Helmet, plus harness, means that in a sudden stop the only thing moving forward is the helmet, unfortunately still containing a head ... thus neck injury as helmet moves forward, pulling neck as it does so. Driver is fine, except for broken neck. Minor detail.
Theory is that a standard lap/sash belt allows enough body movement, that head/neck/shoulders are able to move sufficiently to allow the neck to withstand the forces imposed by the helmet's movement forward.
One thing that is also overlooked is the weight of a helmet - unless you are spending pretty big $$, the helmet will weigh a fair bit, and this weight/mass adds to the problem when the helmet is unrestrained.
The sooner HANS-type devices are made mandatory (for speed events), the better. Easy for me to say, I have mine, but the reason I got mine was because I could see (a) the writing on the wall, and (b) the sense of them. At that point there is no reason to hold off - my big accident may happen before they are made mandatory, and my kids deserve to have me around a bit longer - if HANS will help me achieve that outcome, it is worth paying up now.
Cost is not an issue - motor sport is expensive. If you can't afford it, stick to non-speed events (eg motorkanas) until you can.
This is just the latest thread to address this issue. If there are any doubters, do a search and watch some of the videos.
Ben, if you are have second thoughts, I converted my old harness to a six point for around $130, adding the crutch straps.
