SHIMANO Y64338101 Nos Braze Downtube Shifter Lever Boss 689228195455 Curved

( Brand: Shimano ), ( Manufacturer Part Number: Y64338101 ), ( Part Type: Lever ), ( Color: Bright Shiny Finish ), ( Country Of Origin: Japan ), ( Vintage: Yes ), ( UPC: 689228195455 )

Review SHIMANO Nos Vintage Braze On Downtube Shifter Lever Boss Curved Pair

The **Shimano Y64338101 NOS (New Old Stock) Braze-On Downtube Shifter Lever Boss, Curved** is a meticulously preserved, high-performance component designed for cyclists seeking both reliability and precision in their mountain biking or gravel riding experience. This vintage lever boss, originally crafted for Shimano s legendary downtube shifter systems, exemplifies the brand s engineering excellence from an era when durability and functionality were paramount. The curved design of the lever boss ensures a natural, ergonomic grip, allowing riders to modulate their shifting with confidence and control, even under demanding conditions. Crafted from high-grade aluminum, the component is built to withstand the rigors of off-road riding, offering a robust yet lightweight solution that complements Shimano s reputation for innovation. The braze-on design enables seamless integration into custom or restored frames, making it a sought-after piece for builders and restorers aiming to recreate the classic aesthetic and performance of older Shimano systems. Whether used in a full rebuild or as a standalone upgrade, this NOS lever boss carries the authenticity of its original manufacturing standards, ensuring a smooth, responsive shifting experience that bridges the gap between vintage charm and modern performance. Its timeless design and uncompromising quality make it a prized addition for enthusiasts who appreciate both the history and the functionality of Shimano s legendary components.

The Shimano Y64338101 is a No-Name-On-Stock (NOS) braze-on downtube shifter lever boss, specifically designed for curved handlebars. Below is a detailed analysis of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the Shimano Y64338101 NOS Braze-On Downtube Shifter Lever Boss**

1. **Compatibility with Curved Handlebars**

The curved design ensures a proper fit for drop bars, allowing shifters to mount securely without misalignment. This is critical for ergonomic and functional performance.

2. **Durability and Build Quality**

Shimano components are known for their robust construction, often using high-quality materials like aluminum or reinforced plastics. The braze-on design is designed to withstand repeated stress from shifting and handlebar vibrations.

3. **Reliability**

Shimano parts are widely tested and used in professional and amateur cycling, reducing the risk of premature failure. The lever boss is a critical component that, when properly installed, ensures smooth shifting and longevity of the shifter mechanism.

4. **Aftermarket Availability**

As a Shimano part, it is easy to find replacement or compatible components if needed. The NOS status means it may be slightly older but still fully functional, avoiding potential issues with newer models that might have design flaws.

5. **Aesthetic and Functional Fit**

The curved shape aligns with the ergonomics of drop bars, improving grip and reducing hand fatigue during rides. This is particularly useful for road, gravel, or endurance cycling where comfort is key.

6. **Compatibility with Shimano Groupsets**

It is designed to work seamlessly with Shimano s shifter levers (e.g., Sora, 105, Ultegra, Dura-Ace), ensuring consistent performance and compatibility with other components in the groupset.

7. **Cost-Effective for NOS Parts**

NOS parts can be cheaper than new ones, offering a budget-friendly option for restorations or upgrades without sacrificing quality.

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### **Cons of the Shimano Y64338101 NOS Braze-On Downtube Shifter Lever Boss**

1. **Age and Wear**

Being a NOS part, it may show signs of wear, such as slight discoloration, minor surface scratches, or potential corrosion if stored improperly. While functional, it may not look as pristine as a new part.

2. **Potential Lack of Warranty**

NOS parts are typically sold without a warranty, meaning you bear full responsibility for any defects or failures. This can be a risk if the part is not thoroughly inspected before purchase.

3. **Fitment Challenges**

While designed for curved handlebars, improper installation (e.g., misalignment or incorrect brazing) can lead to shifting issues or premature wear. Precision is required during installation to avoid problems.

4. **Limited Availability of Replacement Parts**

If the part fails or needs replacement, finding an exact NOS match may be difficult, especially for older models. You might need to source a compatible alternative, which could differ slightly in design.

5. **Compatibility with Non-Shimano Systems**

If you are using a mixed-brand setup (e.g., Shimano shifters with non-Shimano brake levers), compatibility might not be guaranteed. The lever boss must align perfectly with the brake lever s mounting system.

6. **Potential for Counterfeit Parts**

The NOS market can sometimes include counterfeit or refurbished parts that are mislabeled. It s important to purchase from a reputable seller with a clear return or inspection policy to avoid receiving a fake or damaged item.

7. **Maintenance Requirements**

Like all mechanical parts, the lever boss and associated components (e.g., cables, housing) require regular maintenance (lubrication, cleaning) to ensure smooth operation. Neglecting maintenance can lead to shifting issues or failure.

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### **Conclusion**

The Shimano Y64338101 NOS braze-on downtube shifter lever boss is a high-quality, reliable component for curved handlebars, offering durability, compatibility with Shimano groupsets, and ergonomic benefits. Its NOS status provides a cost-effective option for cyclists looking to restore or upgrade their setup without compromising performance. However, potential drawbacks include the risk of wear, lack of warranty, and the need for careful installation and maintenance. The part is best suited for cyclists who prioritize functionality and are willing to invest time in ensuring proper fitment and upkeep.

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### **Recommendation**

If you are restoring a bike or upgrading a Shimano-equipped setup with curved handlebars, the **Shimano Y64338101 NOS braze-on downtube shifter lever boss is a strong choice**, particularly if you:

- Have experience with bike maintenance or are working with a mechanic to ensure proper installation.

- Are purchasing from a trusted seller who offers inspections or returns.

- Plan to maintain the component regularly to prolong its lifespan.

For new builds or high-end setups where aesthetics and warranty are priorities, consider a **new Shimano part** (e.g., the updated version of this lever boss) to avoid potential wear or compatibility issues. If budget is a concern and you are confident in the part s condition, the NOS option provides excellent value. Always inspect the part thoroughly before installation to confirm it meets your needs.

Details:

Please see all pics. More pics available upon request. They are curved to follow the contour of downtube. Once the package has been given to USPS or other carrier, I have no control over how they process it, or amount of time it takes for move through their system get you.

Original Shimano part number 643 3810-1. NOS, in very nice condition. These have a bright finish.: Pair of NOS vintage Shimano downtube shifter lever base bosses.

Shipping in the USA is by USPS.

part #: y64338101 prices

• $8.35-$13.40

specifications vintagebikepartiz:

• brand: Shimano
• mpn: Y64338101
• part type: Lever
• color: Bright Shiny Finish
• country of origin: Japan
• vintage: Yes
• upc: 689228195455

general vintagebikepartiz:

• Cycling > Vintage Cycling > Vintage Bicycle Parts

offer vintagebikepartiz:

• quantity: 1
• started: March 7, 2026
• sold: 0
• availability: In Stock
• options: Ship-to-home

seller vintagebikepartiz:

• # reviews: 2042
• rating: 100.0%
• city: Asheville, North Carolina

payments vintagebikepartiz:

• wallet: Paypal
• credit card: Diners-club
• other

returns vintagebikepartiz:

• policy: No Returns

shipping vintagebikepartiz:

• class: Standard
• type: Fixed
• transit: 10-16 Days
• carrier: USPS
• service: USPS Ground Advantage
• cost: $0.00

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