TRIUMPH 57-2176 Mainshaft High Gear T150 26T

( Manufacturer Part Number: 57-2176 ), ( Part Type: Gear ), ( Vintage Part: Yes ), ( Country Of Origin: United Kingdom )

Review TRIUMPH Mainshaft High Gear 26t fits ROCKET A75 BSA

The **Triumph 57-2176 T150 Rocket BSA A75 Mainshaft High Gear 26T** is a meticulously crafted, high-performance aftermarket gearset designed exclusively for the legendary Triumph T150 Rocket, a motorcycle renowned for its raw, unfiltered power and timeless British engineering. This precision-machined mainshaft assembly represents the pinnacle of tuning for the BSA A75 engine, offering a direct route to unlocking the full potential of this iconic twin-cylinder powerplant. Engineered with a **26-tooth high gear** on the mainshaft, this gearset is tailored to maximize throttle response and top-end speed while maintaining the aggressive, rev-happy character that enthusiasts adore in the T150. The **T150 Rocket** a nod to the original BSA Rocket, a machine celebrated for its fearless, high-revving nature benefits immensely from this upgrade, as the larger 26-tooth gear reduces the engine s revving range, allowing it to sustain higher speeds with greater efficiency and torque delivery. Crafted from hardened steel and finished to exacting tolerances, this gearset ensures durability and reliability, even under the demanding conditions of aggressive riding or track use. Whether you're chasing the wind on a long-distance run or pushing the limits on a twisty road course, the **57-2176 T150 Rocket BSA A75 Mainshaft High Gear 26T** transforms the T150 into a more refined yet still brutally efficient machine, bridging the gap between raw power and practical performance. For the purist seeking to preserve the soul of the BSA A75 while gaining a competitive edge, this gearset is an indispensable upgrade a seamless blend of heritage and high-performance engineering.

### **Pros and Cons of Buying a Triumph 57-2176 T150 Rocket BSA A75 Mainshaft High Gear 26T**

#### **Pros**

1. **Classic British Motorcycle Heritage** This is a rare and highly sought-after piece of motorcycle history, built by Triumph and BSA in the 1950s. It represents the golden era of British motorcycle engineering, with a design that remains iconic.

2. **Strong Engine and Performance** The **A75** engine (a BSA design) is a robust parallel-twin with a displacement of 733cc. When properly maintained, it can produce **40 50 horsepower**, which was impressive for its time. The **high gear mainshaft (26T)** suggests it may have been modified for better top-end performance, making it faster than stock models.

3. **Durability and Reliability (When Well-Maintained)** BSA and Triumph engines of this era were built to last, especially if they have been kept in good condition. Many of these bikes still run today with proper care.

4. **Modification Potential** The **T150 Rocket** was a high-performance variant of the BSA A75, often featuring **higher compression, larger carburetures (e.g., Amal Concentric or Dell Orto), and stronger components**. This makes it a good candidate for restoration or further tuning.

5. **Collectible and Investment Value** Due to its rarity and historical significance, this bike is highly collectible. Well-preserved examples can appreciate in value over time, especially if they are part of a complete set (e.g., with original paperwork, paint, and components).

6. **Unique Aesthetic** The **T150 Rocket** had a distinctive **long-tail design, chrome detailing, and aggressive styling** that set it apart from standard BSA/Triumph models. It s a standout bike for enthusiasts who appreciate classic racing aesthetics.

7. **Potential for Restoration Projects** If you enjoy working on motorcycles, this could be an exciting project. Restoring a **T150 Rocket** to original or even improved condition can be deeply rewarding.

---

#### **Cons**

1. **Extensive Restoration Required** Most examples of this bike will be **stripped, rusted, or in poor mechanical condition**. Restoring it to full working order requires **significant time, money, and mechanical skill**, especially if the engine, transmission, or frame is corroded.

2. **High Cost of Restoration** Parts for a **1950s BSA/Triumph** can be expensive, particularly if they are original or aftermarket reproductions. Common issues include:

- **Rust in the engine block, crankcase, or transmission**

- **Worn-out bearings, seals, and gaskets**

- **Carburetor and ignition system deterioration**

- **Frame and fork wear (especially if it was a race bike with heavy use)**

- **No disc brakes** (likely drum brakes, which are less effective in wet conditions).

