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31.8mm MTB Carbon

$201.95

You have two mountain bike carbon fiber handlebars to choose from: a classic flat center rise bar and a 15mm riser bar in carbon for strength and all day ride comfort. They’re the perfect bars for your X4 stem.

Pair it with a Thomson stem for a balanced, confidence-inspiring cockpit.

Description

We’ve created two carbon fiber bars for the Mountain Bike enthusiast: a flat bar with an off center clamp area allowing a flat riding position and reversible for a 5mm drop for 29 inch bikes. They also have 8° of backsweep for comfort and 730mm (29′) in width for plenty of leverage.

The second model is 750mm wide and offers 15mm of rise together with a 8° backsweep and 5° upsweep. It’s built for strength with enough flex built in for all day comfort. It’s strong enough for all mountain/trail riding and light enough for racing.

The bars are made with three different fiber types with different tensile strength and tensile modulus, including high strength carbon fibers. This helps to allocate stiffness and flex where needed.

The bars are molded with an EPS mandrel inside to avoid wrinkles inside the layup during molding. Most other bars are molded over inflated nylon bladders.

All carbon fiber material is produced by Toray and uses tailor made nano Epoxy Resin for very high impact resistance. Toray is the main supplier of carbon fiber to Boeing and Airbus.

1.5K woven impact ends help prevent damage to unidirectional fibers from shortening the bar or impact with the ground. With a light weight and precision tolerance clamp sections, it’s the best bar for your Thomson X4 stem. It’s also certified to EN, tested to DIN+.

See our warranty information here.

Trail-Ready Control

Optimized Feel for Every Riding Style

Engineered from premium carbon fiber, the 31.8 mm MTB Carbon Handlebar is tuned for precise response across climbs and singletrack. The flat bar, for cross country use, measures 730 mm wide with 8° backsweep, while the riser bar, for trail and all-mountain use, adds 15 mm rise, 750 mm width, and 5° upsweep. We deliver two segments and two use cases to cater to both audiences.

Designed for Comfort

Less Fatigue on Long Trail Days

This carbon mtb handlebar flexes where you need comfort while keeping stiffness for precise steering. Multiple carbon fiber types balance power and compliance, with tuned vertical compliance to reduce hand fatigue and arm pump from trail vibration.

close up image of carbon handlebar on a track

Tuned Construction

Advanced Carbon Layup Technology

Each carbon bar is molded with an EPS mandrel for smoother internal layups and lasting consistency. Using Toray carbon fiber and nano epoxy resin, Thomson’s bars offer impressive impact resistance. 1.5K woven ends protect fibers if shortened or struck.

birds-eye view image of carbon handlebar on wood surface

Confidence in Design

Made for Trail and All-Mountain Use

Designed in Georgia and molded in Taiwan, the 31.8 mm carbon handlebar meets EN and DIN+ standards. It’s strong enough for trail and all-mountain riding yet light for racing. Precision stem clamp tolerances pair perfectly with the Thomson X4 for balanced ride quality, vibration damping, and control.

Details That Matter

Simple, Clean, and Reliable Setup

The 31.8 mm clamp diameter fits most mtb bars and stems. Cut marks make trimming simple. Use a 32 tpi saw and torque wrench when installing brake levers. Apply carbon paste if needed.

very close up image of thomson carbon handlebar on wood surface

A Bar You’ll Want on Every Ride

This is the mountain bike handlebar you’ll reach for when control, comfort, and reliability matter most. Designed for trail and all-mountain riders who expect premium carbon fiber performance backed by meticulous engineering.

Build Your Dream Bike

Seatposts

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Stems

Pair your bar with the right stem length and angle for control and comfort.

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Small Parts & Hardware

Find spare bolts, clamps, and more to keep your setup dialed.

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FAQ

Are the Thomson MTB Carbon Bars made in Macon?

Can I cut the 31.8 mm MTB Carbon Handlebar?

Is the bar compatible with all stems?

Can I use these for downhill or dirt jumping?

What if I crash?

How long is the warranty?

How does the Thomson Carbon Handlebar compare to aluminum bars?

Is the Thomson Carbon Handlebar compatible with other stems?

About Bike Thomson

Thomson started in aerospace, and we’ve kept that same focus on precision since the beginning. Based in Macon, Georgia, we machine and assemble every component with care, from stems and seatposts to carbon handlebars mtb riders trust. Every product reflects our commitment to craftsmanship, performance, and reliability. Ride after ride, year after year, our parts just work.