CST Big Boat Tire – 20 × 4.0 | Wire Bead

The CST Big Boat 20 × 4.0 is a large-volume, durable fat tire designed to provide stability, comfort, and dependable grip for fat bikes and compact e-bikes.

Its round profile and low-rise, micro-knurled tread sections create a smooth, predictable ride on pavement and hardpack, while wide siping and multiple working edges add traction without significantly increasing rolling resistance. This balanced tread design makes the Big Boat well suited for urban riding, bike paths, boardwalks, and mixed-use surfaces.

The generous 4.0" width increases air volume for improved comfort and control, especially on heavier bikes or when carrying cargo. A wire bead construction prioritizes durability and value, making this a solid replacement or upgrade option for everyday riding.

Key Features

• Large-volume 20 × 4.0 fat tire for stability and comfort

• Low-profile tread balances grip and rolling efficiency

• Micro-knurled tread with siping for predictable traction

• Durable construction suited for daily use

• Ideal for fat bikes and compact e-bikes

Technical Details

• Size: 20 × 4.0

• ISO: 406

• Bead: Wire

• Style: Standard Clincher

• TPI: 60

• Max PSI: 30

• Weight: 941 g

• Tread Style: Smooth / Low-Profile

• Sidewall: Black / Skinwall

The CST Big Boat is a practical, comfort-focused fat tire choice for riders looking for durability, stability, and smooth performance across everyday riding surfaces.