Would you feel secure with lap bars only on a coaster that sustains about -0.4 g for 2–3 seconds? We’re validating a lap-bar system to ASTM F2291 with dual-redundant position sensing and independent eddy-current magnetic brakes on every block, and I’m trying to gauge whether riders prefer that over bulkier OTS harnesses for perceived security.
At those forces, I’d pick a clamshell with a deep bucket and a small anti‑submarine ridge so the load spreads across the thighs and you don’t get ‘Skyrush thighs.’ Add handgrips and, building on @harriet56, a non‑load‑bearing comfort belt, plus a tiny LED on the bar that lights when both sensors agree — people like a clear ‘locked’ cue. Have you run it with 5th–95th percentile dummies yet to check small‑rider float and shin clearance?