35mm Direct Mount RSX Mountain Bike Stem - Adjustable 45-50mm

In this review of the RSX Direct Mount stem the bottom line is clear: this 35mm version is for riders who run a dual crown fork and need a stiff, light, adjustable stem that clamps a 35mm handlebar securely. The reviewer found the stem's precision CNC 6061 alloy construction delivers reassuring rigidity on rough trails, while the split two-piece design and direct mount format keep fitment simple. For downhill and aggressive off-road use the single biggest reason to buy is the combination of a stout 35mm clamp and an adjustable extension that lets riders choose between 45mm and 50mm reach.

Key Features

• 35mm clamp: The larger 35mm clamp increases lateral stiffness and improves handlebar security under heavy load.
• Direct mount design: Made specifically to attach to dual crown forks for a clean, strong interface suited to downhill rigs.
• 6061 aerospace alloy: CNC machining from 6061 alloy keeps the stem lightweight while maintaining structural support for aggressive riding.
• Adjustable extension: Built-in adjustment gives both 45mm and 50mm extension options to fine tune reach and handling.
• Split two-piece construction: The two-piece split design makes installation and alignment easier on dual crown setups compared with one-piece units.
• Color choices: Multiple color options let riders match the stem to their bike aesthetic without compromising performance.

Who It's For

The RSX 35mm direct mount stem is aimed at riders running dual crown forks on downhill, freeride, or heavy duty enduro bikes who want a stiffer cockpit and the option to tune reach. Riders who prioritize clamp strength and low weight will appreciate the 35mm interface and the 6061 CNC construction.

Not every rider needs a direct mount stem: commuters, casual trail riders, or those with single crown forks should look for a standard non direct mount stem and the 31.8mm clamp version if they require a smaller diameter bar option.

Pros & Cons

Pros

• Solid clamp strength from the 35mm interface gives confident steering under load.
• Adjustable 45mm and 50mm extension provides useful reach tuning without swapping parts.
• Precision CNC 6061 construction balances low weight with necessary rigidity.
• Split two-piece layout simplifies installation on dual crown forks.

Cons

• Only available in the 35mm clamp size for this version, so it will not fit 31.8mm bars.
• Direct mount fitment means it is not compatible with single crown forks without the correct adapter or hardware.

Specifications

Our Verdict

The RSX 35mm direct mount stem is a practical upgrade for downhill and aggressive off-road riders who need a stiffer, secure clamp and simple reach adjustment. Its CNC 6061 build and split design make installation and performance reliable, and the adjustable extension adds real tuning value, so it represents solid value for riders with compatible dual crown forks.

Frequently Asked Questions

Will this fit a 31.8mm handlebar?
No, this specific RSX variation is the 35mm clamp version and will not fit 31.8mm bars; check the correct clamp size before purchasing.

Can I use it on a single crown fork?
It is designed for direct mount dual crown forks; single crown forks typically require a different stem or an appropriate adapter.

What adjustment ranges are available?
The stem offers adjustable extension lengths of 45mm and 50mm and corresponding 20mm and 30mm rise positions.