Siecross Office Chair – Acme Furniture
Our Siecross Office Chair transforms your workspace with professional-grade ergonomics and contemporary style. Engineered for professionals who spend extended hours at their desk, this chair delivers exceptional lumbar support through our patented FlexSpine™ technology.
The breathable mesh backrest promotes airflow during long work sessions, while the multi-position armrests adjust to your exact preferences. We've designed the Siecross to support healthy posture naturally, reducing fatigue and discomfort throughout your workday.
Built on a reinforced steel frame with premium components, the Siecross carries our comprehensive 20-year structural warranty. Whether you're managing video calls, deep-focus work, or creative projects, this chair adapts to how you work best.
Ergonomic features & specifications
Materials & Construction
We’ve built the Siecross on a foundation of commercial-grade materials engineered for daily use. The reinforced steel frame features welded joints and powder-coat finish that resists scratches and wear.
The seat cushion uses high-density memory foam that maintains its shape through years of use, covered in premium fabric with stain-resistant treatment. Our breathable mesh back incorporates nylon filaments woven in a tension pattern that provides support while allowing continuous airflow. The pneumatic cylinder meets BIFMA safety standards for smooth, reliable height adjustment.
Ergonomic Adjustment Guide
Customizing Your Siecross
Achieving optimal comfort starts with proper adjustment. Begin by setting the seat height so your feet rest flat on the floor with thighs parallel to the ground. This typically places the seat between 17.5 and 21.5 inches from the floor.
Next, position the lumbar support to align with the natural curve of your lower back, about 20 inches from the seat base for most users. The FlexSpine™ system allows both height and depth adjustment to match your unique spine contour.
Assembly & Care Instructions
Your Siecross arrives partially assembled with all necessary tools included. Most customers complete setup in 20 to 25 minutes following our illustrated guide. The base, casters, and gas cylinder connect without tools, while the backrest and armrests require only the included hex key.
For ongoing care, vacuum the mesh back weekly to prevent dust buildup. Spot-clean the seat cushion with mild soap and water, blotting rather than rubbing. The casters should be inspected monthly and cleared of any debris.
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Siecross Office Chair: Common Questions
The Siecross supports up to 300 pounds safely. Our reinforced steel frame and Class 4 pneumatic cylinder are engineered to handle this capacity while maintaining smooth adjustment and stability.
The seat cushion uses high-density memory foam that maintains its supportive properties under regular use within this weight range. All load-bearing components are tested to exceed industry safety standards.
Our comprehensive 20-year warranty covers the steel frame, base, and all structural components against manufacturing defects and normal wear. The pneumatic cylinder and tilt mechanism carry a 5-year warranty.
Upholstery and mesh fabric are covered for 3 years against defects in materials or workmanship. Casters and armrest pads, considered wear items, have a 1-year warranty. We provide straightforward replacement for any covered component that fails during the warranty period.
Yes, the Siecross adjusts comfortably for users between 5'2" and 6'4". The pneumatic height adjustment offers a range from 17.5 to 21.5 inches from floor to seat.
The lumbar support adjusts vertically and horizontally to align with different spine lengths and curves. Armrests move through a wide range to accommodate varying torso heights and desk setups. For optimal ergonomics, we recommend pairing the chair with a desk height appropriate for your stature.
The breathable mesh back is specifically designed for extended sitting sessions. Unlike solid backs that trap heat, our tension-woven mesh promotes continuous airflow to keep you comfortable during 8-plus-hour workdays.
The mesh provides firm support that flexes with your movements while maintaining the ergonomic contour. Most users find the combination of supportive mesh back and memory foam seat ideal for all-day comfort without the stuffiness of fully padded chairs.
Our dual-wheel casters are engineered for multi-surface performance. They roll smoothly on hardwood, laminate, tile, and low-pile carpet without scratching or leaving marks.
The soft polyurethane wheel material protects hard floors while providing enough grip to prevent sliding. For high-pile carpet, the casters distribute weight effectively to avoid sinking. A chair mat is optional but not required for floor protection with normal use.
Most customers complete assembly in 20 to 25 minutes using only the included hex key. The process involves five main steps: attaching casters to the base, inserting the pneumatic cylinder, mounting the seat mechanism, connecting the backrest, and installing armrests.
Our color-coded instruction manual shows each step clearly with photos. No prior furniture assembly experience is necessary. The base and cylinder connect without any tools, making the initial setup especially straightforward.
Yes, all primary adjustments on the Siecross operate while seated. The pneumatic height lever, tilt tension knob, and tilt lock engage easily from the sitting position.
The lumbar support adjusts via controls on both sides of the backrest that you can reach without standing. Armrest adjustments use simple buttons and levers accessible while seated. This design lets you fine-tune your position throughout the day without interrupting your workflow.