3.8 vs 4.5 Fat E-Bike Tires – Pros and Cons

E-bikes must be properly matched with appropriate tires for your use case. Fat tire E-bikes are bikes designed to ride on snow, sand, and other soft terrains. They have wider tires, usually 4-5 inches wide, that provide more stability and traction than regular mountain bikes. The 3.8″ and 4.5″ are the exact diameter of the tire’s sidewalls.

But what are the differences between these two types of fat tires? Well, in this article, we will compare these two brands of fat E-bike tires, their pros and cons, and their performance in various terrains.

Fat tire ebike
Credit: Flickr

Key Differences Between 3.8 and 4.5-inch Fat E-Bike Tires

Here are some key differences between the 3.8 and 4.5-inch fat E-bike tires.

1. Size

One of the most significant differences between these two sizes is their diameters. The 3.8-inch tire is about 2 inches narrower than the 4.5-inch tire. People who want fat tires for riding purposes should choose the larger size for their bikes. But there are two exceptions to that rule. If you plan to ride on ice and snow, a 3.8-inch tire may work better than the 4.5-inch one on your E-bike because of its low rolling resistance qualities. On the other hand, 4.5-inch tires are preferred by many riders because they are more durable.

2. Weight

Another significant difference between these two tire sizes is their weights. The 4.5-inch tire weighs 5 lbs or 2 kg, while the 3.8-inch one only weighs 2 lbs or 1 kg. The latter is much lighter than the former and is ideal for long journeys.

3. Speed

The larger size of the 4.5-inch tire enables it to roll faster than the 3.8-inch one, at least on smooth surfaces. The 4.5-inch tire bounces more easily over bumps and holes, while the 3.8-inch one struggles. So, if you plan to use it on bumpy roads, a fat E-bike with 4.5-inch wheels is better than one with 3.8 inches wheels.

4. Inflation

The 4.5-inch tires require higher inflation pressure than the 3.8 inches ones, which makes them less comfortable to ride on. Since they are more sensitive to pressure, they are more prone to punctures too. So, if you plan to ride on rough terrains, you better pick the 3.8-inch tire because it will be more comfortable and durable than the 4.5-inch one.

5. Weight Distribution

Despite the size, there are barely any differences in weight distribution between the two. The 4.5-inch tire weighs 25% more than the 3.8-inch one, but they are both at the same height from the ground’s surface when mounted on a bike. So, depending on your individual needs, you can get away with either one.

Pros of 3.8-inch Fat Bike Tires

  • Increased Maneuverability: The lighter weight of 3.8-inch tires makes the bike more maneuverable, allowing riders to easily navigate tight turns and obstacles.
  • Ideal for Hardpack Terrain:8-inch fat bike tires are ideal for riding on hardpack terrains such as rocky trails, packed snow, and ice. The narrower tire width provides better traction and stability on hard surfaces, making it easier for riders to maintain control.
  • Lower Price Point:3.8-inch fat bike tires are generally more affordable than 4.5-inch tires, making them a great option for budget-conscious riders.
  • Lightweight: The 3.8-inch tire is much lighter and more durable than the 4.5-inch one, making it an ideal choice for riders who want to travel long distances on their fat bikes easily.
  • Less Rolling Resistance:With the larger diameter of 4.5-inch tires, riders struggle to maintain a good speed on rough terrains such as rocky trails and packed snow, where it is difficult for ball bearings to rotate smoothly. Therefore, the 3.8-inch tires provide better traction and stability during hard rides in such scenarios.

Cons of 3.8-inch Fat Bike Tires

  • Need a big-size hub:The 3.8-inch tires require a bigger hub for proper fitting, which can be inconvenient for many riders.
  • Uneven Wear: With a smaller and lighter weight, the 3.8-inch fat bike tires are not durable enough to handle rough terrains like rocky trails and packed snow. Therefore, they produce more uneven wear than 4.5-inch ones.
  • Poor Rolling Capacity: Although the 3.8-inch tire has a bigger diameter than the 4.5-inch one, it is less efficient in rolling over rough terrains, especially when the rider is carrying a heavy load.
  • Not Ideal for Snow and Ice:If you plan to ride your fat E-bike on snowy or icy terrains, a 3.8-inch tire may not be suitable because of its low traction on these surfaces.

Pros of 4.5-inch Fat Bike Tires

  • Versatility: The 4.5-inch fat E-bike tire is versatile, functioning in all types of terrains and weather conditions, including snow, sand, and gravel trails, making it the perfect choice for most riders who like to go on long journeys in different terrains.
  • Uniform Wear: With a larger diameter, the 4.5-inch tire distributes weight uniformly and produces uniform wear.
  • Better Rolling Capacity: The larger diameter of 4.5-inch fat tires allows them to roll efficiently and are more stable than the 3.8-inch ones on rough terrains such as rocky trails and packed snow. However, they struggle in hardpack terrains like icy trails.
  • Increased Traction:5-inch fat bike tires provide more traction on soft terrains such as snow and sand than 3.8-inch tires. The wider tire width provides a larger surface area for grip, making it easier for riders to maintain control on rough and uneven terrain.
  • Increased Stability:5-inch fat bike tires provide more stability than 3.8-inch tires due to their wider width. The wider tire provides a larger footprint, making it easier for riders to maintain balance on rough and uneven terrain.
  • Increased Comfort: The width of 4.5-inch tires provides more cushioning and shock absorption than 3.8-inch tires. This makes the ride more comfortable for the rider, especially on rough and uneven terrain.

Cons of 4.5-inch Fat Bike Tires

  • Heavy: Compared to 3.8-inch tires, the 4.5-inch fat bike tires tend to be heavier, which makes them less suitable for long journeys.
  • Wider Tire: The wider tire width and diameter of the 4.5-inch fat E-bike tires may cause problems navigating tight turns and obstacles because of the limited space between the narrow pedal spacing and front fork/frame.
  • Higher Price: Due to the larger size of 4.5-inch fat E-bike tires, they are priced slightly higher than 3.8-inch tires.
  • Slower Rolling Speed: The wider tire width of 4.5-inch tires results in a slower rolling speed than 3.8-inch tires. The increased rolling resistance also makes it harder for riders to maintain speed on flat terrain.
  • More Difficult to Navigate Tight Turns: The heavier weight of 4.5-inch tires makes the bike less maneuverable, making it more difficult for riders to navigate tight turns and obstacles.


While the size and weight of fat bike tires are important factors to consider when selecting the right tires for your E-bike, there is still a great disparity between 3.8-inch and 4.5-inch tires. The choice between 3.8-inch and 4.5-inch fat bike tires will ultimately come down to personal preference and the type of riding you plan on doing. 3.8-inch tires are lighter and provide faster rolling speed but have less traction and stability, while 4.5-inch tires are more stable and provide more traction and comfort but are heavier and have slower rolling speeds.

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