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SKU: CR3494

Shimano BB-UN300-K Square Taper Bottom Bracket for Chain Case, 68x117.5mm Hollow Spindle, JIS Square Taper Compatibility, Durable Black Construction, Suitable for English Thread Frames, Performance-Driven Cycling Component

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Description
Specifications

Upgrade your bicycle's drivetrain with the Shimano BB-UN300-K Bottom Bracket - a high-performance, durable component engineered for seamless pedal cadence and long-lasting reliability. Designed specifically for use with chain case setups, this bottom bracket features a robust hollow spindle construction combined with precision engineering to optimize power transfer and pedaling efficiency.

Constructed from high-quality materials, the Shimano BB-UN300-K boasts a 68x117.5mm spindle that fits JIS square-taper cranksets, making it compatible with a wide range of classic and modern bicycles. Its simple yet reliable English threaded interface ensures easy installation and maintenance, while the black finish adds a sleek, professional look to your bike's drivetrain.

Performance & Engineering:

- Hollow spindle for reduced weight without sacrificing strength, enhancing overall bike performance

- Precisely machined for excellent concentricity and smooth rotation, reducing pedal pedal backlash and improving rider efficiency

- Designed for chain case integration, protecting your chain from dirt and debris, and extending drivetrain lifespan

Components & Technology:

- Square Taper JIS interface offers a proven, reliable connection with JIS-compatible crank arms

- Compatible with cranksets requiring a 68mm shell width and 1.37-inch diameter shell, ensuring versatility across a variety of bike models

- Crankarm fixing bolts sold separately, allowing customization based on your specific setup

Style & Use Case:

Ideal for touring bikes, commuter bikes, and vintage-style bicycles that utilize chain case systems, the Shimano BB-UN300-K combines classic styling with modern engineering. Its sleek black finish complements any bike design, providing both aesthetic appeal and technical performance.

Innovative & Differentiating Features:

- Hollow spindle design reduces weight while maintaining stiffness for optimized pedaling dynamics

- Compatibility with chain case installations helps protect your drivetrain from the elements, reducing maintenance and increasing durability

Upgrade your bike's performance with the Shimano BB-UN300-K Bottom Bracket - the perfect choice for riders seeking reliable, lightweight, and smooth-spinning bottom brackets for chain case-equipped bicycles. Enhance your ride today with this trusted component from Shimano's renowned lineup.

  • High-quality, SEO-friendly product bullets for the Shimano BB-UN300-K Bottom Bracket:
  • Optimized for chain case compatibility, this Shimano BB-UN300-K bottom bracket enhances drivetrain protection and overall bike longevity, making it ideal for commuter and touring bikes.
  • Designed with a durable hollow spindle and precision-engineered components, it offers smooth power transfer and reliable performance across diverse riding conditions.
  • Fits standard JIS square-taper cranksets with a 68mm shell width and 117.5mm spindle length, ensuring broad compatibility with a wide range of bicycle frames and cranksets.
  • Featuring a robust English shell interface and high-quality materials, this bottom bracket provides easy installation and long-lasting durability for daily riding and urban commuting.
  • With its sleek black finish and advanced engineering, the Shimano BB-UN300-K combines style with functionality, making it a versatile choice for riders seeking dependable performance and enhanced bike efficiency.
Bottom Bracket Shell I.D.1.37
BB/Frame InterfaceEnglish
BB Shell Width (mm)68
Spindle Interface TypeSquare Taper JIS
Spindle Length117.5
Defined ColorBlack
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Over the years we have served millions of satisfied customers and continue to serve many of them today. With your feedback, we are confident we can take this lifelong journey together and build a friendship that goes beyond parts and accessories.

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Ben Berman Founder & CEO of 365 Cycles


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