Ray, I am stating "only the circumference zipper of a two piece race suit needs to be metal" to be an official ECTA answer.
As always, it's Keith's or the board's prerogative to change that(should anyone like to contact them directly). It's also an inspector's prerogative to not sign off on anything(from bike to gear) that he is not comfortable in doing so(such as a zipper that he doesn't feel is up to standard integrity wise - IE: broken or missing teeth, cheaply made, bad thread sewn in, dry-rot material, etc. etc.), be it metal or Y2K either one. I've certainly seen metal ones signed off on that are in much worse shape then many vinyl ones I've come across. It also any entrants choice to go beyond the tech inspector he is dealing with if they feel there is an interpretation issue.
Ol38y, I've done some BS zipper pull tests here a while back and can tell you that the separation factor is not related to the material(metal or vinyl), but more so in the design, placement, number of the teeth used. There were more metal then "plastic" zippers that I could pull apart(at least of the ones at my disposal). The melting factor (as this is about concrete, not salt) is one to be considered also(and was discussed at length in January of 2004 and again in August of 2004 - including the possible effects of Plastic, Polyester, Nylon, Steel, Brass, Nickel & Aluminum). In a nutshell... the pants to suit connection is considered a long term contact point as when you are length wise on the concrete it could weaken the connection by heat and is the reason for metal at this point(let alone the cracks grabbing the separate pieces and pulling them apart no matter the material). On the other hand, when the body turns 90* to the track it tends to not slide much when any friction is exerted and will instead "pencil roll" the person and alleviate the heat(and tension) build up.
I know this is an interpretation question rather then a rule change question(which is able to be done by any "member" at any time by the way), but other then the legwork that went into it and the last in-depth discussion of this(in a committee meeting with PB, DL, WP, SG, and myself), Debbie and I also have finished resurrecting and assessing the suit(and gear) she was wearing in here slide and roll down the concrete. Which(in just one pertinent area to this conversation), happens to have a the wear "across" the chest(enough to wear a hole through it) and zipper(thankfully she always wears her chest protector), and still shows no an attempt in separating the zipper(which is "plastic" by the way) from itself or the suit .
Is more protection better? Normally yes to some extent.... but is it always feasible for the amount of gear being produced and continually showing the ability to protect those that have tested it in the worst of ways? My bet is 50% or more of the entries at the next meet will not be eligible to run if we would enact a all metal zipper rule today.
I think the key here(like anywhere concerning the components we use for safety or function either one)... it's more about design, integrity and condition then material.
Todd
