Backrest Upright Adjustment Knob

BACKREST UPRIGHT ADJUSTMENT KNOB Replacement knob • 30-second installation • No tools required WHAT THIS KNOB DOES The backrest upright adjustment knob controls the vertical height position of your backrest. Loosen the knob, slide your backrest up or down the vertical bar to position it exactly where your lower back needs support, then tighten the knob to lock it in place. This lets you customize the lumbar support zone to match your specific spine height and body proportions. WHY VERTICAL POSITIONING MATTERS: Everyone's lumbar curve sits at a different height. A 5'4" engineer and a 6'2" engineer need their backrest positioned completely differently to hit the right support zone. Without this knob, you can't adjust the backrest height—and without proper lumbar positioning, ZenWave™ technology can't do its job. You're stuck with whatever random height the backrest happens to be at, which defeats the entire purpose of an ergonomic chair. WHY YOU MIGHT NEED A REPLACEMENT: Lost or misplaced during chair transport, venue moves, or tour packing Stripped threads from over-tightening or cross-threading over years of adjustments Physical damage from drops, impacts, or getting caught in road cases Worn grip making it difficult to loosen/tighten properly Multiple users sharing one chair and needing quick height changes Spare inventory for venues, studios, or touring rigs with multiple chairs This is one of those parts you don't think about until you need it—and when you need it, you need it immediately. A missing knob means you can't position your backrest, which means you can't work comfortably, which means your chair becomes basically useless for professional use. EASIEST REPLACEMENT PART WE SELL INSTALLATION STEPS: 1 Unscrew old knob Turn counterclockwise (lefty-loosey) until it comes off the threaded rod 2 Screw on new knob Thread it clockwise (righty-tighty) until snug—hand-tight only, don't force it That's it. No tools. No instructions. No video needed. If you can open a water bottle, you can replace this knob. IMPORTANT: Don't Over-Tighten This knob only needs to be hand-tight to hold your backrest in position. Over-tightening can strip the threads or crack the knob. Tighten it until you feel resistance, then give it about a quarter-turn more. That's it. The backrest won't slip during normal use as long as it's reasonably snug. SPECIFICATIONS Function: Backrest Height Lock Material: High-Grade Polymer Color: Midnight Black Thread Size: Standard Stealth/ErgoLab Installation Time: 30 Seconds COMPATIBILITY: Standard replacement knob for all Stealth and ErgoLab chair models with adjustable backrest height mechanisms. This is the genuine OEM part—not a generic substitute that might not fit properly, strip your threads, or fail under normal use. WHY WE STOCK PARTS THIS SMALL Here's the reality: a missing $26 knob can make a $750 chair unusable for professional work. Without it, you can't adjust your backrest height. You can't position the lumbar support where your spine needs it. You're locked into whatever random height the backrest happens to be at—and if that doesn't match your body, you're working in pain. Most companies would tell you to buy a whole new chair. We'd rather sell you a $26 knob and keep your chair running for another decade. This is especially critical for touring professionals and multi-user environments. Knobs get lost during load-in, knocked off during transport, or damaged in the chaos of festival setups. Having a spare in your road case means you're never down a chair mid-tour. For venues and studios with multiple engineers using the same chair, having spares means everyone can quickly adjust the backrest to their height without fighting stripped threads or missing parts. This knob represents everything we believe about professional equipment: it should be built to last, easy to maintain, and impossible to make obsolete. As long as we're making Stealth Chairs, we'll stock every part you need to keep them running perfectly. PRO TIP: TOURING & MULTI-USER ENVIRONMENTS Keep spare knobs in your road case, gear bag, or venue spare parts drawer. When you're setting up for a show and discover a missing knob, you don't have time to wait for shipping. Spend $26 now to avoid a $750 problem later. For studios and venues with multiple users: consider keeping 2-3 spares on hand. When different engineers need different backrest heights throughout the day, having extras means you can swap a damaged knob instantly instead of everyone fighting with a stripped thread or struggling with a worn grip. Small investment, massive convenience. OTHER REPLACEMENT PARTS Complete your spare parts inventory with these other common replacements: Replacement Levers Height and tilt adjustment levers for complete control Suspension Bushings Restore smooth pivoting and ZenWave™ motion TourMax Casters Heavy-duty wheels for tour and venue environments