SR CUSTOM School Triple Tour Bike 170MM CRANKS-50/42/36T-MOUNTAIN

( Brand: Sr Custom ), ( Manufacturer Part Number: CRANKS-50 ), ( Model: SR CUSTOM-A TRIPLE CRANKS-50 ), ( Type: Crank Set ), ( Color: Silver ), ( For Bike Type: Mountain Bike ), ( Vintage: Yes )

Review SR CUSTOM Rare Old School 170mm a Triple Cranks-50/42/36t-mountain Tour bike

The **SR Cranks 50 School 170mm Custom-A Triple Cranks (50/42/36T)** are a meticulously engineered set of mountain touring cranks designed to deliver unmatched performance, durability, and versatility for riders seeking a balance between climbing efficiency and all-day comfort. Built with a **170mm BCD (bolt circle diameter)**, these cranks are optimized for compatibility with a wide range of 68mm and 110mm spindle hubs, making them an ideal choice for hardtail and full-suspension mountain bikes, as well as gravel and touring rigs that demand both ruggedness and precision. The **50/42/36T triple chainring setup** offers a progressive gearing progression, allowing riders to tackle steep climbs with ease while maintaining efficient pedaling power in lower gears. The **50T large ring** provides a strong, direct drive for descending and cruising, while the **36T smallest ring** ensures effortless spinning on technical climbs or when navigating loose terrain, reducing fatigue over long distances. Crafted from **high-grade aluminum alloy**, these cranks are lightweight yet incredibly robust, capable of withstanding the demands of aggressive riding without compromising on smoothness or reliability. The **Custom-A design** incorporates a refined spindle interface and optimized chainline alignment, minimizing chain slap and ensuring a seamless transfer of power from the pedals to the drivetrain. Whether tackling steep switchbacks, carving through technical singletrack, or embarking on multi-day touring adventures, these cranks deliver the strength, efficiency, and adaptability required to conquer diverse riding conditions. Perfect for riders who demand both performance and longevity, the **SR Cranks 50 School 170mm Triple Cranks** are a testament to thoughtful engineering, blending precision engineering with the durability needed for the most demanding rides.

**Pros and Cons of buying a SR Cranks 50 School 170mm Custom-A Triple Cranks (50/42/36t) for a Mountain Touring Bike**

### **Pros**

1. **Versatility for Mixed Terrain**

The triple crankset (50/42/36t) provides a wide gear range, making it suitable for both road and light off-road conditions. This is ideal for a mountain touring bike, which may encounter gravel, dirt paths, or light trails alongside paved roads. The 50t large chainring offers strong climbing power, while the smaller chainrings (42t and 36t) allow for efficient pedaling on descents or flat sections.

2. **Compatibility with Existing Components**

If your bike already has a compatible bottom bracket (e.g., BB86, BB92, or standard square taper), these cranks should fit without major modifications. The 170mm Q-factor (distance between the chainring bolts) is standard for many touring bikes, ensuring a comfortable and familiar riding position.

3. **Durability and Strength**

SR Cranks are known for their robust construction, often using materials like aluminum or steel alloys that can withstand the stresses of touring, including heavy loads and rough terrain. The triple setup is less prone to wear compared to single-chainring systems in varied conditions.

4. **Cost-Effective Upgrade**

Compared to high-end cranksets, the SR Cranks 50 School offers a budget-friendly option that retains functionality. This makes it a practical choice for riders who want to improve their gearing without a significant investment.

5. **Ease of Maintenance**

Triple cranks are simpler to maintain than modern derailleur systems with multiple chainrings. They require fewer adjustments and are less likely to suffer from chain misalignment issues common in complex drivetrains.

6. **Compatibility with Touring Needs**

The large chainring (50t) is particularly useful for touring, as it provides strong pulling power when carrying heavy loads or tackling steep climbs. This is a key advantage over smaller chainrings found on many road bikes.

7. **Customization Options**

The "Custom-A" designation suggests that these cranks may offer some level of customization, such as bolt-on options for bottle cages, racks, or other touring accessories. This can enhance functionality for long-distance riding.

---

### **Cons**

1. **Weight**

Triple cranksets are generally heavier than single-chainring or double-chainring setups. This added weight may not be ideal if you prioritize lightweight efficiency, especially on long descents or in competitive riding scenarios. However, for touring, the trade-off in weight for versatility is often justified.

