RA — Reach Adjust
RA — Reach Adjust
Your geometry, your rules. Fine-tune your bike's reach on the trail, not in the factory.
What Is Reach Adjust?
Reach is the single most important number in mountain bike geometry. RA lets you change it without buying a new frame.
Reach is the horizontal distance from the bottom bracket center to the top of the head tube. It determines how stretched or compact you feel on the bike, and it affects everything: climbing traction, descending stability, cornering agility, and overall confidence.
Most riders accept whatever reach their frame size gives them. But bodies are different. Arms, torsos, and riding styles vary enormously. A change of just 10mm can transform how a bike handles—making it feel like a completely different machine.
DIRTLAB's RA (Reach Adjust) system gives you that power. Through an adjustable headset cup design, you can shift your head tube position forward or backward, effectively lengthening or shortening the reach. No new frame. No stem swap. Just geometry that adapts to you.
Longer Reach
Shifts weight forward. More stability at speed, better descending confidence, calmer on rough terrain. Ideal for aggressive trail and enduro riding.
Shorter Reach
Shifts weight rearward. Quicker steering, easier manuals, more nimble in tight singletrack. Ideal for technical climbing and playful trail riding.
Dial It In
Between-size riders, riders transitioning stem lengths, or anyone who wants to experiment with fit—RA gives you a range to find exactly what works.
How Reach Adjust Works
An offset headset cup system that shifts the steering axis position within the head tube.
Simplified illustration: offset headset cups shift the steering axis relative to the frame, changing effective reach.
Offset Headset Cups
The RA system uses precision-machined headset cups with a built-in offset. By rotating or swapping these cups, the bearing centerline moves relative to the head tube bore, pushing the fork (and front axle) forward or pulling it back.
Head Tube Interface
DIRTLAB frames with RA use a proprietary head tube interface designed for the offset cups. The system maintains full bearing engagement and structural integrity across the entire adjustment range.
Cascading Effect
Shifting the head tube position doesn't just change reach. It also subtly affects trail, wheelbase, and front-center distance—all of which contribute to how the bike steers and handles at speed.
Which Bikes Have RA
Reach Adjust is built into every DIRTLAB frame that uses our advanced geometry platform.
Paratu CP
Our flagship full-suspension carbon frame. RA is integrated into the head tube design, letting you fine-tune reach across the full adjustment range.
RA EquippedIuhu CP
The Iuhu carbon platform shares the same RA-compatible head tube system. Same adjustability, different travel and geometry targets.
RA EquippedIuhu HL
Even our hardtail platform benefits from RA. Tune your reach for XC efficiency or trail playfulness—one frame, multiple personalities.
RA EquippedSetup Guide
Adjusting your RA system is straightforward and can be done trailside with basic tools.
Loosen Headset
Remove the stem bolts and top cap. Carefully slide the stem and spacers off the steerer tube. Remove the fork and headset bearings, keeping everything clean and organized.
Clean all surfaces before reassemblySwap or Rotate Cups
Depending on the RA generation, either rotate the offset cups to a new position or swap to a different offset cup set. Ensure the cups are fully seated and aligned with the head tube bore.
Check orientation markings on cupsReassemble & Torque
Reinstall bearings, fork, spacers, and stem. Set headset preload with the top cap, then tighten stem bolts to the specified torque value. Check for smooth steering rotation with no play.
Always use a torque wrench| Tools Required | Allen key set (model-specific sizes), torque wrench |
| Time Required | Approximately 15–20 minutes |
| Adjustment Range | Approximately 10–15mm total (model-dependent) |
| Stem Torque | Refer to values printed on your stem (typically 4–6 Nm for carbon steerers) |
| Top Cap Preload | Refer to owner's manual (just enough to eliminate play) |
| Re-check After | First ride — verify no play has developed |
RA + G-Volve: The Full Picture
Reach Adjust is one half of DIRTLAB's geometry customization story. The other half is G-Volve.
Find Your Fit
Not sure which size or reach setting is right for you? Our S-Volve sizing system will match your body and riding style to the perfect setup.