specific non-standard bearing replacements.
- Specialized tuning equipment and modified automotive performance alternators.
- Legacy industrial machinery (textile/printing) where worn shafts have been specifically sleeved to 21.5mm.
- B2B auto-tuning parts distributors and retailers specializing in “hard-to-find” mechanical components.
⚙️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. |
 |  |  |  |  |
⚙️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. | 6904ZZ / 6904-2RS (61904 Series) |
| Size | 21.5x37x9mm |
| Bearing Type | Special Bore Thin Section Ball Bearing |
| Load Category | Light-to-Medium Duty / Aftermarket |
| Material | Chrome Steel GCr15 |
| Sealing Form | |
| Dynamic Load (Cr) | |
| Static Load (Cor) | ~ 2,450 N |
| Max RPM | ~ 17,000 RPM (Grease / Reference value for ZZ metal shield version) |
| Working Temperature | -20°C to +120°C |
| Brand | RMO Brand Wholesale & Global Brand Sourcing |
| Package | Individual plastic bag, plastic tube or original RMO brand box |
| Lead Time | 3-5 days for stock; 7-15 days for bulk orders |
| Shipping | Express (DHL/FedEx/UPS), Air Freight, Sea Freight |
| Payment | 100% T/T, or 30% T/T In Advance, 70% T/T After Finished Production |
leave a message
If you are interested in our products and want to know more details, please leave a message here, we will reply you as soon as we can.
You may also like