2. **Complexity of Gearing**

While the wide gear range is beneficial, it may require more frequent gear shifting, particularly when transitioning between road and off-road sections. This can be less efficient than a well-tuned single-chainring system, where the rider can focus on one smooth cadence.

3. **Chain and Derailleur Wear**

Triple cranksets can accelerate wear on the chain and rear derailleur due to the increased number of chainrings. This may lead to more frequent replacements of these components over time, adding to maintenance costs.

4. **Limited Modern Compatibility**

If your bike is equipped with modern drivetrain components (e.g., 1x drivetrains, electronic shifting, or wide-range cassettes), the triple crankset may feel outdated or less efficient. However, for a mountain touring bike, this is less of an issue since the focus is on durability and versatility rather than performance.

5. **Potential for Misalignment**

Triple cranks can sometimes experience chain misalignment, especially if the derailleur is not properly adjusted. This can cause chain drops or skipping, which may be more noticeable on rough terrain.

6. **Less Common in Modern Bikes**

While triple cranksets are still used in touring and some gravel bikes, they are less common in modern road or mountain bikes. This means finding replacement parts or compatible components might be slightly more challenging compared to single-chainring setups.

7. **Pedaling Efficiency on Flat Terrain**

The large chainring (50t) may feel less efficient for high-cadence pedaling on flat or downhill sections compared to a smaller chainring. Riders who prefer spinning at higher RPMs might find the 50t chainring less comfortable in these situations.

---

### **Conclusion and Recommendation**

The **SR Cranks 50 School 170mm triple crankset (50/42/36t)** is an excellent choice for a **mountain touring bike** if your priorities are **versatility, durability, and practicality** over lightweight efficiency or modern drivetrain performance. The wide gear range (50t for climbing, 36t for descents) makes it ideal for handling mixed terrain, including gravel, light trails, and paved roads. The robust construction ensures it can withstand the rigors of long-distance touring, heavy loads, and rough conditions.

However, if your primary focus is **minimal maintenance, weight savings, or modern drivetrain efficiency**, a single-chainring setup (e.g., 34-46t) or a double-chainring setup (e.g., 34-48t) might be more suitable. Single-chainring systems are simpler, lighter, and often more efficient for sustained riding, though they lack the climbing power of a large chainring.

For a **mountain touring bike**, the trade-offs of the triple crankset such as added weight, chain wear, and gearing complexity are generally outweighed by the benefits of **strong climbing ability, versatility, and compatibility with touring accessories**. If your bike s frame and bottom bracket are compatible, this crankset is a **solid, practical upgrade** that enhances the bike s capability for mixed-terrain touring without requiring a significant investment.

- You prioritize **durability, climbing power, and mixed-terrain versatility** over lightweight efficiency.

- Your bike s bottom bracket and frame are compatible with the crankset.

- You plan to use the bike for **touring, gravel riding, or light off-road adventures** alongside road sections.

- You are comfortable with **slightly heavier components and more frequent chain/derailleur maintenance**.

- You prefer **minimalist, lightweight setups** and are open to a single-chainring drivetrain.

- Your riding is primarily **road-focused** with minimal off-road sections.

- You anticipate **heavy use on smooth terrain** where a smaller chainring would be more efficient.

Details:

Rare Old School 170mm SR Custom-A Triple Cranks-50/42/36t-Mountain Tour-Bike Nice condition with scratches, oxidation and or light chain marks/wear.

part #: cranks50 prices

• $31.41-$69.99

specifications vintagebikepartiz:

• brand: Sr Custom
• mpn: Cranks-50
• model: Sr Custom-a Triple Cranks-50
• type: Crank Set
• color: Silver
• for bike type: Mountain Bike
• vintage: Yes

seller vintagebikepartiz:

• city: Cincinnati, Ohio
• rating: 99.3%
• # reviews: 9308

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general vintagebikepartiz:

• Cycling > Vintage Cycling > Vintage Bicycle Parts

offer vintagebikepartiz:

• availability: In Stock
• started: June 10, 2026
• options: Ship-to-home
• sold: 0
• quantity: 1

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