Is it legal to not have one? - (rear guard)

[kiwifruit]

Is that what you're yelling in your avatar?

amongst other things, yes

[Steam]

...What does this gobbledegook really mean especially point 3 about the twin or close spaced tyres?

Brough Superior 800cc Straight Four, 1930's. They had twin rear wheels, with the drive train between them.
There is one at the Southward Car Museum near Wellington. Merv, you MUST GO THERE. It's more than you can take in one visit. http://www.southward.org.nz/viewgallery.php?id=4
I can't find a good picture of the twin rear sadly.

[merv]

Gee I've been to Southwards a few times and can't say I've noticed the twin wheels.

It was this bit I was having trouble with:

"that provides continuous protection from a horizontal line tangent to the top of the tyre tread to a line with a slope of 1:3 rising rearward from the tyre’s contact point on the road".

[Steam]

Gee I've been to Southwards a few times and can't say I've noticed the twin wheels.

It's down with the cars on the main floor, unless they've moved it. I'm off there next Saturday, there's an auction of various junk. Most excited! Junk! But this is sorry.

[Mukura]

Gee I've been to Southwards a few times and can't say I've noticed the twin wheels.

It was this bit I was having trouble with:

"that provides continuous protection from a horizontal line tangent to the top of the tyre tread to a line with a slope of 1:3 rising rearward from the tyre’s contact point on the road".

I googled up this PDF with a picture - check out the last page for a diagram regarding the slope and tangent http://docs.google.com...

The thing about this is that not a lot of modern production bikes look like this picture... the thing about nzta is that no one knows anything unless it's in their interest to know. I know from regoing my bike last year, they never even looked out the window at it - I could've told them anything I liked. At that time I also found out it's not a legal requirement to have a frame or engine number - and that you can just 'dream' one up if you like - for your own saftey of course if the vehicle gets pinched then you have paper work on your side (like that helps).

Moral of the story is one we should all already know too well :

A) You have to ride it, look after your own safety
B) Your mate might be following you, think about them
C) You don't have to be a rocket mechanic to have a starting salary of $55k+ and a company car for the biggest gang in NZ - so odds are you probably aren't a rocket mechanic, or any other sort of genius - let alone an expert in technicalities that very few people are even aware of (rear guards) - so if it looks kosher you are probably sweet.
D) Every now and then in life you will meet a know-it-all s.o.b - this is the point where you hit the switch to flip your plate up and ride like the wind son....

Hope this helps, or is at least marginally entertaining. Cheers