Features /

4 Series takes its cue from light, fast XC bikes. Dialed geometry, race-inspired tech, and unbeatable ride feel make this an excellent platform for trail riders on a budget.

Upgrades from 3900 Disc

  • Alpha Gold Aluminum frame
  • Shimano 9-speed drivetrain
  • Shimano Acera crank
  • Shimano M395 hydraulic disc brakes

Alpha Gold Aluminum

Trek’s high-performance aluminum, with manipulated tube shapes to balance strength and weight saving.

26" wheels

The original 26" mountain bike wheel size is now the smallest of three available diameters. It’s the most flickable, most playful wheel size.

Suspension lockout

Lock out the suspension fork for efficient riding on smooth terrain.

Extended size range

A wider range of sizes than the industry standard provides more option for everyone, from tallest to shortest and all those in between. Because everyone deserves a great ride.

Hydraulic disc brakes

Ultimate control and stopping power in all conditions, including wet and muddy.

Oversize stem and handlebar

31.8mm oversize clamp diameter increases stiffness for more confident, precise handling.

Internal derailleur routing

Route your derailleur cables through the frame to keep your bike running smooth and clean.

Suspension fork

Shock-absorbing fork allows the front wheel to travel up and down over bumps while the handlebars stay steady, for a comfortable, controlled ride.

Rack & fender mounts

Built-in mounts make it easy to add racks and fenders for added versatility.