BSA 66-3141 Transmission Shaft Gear B34 24-4231

( Brand: Bsa ), ( Manufacturer Part Number: 66-3141 ), ( Part Type: Transmission Shaft Gear )

Review BSA B34 Transmission Main Shaft Part Tooth Gear fits A10 A7 B32 2020

The **BSA 66-3141 A10 A7 B34 B32 Transmission Shaft (24-4231 20 Gear)** is a precision-engineered component designed specifically for BSA (Birmingham Small Arms Company) motorcycles, particularly those equipped with the iconic 650cc parallel-twin engine, such as the BSA Gold Star, A65, or other models featuring the A10/A7 transmission case variants. This transmission shaft is a critical part of the motorcycle s drivetrain, responsible for transferring power from the engine s output shaft to the gearbox, ensuring smooth and reliable operation across a range of speeds and loads. Crafted from high-grade steel, this shaft is heat-treated and dynamically balanced to withstand the stresses of high torque and continuous use, making it a durable and long-lasting solution for both original equipment and restoration projects.

The **24-4231 20 Gear** designation indicates that this shaft is paired with a 20-tooth gear, which meshes seamlessly with the corresponding gear in the transmission case, facilitating precise gear engagement and reducing wear on the splines and bearings. The **A10/A7** transmission case variants refer to specific BSA models that utilize this particular shaft configuration, ensuring an exact fit without the need for modification. The **B34/B32** identifiers likely correspond to the shaft s spline pattern or bearing type, which are optimized for the BSA transmission s internal geometry, allowing for smooth operation while maintaining proper alignment and reducing backlash.

For enthusiasts and mechanics working on BSA motorcycles, this transmission shaft is an essential replacement part for those experiencing wear, damage, or failure in the drivetrain. Whether addressing a seized shaft, replacing a worn component, or upgrading an older bike with a restored transmission, this shaft delivers the reliability and performance expected from BSA s legendary engineering. Its compatibility with the **24-4231** gear assembly ensures that the motorcycle s shifting remains crisp and the power delivery remains consistent, whether cruising on open roads or navigating tight corners. Proper installation requires careful attention to alignment, lubrication, and torque specifications to maximize its lifespan and maintain optimal transmission function.

### **Pros and Cons of buying a BSA 66-3141 A10/A7 B34/B32 Transmission Shaft (24-4231 20 Gear)**

1. **Compatibility with Classic Motorcycles** This transmission shaft is designed for BSA Gold Star and other classic British motorcycles, ensuring a precise fit for models requiring this specific part.

2. **High-Quality Construction** BSA parts are known for durability, often built to withstand heavy use, especially in vintage or restored bikes.

3. **Aftermarket Availability** While not always new, this part is commonly found in aftermarket and restoration supply chains, making it easier to source than rare OEM replacements.

4. **Performance Reliability** If the original shaft was worn or damaged, replacing it can improve gear shifting smoothness and reduce internal wear in the transmission.

5. **Restoration Value** For collectors and enthusiasts, using genuine or high-quality aftermarket parts enhances the authenticity and value of a restored BSA motorcycle.

6. **Ease of Installation** Many BSA transmissions share similar designs, and with the right tools, this shaft can be installed by experienced mechanics or DIYers.

1. **Age-Related Wear** If purchasing a used or aftermarket part, there may be signs of wear, such as pitting, cracks, or bent splines, which could lead to premature failure.

2. **Limited Availability** Unlike mass-produced modern parts, BSA components can be harder to find, especially in newer or less specialized shops.

3. **Cost Considerations** While not excessively expensive, the price may be higher than generic aftermarket alternatives, particularly if sourced from reputable suppliers.

4. **Skill Dependency** Installing a transmission shaft requires mechanical expertise. Improper installation can lead to misalignment, premature wear, or even transmission failure.

5. **Potential Counterfeit Parts** Some aftermarket suppliers sell replicas that may not meet original specifications, risking poor performance or damage to the transmission.

6. **Maintenance Requirements** Even with a new shaft, regular lubrication and inspection are necessary to prevent binding or excessive wear over time.

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### **Conclusion**

The BSA 66-3141 transmission shaft is a crucial component for maintaining the performance and longevity of classic BSA motorcycles. Its pros such as compatibility, durability, and restoration value make it a worthwhile investment for enthusiasts committed to preserving or restoring their bikes. However, the cons including potential wear, limited availability, and installation challenges must be carefully considered.

If you are restoring a BSA or experiencing transmission issues, this part is a solid choice, provided you source it from a trusted supplier and ensure proper installation. For those on a tight budget or dealing with less critical models, alternatives may exist, but for authenticity and reliability, the BSA shaft remains a strong option.

### **Recommendation**

- **For Restoration Purposes:** Purchase from a reputable aftermarket supplier or a BSA specialist to ensure quality and compatibility.

- **For DIY Mechanics:** If installing yourself, follow the manufacturer s guidelines carefully and consider consulting a professional if unsure.

- **For Budget Considerations:** Compare prices across suppliers and check for used parts in good condition to balance cost and reliability.

- **For Long-Term Reliability:** Pair this part with regular maintenance, including proper lubrication and periodic inspections, to maximize its lifespan.

Ultimately, the decision depends on your priorities whether it s restoring authenticity, improving performance, or balancing cost and quality. For most BSA owners, the benefits outweigh the drawbacks when sourced and installed correctly.

Details:

Rays Brit bits and more .:: Listings By Rage biz. BSA A10 A7 B34 B32 TRANSMISSION MAIN SHAFT PART # 66-3141 24-4231 20 TOOTH GEAR, FOR SEMI UNIT GEARBOXES. PLEASE review all pictures of the item as it is considered a continuation.

part #: 663141 prices

• $63.64-$75.00

specifications cyclevintagee:

• for models: A10, A7, B32
• for years: 2020
• brand: Bsa
• mpn: 66-3141
• part type: Transmission Shaft Gear

seller cyclevintagee:

• city: Peck, Idaho
• rating: 100.0%
• # reviews: 7546

returns cyclevintagee:

• policy: No Returns

shipping cyclevintagee:

• transit: 5-8 Days
• service: USPS Priority Mail Small Flat Rate Box
• cost: $12.65
• type: Calculated
• carrier: USPS
• class: Expedited

general cyclevintagee:

• Parts Accessories > Motorcycle Scooter Parts Accessories > Other Motorcycle Scooter Parts Accessories
• condition: Used

offer cyclevintagee:

• options: Ship-to-home
• sold: 0
• started: March 14, 2026
• quantity: 1
• availability: In Stock

payments cyclevintagee:

• wallet: Paypal
• other
• credit card: Mastercard

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