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The Thomson X4 Stem utilizes a more traditional split clamp design to save weight without sacrificing stability and control. The X4 features a sculpted stem, sleek clamp bolts, and is made with 7000-series aluminum alloy to ensure torsional stiffness and precise steering. The X4 Stem comes with a 3-year warranty from the manufacturer. The stem is available in Black or Silver with a zero (90) or 10-degree (100) rise.

  • 7000-series aluminum
  • Sculpted stem and sleek clamp bolts
  • Split clamp design
  • 31.8mm clamp diameter

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Here's what others have to say...


Thomson, enough said

  • Familiarity:I've put it through the wringer

I love Thomson products they're well made and in the U.S.


On every mountain bike

  • Familiarity:I've put it through the wringer

This stem ends up on every mountain bike I own. It's brilliant. Stiff and light, doesn't slip.


No surprise here

  • Familiarity:I've put it through the wringer

Excellent as usual from Thomson... All my bikes have Thomson Post and Stem..

Works great for a road bike too!

Works great for a road bike too!

To get my desired drop, I needed a zero rise stem, and Thomson fit the bill. There aren't many zero stems out there.


Solid, expensive for weight

  • Familiarity:I've used it several times

Thomson x4 stem is very solid, great materials, great construction, looks good, and has +/-10 which fit my needs perfectly. my only gripe would be that the stem is a little on the heavy side given the price point. there are many alternatives to the Thomson x4 stem that cost 1/2 the price and accomplish the same task, so you are definitely paying extra for the Thomson brand. most of the time I would be bothered by that, but not as much here, given that this stem definitely delivers on its quality focus and offers the steeper angle (-10) that many others don't.

Solid, expensive for weight
X4 on the Cross.

X4 on the Cross.

Dressed up with the blue face kit. I just had to have it.



  • Familiarity:I've put it through the wringer

Thomson, made in the good ol' US of A. Over the years I've had everything from a 50mm up to a 120mm on my rides. They are so good, I just can't seem to quit them.