- **Basic suspension (if any)** Many T150 Rockets had **hardtail frames or simple springer forks**, leading to a rough ride.

- **No modern fuel injection or electronic ignition** Carburetors and points-based ignition require frequent tuning.

- **No ABS, traction control, or modern safety features**.

4. **Riding Experience Limitations** The **high gearing (26T mainshaft) and heavy weight** (likely **200 lbs dry**) make it **less forgiving on modern roads**. The bike was designed for **circuit racing or fast road use in the 1950s**, not today s highways.

5. **Fuel and Emissions Issues** Many modern areas have **emissions regulations** that may not allow classic bikes to be ridden legally without modifications (e.g., catalytic converters, smog checks). Some countries require **homologation or special permits** for pre-1970 bikes.

6. **Limited Availability of Parts** While BSA and Triumph parts are available, **exact matching components (especially for the T150 Rocket variant) can be hard to find**. Some parts may need to be **remanufactured or sourced from other brands** (e.g., Norton, Velocette).

7. **High Insurance Costs** Classic bikes, especially rare and high-performance models like this, can be **expensive to insure**. Theft risk is also a concern due to their value.

8. **Maintenance Challenges** Keeping a **50 year-old engine running smoothly** requires **regular oil changes, valve adjustments, and ignition tuning**. Many modern mechanics may not have experience with these engines.

---

### **Ending Conclusion**

The **Triumph 57-2176 T150 Rocket BSA A75 (26T mainshaft)** is a **fantastic piece of motorcycle history** with strong engineering roots and a cult following. It is **ideal for collectors, restorers, and enthusiasts who appreciate classic racing bikes** and are willing to invest the time and money into bringing it back to life.

However, it is **not a practical daily rider** for most people today. The **high cost of restoration, lack of modern comforts, and potential legal/insurance hurdles** make it more of a **project bike or showpiece** than a reliable street machine.

If you are **passionate about vintage motorcycles, have mechanical skills, and are prepared for a long-term commitment**, this bike could be an **incredible investment in both nostalgia and potential value appreciation**.

If you **prioritize convenience, modern safety, and ease of use**, then a **restored classic (like a Triumph Bonneville or BSA Gold Star) or a modern retro-style bike** might be a better choice.

---

### **Recommendation**

You are **serious about restoring a classic racing motorcycle** and have the **time, budget, and mechanical knowledge** to do so properly.

You **appreciate the historical significance** and want to own a **rare, high-performance British twin**.

You plan to **display it, ride it occasionally on private tracks or classic bike events**, and are okay with **compromises in comfort and modern safety**.

You are **prepared for the possibility of it appreciating in value** over time.

You need a **reliable, daily-ridable motorcycle** with modern features.

You **cannot commit to a long-term restoration project**.

You **lack mechanical experience** or access to specialized tools/knowledge.

You **cannot afford unexpected repair costs** (which are likely given its age).

- A **restored Triumph Bonneville or BSA Gold Star** (more practical, still classic, but easier to maintain).

- A **modern retro-style bike** (e.g., Kawasaki Vulcan S, Triumph Thruxton) if you want a **modern ride with vintage aesthetics**.

- A **fully restored T150 Rocket** (if you find one already completed by a trusted restorer).

If you proceed, **inspect it thoroughly (or have a mechanic do so) before purchasing**, and **budget for a full strip-down and rebuild** this is not a bike you can just "fix up" and ride. Enjoy the journey!

Details:

part #: 572176 prices

• $25.00-$229.99

specifications cyclevintagee:

• for models: A75, Bsa, Rocket
• for makes: Triumph
• mpn: 57-2176
• part type: Gear
• vintage part: Yes
• country of origin: United Kingdom

payments cyclevintagee:

• credit card: Visa
• wallet: Apple-pay
• other

general cyclevintagee:

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

shipping cyclevintagee:

• class: Standard, Economy
• cost: $0.00
• type: Calculated
• service: USPS Ground Advantage, UPS Ground Saver
• carrier: USPS, UPS
• transit: 3-7 Days

returns cyclevintagee:

• policy: No Returns

offer cyclevintagee:

• options: Ship-to-home
• availability: In Stock
• sold: 0
• quantity: 1
• started: February 16, 2026
• best offers: True

seller cyclevintagee:

• rating: 100.0%
• city: Denver, Colorado
• # reviews: 580

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