






MNZ rule: Front and rear tyres fitted must conform to the tyre importers specifications for the homologated rim sizes for that model.
As this comment unintentionally brings a slur to my name, as I ran the Heidenau K73 Dot 'super rain' tyres for a round of Vic Prolites last year before the rule was changed, let me air my understanding.
My information comes directly from the Heidenau factory Tech spec's...
Both the 120/70-17" and the 160/60-17" K73 come in a silica rich soft compound 'race rubber', 'RSC', and a non silica intermediate compound rubber, 'RKM'.
They have a recommended rim size of 3.50 front, and 4.50 rear.
But are suitable for rim sizes 2.75 - 3.75 Front
and 3.75 - 5.00 rear.
So to my understanding, from a size point of view, the 3"/4" rim combination of the hyosung and others is within the specifications for this model tyre.
Am I miss understanding the rule?
One could also argue that the Heidenau intermediate compound K73 is not a 'specialist Intermediate wet weather tyre', as it's not listed in the racing section of the Heidenau website. But is just classified as a 'road' tyre, good for wet conditions.
But given that Heidenau continued with the 'super rain' wording on the sidewall of this tyre, it could be a case of pushing the preverbal uphill to get that understanding through!
I could not find anywhere on the MNZ website, about what the clarification of a 'Wet' was.
It used to be understood as a non DoT wet tread tyre. But now with that rule changed to include Dot 'wets', How do we know What a 'Wet' is?
Is it wording on the tyre?
Compound of the rubber?
Look of the Tread ?
Whats the criteria?





The information I have regarding these tyres came direct from the Distributor for this brand, who sells this brand of tyres into the race scene here and in Australia.
He tells me these tyres are a specialist wet weather race tyre for intermediate use, and although "DOT" marked are intended as a RACE tyre
From what you say, I may be mis-informed regarding the rim sizing though - where did you say your info comes from, as it appears to differ from what I've been told, and isnt what I have in the latest Heideau catalogue
The rules are there to ensure, as far as practicable, the mythical "level playing field" for all Competitors in this Class and to keep wallet racers out of contention
I'm not saying a Phaarkin word.....![]()
"That's rooted!! What's next??"
Im sorry....had to speak on this one
FACT the tyre has DOT approval..which is all that some see
Intention as a race tyre is in the same "grey area" bracket as interpretation and assumption (and we all know about the last one biting us)
And one persons interpretation of the word "practical" against another will probebly stretch the realms of vagueness. In fact i would like to see a discussion about practicality with some of racings more vocal and colorfull types
And a someone said in a earlier post... if its not in the ruling you cant touch it... This is automatically interpreted/assumed/intended as if it "does say you cant- you can! by the other side.
The rulings are fundamentally correct... just not detailed enough or specific enough.
This would take time and consultation with various parties.... but could make it all very black & white.
Sorry...just had too
I would just like to see a list of "cans" v "cant,s simple.

Yerr,Its always been my biggest bone of contention surrounding "Production" racing rules,That if you have a list of cans and cants it leaves a whole raft of maybes,However by stating in the rules "if its not mentioned,You cant touch it"Clears that up,Doesnt it ???
I mean,You have to be reasonably stupid to not understand that,Either that or ignorant!!
Its easy enough to email the roadrace commission chairman at the correct email address if your unsure of any issues you confront,Kiwibiker is not that address!Anybody posting that sort of request on this site is most probably,As I stated last night,Fishing for the right answer to justify their actions!!!
Remember,Ignorance or failing to ask the right people is not an excuse at the track!!
Ok, it seems it depends where you look on the Heidenau website.
I see there is a new 'English worded' race tyre catalogue there now where they do group the intermediate K73 in with their race tyres. Yet on their main site they still have the intermediate K73 grouped in with their road tyres only.
Will get the importer to suggest they sort it out.
I was quoting from last years fuller 'Retailers technical data sheets' that Heidenau produced in German only. (I just read it for the pictures and numbers)
I'm in full support of Racey Rider. A good person / rider who made an effort to support a class and play by the rules. For this he's rewarded by MNZ changing the rules in the middle of a championship without consultation with riders. He now has a set of tyres only good for growing geraniums in. Is that fair?
Don't have MNZ rules about changing rules? Aren't rule changes an annual affair, after consultation/feedback? And they can't use the excuse it's a safety matter. Taking away the RIGHT of the rider fit race wet tyres for wet racing (and it really does piss down at Manfeild and Hampton Downs! (often!) is surely taking safety the wrong direction. It's only a few years ago Alan Cressey gave legal advice to MNZ that they cannot prevent Streetstock riders the opportunity to fit wets as every other class (and every other motorsport on sealed surfaces) is allowed them.
Isn't this case of MNZ breaking rule making rules themselves?





There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks