Streetstock tyres..

[Tim 39]

I read on the MNZ website that they have taken the saving their own arse approach to this problem. Streetstock bikes now have to run on road legal tyres (expensive ones) even in the dry. Not the best outcome for the 70 or so South Islanders who now all have to buy new tyres at over $300 a set!

[k14]

Well rather than critise their ruling maybe you could suggest a better way to do it?

I read their ruling and totally agree with it. No other way to do it fairly.

[Tim 39]

Well rather than critise their ruling maybe you could suggest a better way to do it?

I think they need to give the riders a period of time to be able to get and fit new tyres. at the moment they don't have anywhere near enough tyres in the country, so theyre going to have a big problem at sportzfotoz cup at levels if only 10 or so people are allowed to ride (biggest event all year for the streetstock riders)

my basic opinion is that if the changes were to be effective immediate, they could have warned the riders so they could order some new tyres in, or given a change over period.

[oyster]

This is a big subject with a long history. Tim has in fact contributed a lot through our collective voices to MNZ, and is not alone in his disappointment that major concerns, including many safety matters, have not been addressed by the MNZ decision. We have appealed for a review of the new rules, on the basis of poor consultation. The board have accepted that and Johnny Hepburn, Board Member, Road, announced testerday that the existing rules are extended for at least two months until a "round the table" meeting between the riders/supporters and MNZ is held. This is scheduled for 1st Sept. I will be attending this meeting and anyone with views on this subject are welcome to post up or PM me on their contributions.
Peter Jones
Junior Road Race Coordinator
Motorcycling Canterbury

[Tim 39]

This is a big subject with a long history. Tim has in fact contributed a lot through our collective voices to MNZ, and is not alone in his disappointment that major concerns, including many safety matters, have not been addressed by the MNZ decision. We have appealed for a review of the new rules, on the basis of poor consultation. The board have accepted that and Johnny Hepburn, Board Member, Road, announced testerday that the existing rules are extended for at least two months until a "round the table" meeting between the riders/supporters and MNZ is held. This is scheduled for 1st Sept. I will be attending this meeting and anyone with views on this subject are welcome to post up or PM me on their contributions.


good to hear, thats the part I felt they were lacking. I felt that they just made the decision on behalf of everyone and said thats the way it is. Now the riders get enough time to sort out their tyres and have some warning of what will be happening.

[Tim 39]

This option is arguable, but I believe long term it would be cheaper to make the use of wets both safer and cheaper. with the new rules a streetstock rider will spend approximately $900 on tyres. A set of rims and some second hand RS125 wets would cost less than that, and wets are better in the wet and slicks are better in the dry. You're also teaching how to make decisions where it doesnt matter so much, rather than waiting to go 125 or SV to learn to make those calls.
negatives:
the "old" slick rule is hard to police, and so would the "old wets" rule. The expense (arguably) is higher

[MOTOXXX]

get yourself a set of TT900 tyres if you can find them. They are the shit.

you can ride em just as hard in the rain as in the dry. there is nothing better for the 150s

[Tim 39]

get yourself a set of TT900 tyres if you can find them. They are the shit.

you can ride em just as hard in the rain as in the dry. there is nothing better for the 150s

I rode on tt900's at levels, and got the back stepping out under power on an FXR!!! Bridgestone battlax make some tires that fit and work about as well

[Billy]

While I have to admit to not having ridden on the slicks in question I would far rather be on a new set of TT900s than a 2 yr old set of slicks.Unfortunately TT900s are going out of production as I understand because only NZ and Australia are using them and we dont use enough to warrant the cost of manufacture.However tyre choice should be just that!If you want to run on 2 yr old slicks that should be your choice Provided its dry,If however it were to rain then I fully agree all bikes should be either on full wets or a dot approved road tyre NOT grooved slicks.The problem I see there is that its hard enough too find spares for the RGs already so where are we gonna find 70+ pairs of wheels and discs? and also are the wets used on them going to have too be 2 yrs old as well?Craig Shirriffs used my bike to do the testing for MNZ and he didnt really even want to ride it with the slicks fitted(wrong profile and in most cases old slicks are unpredictable).The upshot of the test was that both Pirelli and Bridgestone have a tyre available at a reasonable cost that are equal if not better than the Dunlop TT900s(once again personal choice)Im confident if someone were to approach one of the tyre importers with an order for 210 sets of tyres (thats 3 sets each for the south island riders alone per year) they would be only too happy to supply them at a better rate.(The price I was quoted on a pair of Bridgestones through my local shop was almost half the price of TT900s).Or perhaps maybe even run on a controlled tyre.As I said at the start this is only MY preference and Im sure other people have theirs.Dont forget MNZ only have to put rules in place to stop us idiots from hurting ourselves needlessly.Cheers Billy

[Tim 39]

I didn't realise pirelli made a suitable tyre also. 2 year old slicks I have found to be fine, I was using them on my 125 throughout last season, and Glen's are 3 years old! FXR rims do fit rg's im told but im not 100% sure. I guess other than making wets legal, if they have to run on DOT tyres then this could be a chance to get all the tyre manufacturers into the class as well, like the "big classes" there is then good potential to find cheaper tyres or even sponsorship to get all the brand names out there. The other option is running a control tyre, this is in the spirit of streetstock being everything equal and this could bring the tyre cost down, however riders wouldn't get the chance to gain the experience of making tyre decisions based on feel of the different tyres etc

[Sketchy_Racer]

I believe that people should stop worrying about slicks in wet crap.

Your on a 150CC motorcycle, top speed of maybe 160.... Tyres that narrow arent going to hydroplane.. not at that speed.

It's a load of crap. let people run what they want. If they don't care about using slicks in the wet, then so be it...

Its just yet another pain in the arse thing that is making the 'entry' class more effort than its worth.

As mentioned, the only good deacent tyres for these things clock up and easy $500.. and if you want the best... Upto $900

The bikes barely cost that much, but thats the choices.

[MOTOXXX]

I rode on tt900's at levels, and got the back stepping out under power on an FXR!!! Bridgestone battlax make some tires that fit and work about as well

realy?

i rode 2.5 seasons on tt900s at manfield and taupo and never had any of those problems. what pressure were u running them at

[Tim 39]

realy?

i rode 2.5 seasons on tt900s at manfield and taupo and never had any of those problems. what pressure were u running them at

I was running about 30PSI for memory, I think the problem was that I was a bit used to how hard I could push my 125. I'm shocked to see how quickly they wear out too, I noticably wore them out over two days riding!

[vtec]

Well in the vic series they allow up to 250cc fourstrokes. And I used Dunlop GPR 70's, and a Bridgestone Battlax BT090 on my CBR250RR. These both were great. And my dad has just fitted out a CBR250RR with a Metzeler Racetec on the front and a Dunlop GPR A10 on the rear, that combo will be better than what I raced on, can't wait to try it.

With regard to the 150's you could probably run a front GPRA10 or Racetec front on the rear, and then work out something else to put on the front if you can find anything decent that fits. I know Glen ran a GPR70 front on the rear of his KRR150. That would work brilliantly in my opinion. If they take a 120 on the rear, let me know, I've got plenty of awesome Dunlop Sportmax GP fronts that would be better than anything else provided you give them a chance to warm up.

[FROSTY]

From my Personal prospective as a codgy old racer type Im not convinced that slicks work in the rain. Yep I understand about the tyre compound and all that but in a genuinely wet meeting I just can't see how its possible for the tyre to work.Slicks are NOT desighned to work in the rain. My concern is that the people riding these bikes are inexperienced racer who don't know better than to go out in pissing rain on slicks. The talk that they are "only" doing 160 km/h to me is frightening.
Ignoring the clear financial issues of buying treaded tyres instead of using donated slicks A good set of treaded tyres should last 2 full seasons.
If Im ill informed I apologise
The last thing I or Im sure any other racer would like to see is this fantastic race class crushed by financial constraints

[sAsLEX]

I believe that people should stop worrying about slicks in wet crap.

Your on a 150CC motorcycle, top speed of maybe 160.... Tyres that narrow arent going to hydroplane.. not at that speed.

It's a load of crap. let people run what they want. If they don't care about using slicks in the wet, then so be it...


Hmm well I ride 1.25 inch slicks every day. I live in England at the mo and it rains every day. Slicks, even on light bikes and skinny sizes, do offer rather reduced levels of grip in the wet. The propensity for the rear to over take the front is greatly exacerbated as well, and for a learning level class this might not be ideal.

[Kickaha]

From my Personal prospective as a codgy old racer type Im not convinced that slicks work in the rain. Yep I understand about the tyre compound and all that but in a genuinely wet meeting I just can't see how its possible for the tyre to work.Slicks are NOT desighned to work in the rain. My concern is that the people riding these bikes are inexperienced racer who don't know better than to go out in pissing rain on slicks. The talk that they are "only" doing 160 km/h to me is frightening.


They may not be designed to work in the rain but they do, and they work very well on low powered light bikes even if it's pissing down, I've raced on them plenty of times and so have a lot of others down here

in fact I've had guys fall off in front of me that were on treaded tyres

[Buddha#81]

in fact I've had guys fall off in front of me that were on treaded tyres

Who would that be refering to? I'm with Kick slicks offer very good traction on low powered bikes, more than most riders give them credit.

On a side note the sooner the S/S dudes go to treaded tyres the sooner the supply of slicks will return to the bucket guys.:dodge:

[FROSTY]

They may not be designed to work in the rain but they do, and they work very well on low powered light bikes even if it's pissing down, I've raced on them plenty of times and so have a lot of others down here

in fact I've had guys fall off in front of me that were on treaded tyres
I'm hearing ya dude.I just can't see how its possible
I think its one of those cases like the bumble bee--its not soposed to be able to fly but yet it does

[sAsLEX]

I think its one of those cases like the bumble bee--its not soposed to be able to fly but yet it does

That's what happens when you make assumptions and simplifications to help your math and physics describing how silly BBs are when out on the piss and because of your status your statement becomes world famous.....


The story goes that a noted Swiss
aerodynamicist, whom McMasters does not name, was talking to a biologist at
dinner. The biologist asked about the flight of bumble bees and the Swiss
gentleman did a "back-of-the-napkin" calculation of the kind I described
earlier, assuming a rigid smooth wing an so on. Of course he found that
there was insufficient lift and went off to find out the correct answer.
In the meantime, the biologist put the work around that bees could not
fly, presumably to show that nature was greater than engineering, and the
media picked up the story. The truth, then as now, wasn't newsworthy, so a
correction was never publicized


John H. McMasters (Boeing) gave an
account of the back-of-the-envelope calculation in an article in
American Scientist a few years ago. Having done a decent survey of
the literature on insect flight, I find the account entirely credible.
But insect flight aerodynamics are fraught with complexities -
continuously changing angles of attack, interactions of opposite wings
at the top of the stroke, issues of how many chord lengths of travel
are needed for full lift to be developed, vortex shedding and
reformation (with opposite sign) at the bottom of the stroke, spanwise
flow, etc., etc. All of which makes back-of-envelope calculations
next to hopeless.

[FROSTY]

Saslex---Geez boy you need a hobby or something--You got WAAAY too much free time :gob:

[Tim 39]

A good set of treaded tyres should last 2 full seasons. This is the problem, the treaded tyres only last about 7 meetings for a competitive rider! whereas the slicks wer lasting a full season.
and I watched Joseph Blackburn (a 150 rider when I was riding them too) kneeslide almost every corner of teretonga in the wet on slicks! a guy on tt900's fell off trying to keep up (against logic but it happened)

[Ivan]

One issue I see,

150 street stock the entry class alot of beginners,

A slick is designed for a warm track surface to offer the most contact patch to the ground and the tire is warm so sticks,

when its wet yu have a layer of water between your slick and your contact area of tarmac,


A wet is designed to be used in these conditions,

It is cut and the compound is softer to grip at lower temps and speeds,
The cuts are designed to pump water aside for more grip level on the ground but also these grooves when water running through them cool the tire,


160 ks is still fast for limited grip

I say keep it as productuon tires

[FROSTY]

Was that the teratonga round of the nats tim??---

[Tim 39]

Was that the teratonga round of the nats tim??---

nah this was the 2005 nationals, but it was of course...wet (bit of a pattern here)

[oyster]

By design or by accident, (who knows), the South Island Streetstock program is very successful. It's still growing, it's training and support culture is hugely in excess of anything MNZ requires, and it's producing a lot of fine young riders. But most importantly, it has a very good safety record. We think this part is certainly no accident, a lot of work goes into this. So we can say with confidence that characteristics of tyres, all types, all conditions has been well analysed, and most, if not all accidents are investigated. From this comes the finding that TT900GP ridden hard canlast as little as 2 meetings before their capabilities rapidly fall off. And of greatest concern is that they become absolutely lethal in the wet. In contrast, grooved slicks are very predictable, and perform well, wet or dry until they're thoroughly worn out. Which in the similar "hard riding" case, takes about 4 times as many k's.
Consider the situation of the 13 year old lap record holder who put 36 entries in his log book before his 14th birthday, racing over 3500km on his Streetstock bike alone. Keeping SAFE tyres up to this rider is a pretty daunting exrcise. Sorry if I offend, but ALL of the critics of slicks in wet, have either no experience of Streestock / Min Road Race on slicks in the wet, and/or have not investigated the safety record of such practices under the program run in the South Island, in the last few years.

[Tim 39]

One issue I see,

150 street stock the entry class alot of beginners,

A slick is designed for a warm track surface to offer the most contact patch to the ground and the tire is warm so sticks,

when its wet yu have a layer of water between your slick and your contact area of tarmac,


A wet is designed to be used in these conditions,

It is cut and the compound is softer to grip at lower temps and speeds,
The cuts are designed to pump water aside for more grip level on the ground but also these grooves when water running through them cool the tire,


160 ks is still fast for limited grip

I say keep it as productuon tires
to take the flip side of the technical approach, slicks are designed for racing and DOT tyres are designed to ride to work and back

[FROSTY]

By design or by accident, (who knows), the South Island Streetstock program is very successful.
Not blowing smoke here mate BUT I for one know damb well why the program works so well and its your doing.
Re the tyres.My experience in running slicks is limited to bucket racers and bigger machinery.In both cases The slicks were orrible in the wet

[Buddha#81]

Not blowing smoke here mate BUT I for one know damb well why the program works so well and its your doing.
Re the tyres.My experience in running slicks is limited to bucket racers and bigger machinery.In both cases The slicks were orrible in the wet

You obviously ran different slicks than we do on buckets down here. I (along with several others) ran slicks a Teratonga in standing water and at several other wet meets and have never had an issue with slicks in the wet. I have more confidence in slicks in the wet than ANY road tyre. I wouldn't mind trying a set of wets to see how good they are.........

[Sketchy_Racer]

Isn't quite funny that the only people that have a opinion against it are the ones that don't have any experience in the situation??

The proof really is in the pudding.

I guess some are just to ignorant to see that maybe

[Sketchy_Racer]

One issue I see,

150 street stock the entry class alot of beginners,

Yep your right, so why are they trying to make it more expensive? Young riders can barely afford a set of second hand slicks, let alone $900 worth of TT900s..




A slick is designed for a warm track surface to offer the most contact patch to the ground and the tire is warm so sticks,

when its wet yu have a layer of water between your slick and your contact area of tarmac,



A slick has no grooves, so that the tyre can have as much surface area touching the ground at one time. that is reagardless of tempeature.

The fact of the matter is, 125s slicks are never going to get to optimum opertating tempeatures on 150s. alot of the tyre is unused and is acting as a massive heat sink for any temp that does get put into the used part of the tyre. Wet or dry, thats always going to happen. does that mean they shouldnt use slicks in the dry either?

When it is wet, you have a layer of water between any tire you use, regardles of what type it is!




A wet is designed to be used in these conditions,

It is cut and the compound is softer to grip at lower temps and speeds,
The cuts are designed to pump water aside for more grip level on the ground but also these grooves when water running through them cool the tire,

Personally, i think that the grooves in wets have very little to do with the 'pumping' of water. With the contact patch of a 50c piece, there aint going to be stuff all water in the way. Sure it would move a little but not much.

Without researching it, i believe that 90% of the reason that they put grooves in wets to reduce the amount of rubber on the tyre to be heated.

It's a lot easier to heat them up than one big block. again, race tyres are designed to run at a temp and even if 150s ran 125 wets i still doubt they would get upto the correct temp, making the tyre about as useful as at slick.

Who knows because both tyres aren't running at the correct temp, all the grooves could be doing is removing surface area for the tyre to contact the road, and the slick with no groves offereing more surface area could offer more grip.. Who knows..



160 ks is still fast for limited grip

I say keep it as productuon tires

160ks is fast.. but 280 on a superbike with limited grip is even faster.

No matter what tyre you are on, if its wet, there is going to be a reduction in grip levels. Every single tyre has a level of grip regardless of make/design, and every rider needs to know that level and ride past if they want to stay on.

I say keep slicks. Tried and prooven

go away saftey nazis

[Flyno]

Glen, the grooves in a wet, DO ALOT! they push all the water out from under the tire, so in the rain the wet can get a better contact patch, hense better GRIP!

[Bykmad]

The grooves pump water away from the contact patch. Slick tyres do not move any water, they simply run across it, rendering them very likely to aquaplane.. Wets pump a lot of water when new, but as the sharp edge is worn off the grooves, they move less water. Wets are also a softer compound, to allow the rubber to grip better in the cooler conditions generally encountered during rain.
The difficulty faced here by MNZ is that the original rules stated that DOT road approved tyres MUST be used. The rules for street stocks were never changed, but the tyre rule interpretation was allowed to "evolve". Now we have the situation that ALL the South Island "Juniors" are running to a different set of rules to that contained in the MNZ GCR's.
NOW FOR THE CRUNCH!
If a rider is killed, the coroner reviews the Police report on the death. The Coroner looks at the organisation of the race meeting, the safety standards applied and the relevant rules for that racing class. It does not take a Rocket Scientist to realise that if the tyre rules have not been enforced, that someone, somewhere, is in the gun! That someone, is the Steward and the Clerk of the Course. The end result is that one or both of the Steward and Clerk of Course could, Probably will (as they are not Labour Party Caucus members) be charged with manslaughter.
Don't laugh. I spent a number of years working in the Coroner environment and they look at rules being rules, not simply guidelines.
Get together and have the rules moulded into an acceptable template, but also realise that a Coroner in an inquest can ask questions as to why a rule was changed.

BE VERY CAREFUL. We are in a fantastic Sport which has inherent dangers.
Think about the changes you want to make.

[sAsLEX]

The grooves pump water away from the contact patch. Slick tyres do not move any water, they simply run across it, rendering them very likely to aquaplane.. Wets pump a lot of water when new, but as the sharp edge is worn off the grooves, they move less water. Wets are also a softer compound, to allow the rubber to grip better in the cooler conditions generally encountered during rain.
The difficulty faced here by MNZ is that the original rules stated that DOT road approved tyres MUST be used. The rules for street stocks were never changed, but the tyre rule interpretation was allowed to "evolve". Now we have the situation that ALL the South Island "Juniors" are running to a different set of rules to that contained in the MNZ GCR's.
NOW FOR THE CRUNCH!
If a rider is killed, the coroner reviews the Police report on the death. The Coroner looks at the organisation of the race meeting, the safety standards applied and the relevant rules for that racing class. It does not take a Rocket Scientist to realise that if the tyre rules have not been enforced, that someone, somewhere, is in the gun! That someone, is the Steward and the Clerk of the Course. The end result is that one or both of the Steward and Clerk of Course could, Probably will (as they are not Labour Party Caucus members) be charged with manslaughter.
Don't laugh. I spent a number of years working in the Coroner environment and they look at rules being rules, not simply guidelines.
Get together and have the rules moulded into an acceptable template, but also realise that a Coroner in an inquest can ask questions as to why a rule was changed.

BE VERY CAREFUL. We are in a fantastic Sport which has inherent dangers.
Think about the changes you want to make.

So change the rules to how it is currently run. Simple.

[Sketchy_Racer]

Slick tyres do not move any water, they simply run across it, rendering them very likely to aquaplane..

If you can get a street stock 150 tyre to aquaplane, i'll give you $100!!

Considering the actual contact patch of these narrow tyres is about the size of a 50c piece.. im seriously failing to see how it could aquaplane. Even at 160kph.. I just can't see it happening. and from what the last 50 juniors on slicks in the wet have proven, it doesn't happen.

Honestly, if we start making them run DOT approved tyres, a lot of them are only going to able to afford some of the crappiest crap (which still cost 5x the amount of the slicks) We will see 10x more crashes. Even some of the more expensive tyres (conti citys) give the crappest wet grip i have ever ridden

My opinion is based on experience.

I don't know the technical, but i know from experience that i'd be paying a shit load more to be riding on slicks in the wet, rather than A DOT approved tyre like a conti-city.

[oyster]

Before my time, but I believe Tim Gibbes "invented" Streetstock for the very successful "Suzuki series" I have a program here dated 2001. The rules are clear, the tyres must be Dunlop tt900GP. Nothing else allowed.
When the rules went into MNZ rulebook, the tyre rule was dropped. Check yourself, no mention, so in fact tyre rules could easily be interpreted as "open tyres" as per F3,4,5. All of these similarly have no definition.
Yes, we all all know production classes traditionally have road legal tyres, but rules are rules, and tradition has no place here! MNZ left the door open by not carrying through Tim Gibbes rules.
In the South Island we saw that opportunity, but as we went along we took out the ambiguity by getting Supp rules, allowing slicks. At the National meeting that created all the fuss, there was no rule breaking, the Supp rules were in place to be sure. We were advised by MNZ the year before that the tyre rules was at least ambiguous, (even though we had Supp rules that year too) so we were to "tidy them up" which we did.

[oyster]

Sketchy came down for the last National round and we put him on the same bike he recently finished the Vic Series, I think he did a pretty good time, a 1.57, which is around 3 seconds off the lap record (actually set the on the very same bike.) In qualifying a youngster on an RG with grooved slicks went out and did a 2.05 in the RAIN. Not just wet, but RAINING. And I believed him, he said it was "easy". Now equate that to Manfeild, a fair "conversion" of that lap time would be around 1.32 or 1.33. You Vic club guys, has anyone done a time like that around there in the RAIN? Would you really want to try that after you've done about 4 meetings of absolute thrashing (1.26's) of the DOT tyres? No, the treads become absolutely lethal in that situation, that's the basis of our concern that makes us request tyres to be "Open" (but no wets) for Streetstock. Wot you say Sketchy? Do you remember Tom's performance?

[FROSTY]

Oyster--I Think its fair to say that the streetstock tyre issue has come up as a result of the Teratonga round of the nationals.
The MNZ guys were I think "unfortunately" positioned round the track when the 150's raced.
They saw the crashes on the last corner before the back straight in the wet AND they saw the bikes shimmying around on the slippery section of the back straight. I must say from my pits it looked prety scarey.
Is there a tyre available that could be purchased in bulk for SS bikes??
Some sort of custom "cut slick" kinda like the Metzler racetec?

[Sketchy_Racer]

Damn straight i remember Toms performance. And what a performance it was!!

One of the deciding factors that have given me the opinon towards this matter that i have.

I just can't see why people can't look for the proof in the pudding. It's really not that hard to see.

[Sketchy_Racer]

Oyster--I Think its fair to say that the streetstock tyre issue has come up as a result of the Teratonga round of the nationals.
The MNZ guys were I think "unfortunately" positioned round the track when the 150's raced.
They saw the crashes on the last corner before the back straight in the wet AND they saw the bikes shimmying around on the slippery section of the back straight. I must say from my pits it looked prety scarey.
Is there a tyre available that could be purchased in bulk for SS bikes??
Some sort of custom "cut slick" kinda like the Metzler racetec?

I will personally give you $100 if you can get a streetstock to 'aquaplane' (assuming thats what you mean by shimmying around)

Looks are nothing. A superbike looks scary going past a 280 clicks. Ask the riders. Its the riders problem at the end of the day, and of the whole feild is comfortable, and feels safe wheres the problem?

And, the crash record for SS150 i bet would probably be quite a sight better than say F3, or F2.....

[Kickaha]

So how many bikes have crashed in the wet on wets or treaded tyres? I know I've seen a few

best we only race on dry days from now on

[Sketchy_Racer]

Don't joke too much there Kick.... if things keep going this way... ya just never know

[Buddha#81]

So heres a curveball...... young Jimmy on a RG150 on a cheaper dot approved tyres bins it and unfortunatly sustains head injuries....... Jimmys Mum and Dad turn off the life support and the Police and Coroner start their inquiry the Tyre manafacturer is contacted........ "What do you mean, those tyres are high performance street tyres, they were never designed to be on a race track".

Oh maybe we should be racing on race tyres.

[oyster]

Frosty, we investigate EVERY incident / accident in Streetstock. (That we practically can) The Steward came to me after that practice and said there were 3 accidents, supporting the concerns of some riders who'd spoken to him.
I followed up and found:
1) Ran out of fuel
2) Fell off on treaded tyres.
3) Fell off on Slicks. A novice rider (only 5 meetings), on the first lap, got back on and qualified 2nd on pole. I don't think there was a tyre problem here....

Spud. This is not a "curved ball", this is reality. I fixed a flatty for an Invercargill youngster the other day. A virtually new tyre, it ran about 3 mm out of shape and took 100 grams to balance. It was a rear so I let it go. If it were a front, I would put a knife through it. Theses tyres are just glorified commuter tyres. The speed rating for TT 900 is only 180km/hr for 1 hour,
so imagine an endurance race at a fast track like Puke with far greater than road stresses. People confuse these tyres with the ones produced for Sport Production racing which are really race tyres made road legal. Not the other way around.

[Tim 39]

Yea the bit that amuses me is that we can't use slicks in the wet because the manufacturer intended them for dry weather. well the manufacturer intended for these tyres to be ridden to work and back with, not for racing.....so where do they fit in? to be honest it's all political bullshit, I'm not blaming MNZ because it's not their fault that our justice system punishes anyone and everyone

[oyster]

We got the argument "But these kids will never learn proper wet riding like that"
Ashley Weller, a 15 year old very new to a 125GP. In his only second ever National Points race, first time ever on wet tyres. Goes out in Sunday warmup on wets. A few little tips, all good Ashley? Yep, cool.
What does he do, goes out and wins the race. Se ya later Cameron Horgan, Andy Evans, Maarty van Booma.
Of course Ashley just appeared out of a cabbage patch......

[JayRacer37]

So heres a curveball...... young Jimmy on a RG150 on a cheaper dot approved tyres bins it and unfortunatly sustains head injuries....... Jimmys Mum and Dad turn off the life support and the Police and Coroner start their inquiry the Tyre manafacturer is contacted........ "What do you mean, those tyres are high performance street tyres, they were never designed to be on a race track".

Oh maybe we should be racing on race tyres.

So you reckon we should'nt be racing on DOT prod racing tyres? in 600SS?
Just cause its got DOT approval doesn't make it road applicable...I couldn't think of much worse than riding a full SS DOT tyre on the road.
I rekon MNZ IS spot on in there apprasal, and following rule ammendments, because a 125 slick is NOT designed in any way to be used on a 150 rim, or application, and at least with a proper road tyre it has been designed to have some wet application.

When you start throwing pretend race tyres like the TT900 in there, boarders are going to become blurred, cause you have effectivly a DOT race tyre. This makes it expensive, like a slick, and also give the life of a race tyre. Whilst the grip is going to be great in the dry, its going to fall off as bad as a slick given damp - this is the nature of tyre and COMPOUNDING, not tread, as Glen so rightly pointed out further back.

The nastist part of what the SI StreetStock guys have been doing is that you have a god knows how old, god knows what condition, or how stron g tyre after the 'grooving' has been done to them....with experience on buckets, with our OWN used 125 slicks (so we knew the history of them) after a few uses some of them just turned bad, no reason, or logic, just didn't work....something went off. That was around half of the tyres we used. How many 150 are running round out there like that.

On the same note when a 125 slick that has been hand cut delaminates and throws little johnny off and gives him head injurys, how do you think the coroner will see that....a tyre in the wrong application, with its roading surface tampered with, in innapropriate conditions for that tyre, that has failed with a combonation of these factors...at least MNZ are providing a guideline that will have tyres that are at least predictabe, and in a safe condition, AND designed for bikes of that specific nature out on track. Not god knows what. Regaredless of how fast Tom can go in the wet on a 125 slick.

[ajturbo]

wow... lots of big words out there!

years and years ago..(last centry) i was racing a mate's bucket it was the second fastest one on the track (the bike NOT me).. it had a slick on the front and a yoky on the rear... the water was flowing OVER the rim when we stopped... it was DEEP!.. that was on the fastest corner... the only wheel that was sliding was the rear!!!.. work that out!!!..

luke and i are using the tt900... i think i have a battle thingy on the rear, my bike took out the the ss class last year..( i think)...

luke has dropped both bikes... too hard with cold tyres..

but we haven't used them in the wet YET... that will be fun, hope there will be some-one with a camera on luke then.. to catch all his falls! hahahaha..

on that note... it looks like we ARE racing the SS this weekend .. RAIN or SHINE....

it is amazing what a couple of emails can do eh!:innocent:

[oyster]

Years ago I worked for a company well known for it's clever engineering design
In the foyer of the design office, a little sign was there
"Would the person who says it can't be done, please not disturb those who are busy doing it."
Jay, your theories of "why it won't work" are not borne out of (our) experience.
Over about 4 years the South Island Streetstock has grown, it'll top 100 bikes very soon. That's one hell of a lot of experience, and believe me, our highest priority has always been safety. Minimum crash rate is ALWAYS at the top of the list. We've also seen the use of quite a good mix of tyre types, riding abilities and track conditions. Our overwhelming conclusion is that we have a higher crash rate with treaded tyres than slicks. So you can see why a lot of parents are cranky about the new rule, they have every right to believe safety will go BACKWARDS as a result.
Your tech comments are mostly wrong, the slicks we use are actually a closer fit than the Dunlops (reference to original specs) The grooving process is closely defined with dimensions and tolerances. We've checked it out, these tyres ARE designed to be grooved as an option. All around the world, and locally here in Karting, grooved slicks are approved as a "Legal" wet tyre

[Tim 39]

So according to this new tyre rule, you can run a decent tyre on the back like a super corsa or rennsport (DOT approved) and just have to find a tread for the front. much better than the likes of a tt900 on the back. is this correct Pete? because a lot of the streetstock guys already have supercorsa's on the back anyway

[Ivan]

Ok,

Jay seemed pretty spot on what he said about tires,

I am not going to say they are right or wrong on a internet forum, without riding on both,

But hear is what I am going to say,

I raced my RG150 with a set of MT75s on it went good gripped well and worked.

I brought Jays RS125,

Front Slick has been cut,


When pushing it in the corner at 1:21's at Manfield which is no were near lap record pase.

The front will be gripping then suddenly let go, over and over again.

Now I put this down to the fact that the tire has been grooved,
And to proove my point I have checked the tire in spots it has started to fall apart as such it has worn alot quicker in certain areas on the tire than the other and in between these grooves, I might have one patch of poor contact at full lean angle, but tire spins past this groove I have better contact if you get my drift.

What I am trying to say is my opinion on these tires is ok, except the poor grip and meaning slower lap times.


The only thing I dont understand is how streetstock meaning a production road bike class can allow a GP race tire????

Im not picking at you either Oyster,
Good on you for doing what you do for the young guys Im just tryign to say something

[ZorsT]

The only thing I dont understand is how streetstock meaning a production road bike class can allow a GP race tire????

The class is designed for youngsters. Youngsters with little money.

Used slicks are cheaper.

This means more people can afford to race.


Peter,
If every rider that was going to use slicks signed a disclaimer, would that get everyone off the hook?

[k14]

I brought Jays RS125,

Front Slick has been cut,


When pushing it in the corner at 1:21's at Manfield which is no were near lap record pase.
No, Ivan. The reason the front is so crap is because it has been on there for like 3 years and I don't know how many kms. The dunlops go off noticeably after about 300kms and who knows how many kms you've put on it. The tyres aren't the reason you're doing 1.21's around there, you're the reason!

Those dunlop slicks are made to have grooves cut into them (as someone else earlier stated). All the gp teams do it from time to time and I've not heard of one case of delimanation etc caused from cutting a slick.

This is quite a controversial topic and I can see both points of view. In the end there is no right answer, whatever the outcome someone is not going to be happy. I hope it works out the best cause the streetstock class is awesome. Bringing through some good competition (ivan excluded) for 125's.

My only experience of slicks in the wet (not on my RS) was at teretonga last year in 1 or 2 degree temps and complete downpours. I could take the first corner flat in top gear (alright only about 110kph with a tail wind) without so much as a hint of a slide. All the races that day were in very similar (and damp conditions) and not one moment, riding near the front of the buckets and ahead of a fair few streetstock riders. The same day I crashed my RS riding on wets :shit:

[Tim 39]

I brought Jays RS125,

Front Slick has been cut,


When pushing it in the corner at 1:21's at Manfield which is no were near lap record pase.

The front will be gripping then suddenly let go, over and over again.

Now I put this down to the fact that the tire has been grooved,
And to proove my point I have checked the tire in spots it has started to fall apart as such it has worn alot quicker in certain areas on the tire than the other and in between these grooves, I might have one patch of poor contact at full lean angle, but tire spins past this groove I have better contact if you get my drift.

What I am trying to say is my opinion on these tires is ok, except the poor grip and meaning slower lap times.


The only thing I dont understand is how streetstock meaning a production road bike class can allow a GP race tire????


A few holes in that statement Ivan... world 125GP riders use hand cut slicks "intermediates" i.e Mika Kalio got second at le mans last year on one.

have a look at any treaded/grooved front tyre, you will find exactly the same "falling apart" takes place. I think this is because the front tyre only gets pressure one way (braking) the rear gets both so wears evenly..I'm not sure just a guess, because every single treaded tyre I've seen it happen to.

I'm assuming that when you changed your front tyre to a slick, or road tyre that you were doing far better lap times?

the 600 sports PRODUCTION class and the pro twins class are both allowed Race wets, that clearly aren't Dot approved. Good enough for some, good enough for everyone else.
Thats my opinion (doesnt matter because the rules are already decided and no amount of my bitching will ever change that!)
I believe there are suitable road legal race tyres for the rear available but not for the front as yet.
This tyres thing is a very controversial subject

[Tim 39]

No, Ivan. The reason the front is so crap is because it has been on there for like 3 years and I don't know how many kms. The dunlops go off noticeably after about 300kms and who knows how many kms you've put on it. The tyres aren't the reason you're doing 1.21's around there, you're the reason!

Those dunlop slicks are made to have grooves cut into them (as someone else earlier stated). All the gp teams do it from time to time and I've not heard of one case of delimanation etc caused from cutting a slick.

This is quite a controversial topic and I can see both points of view. In the end there is no right answer, whatever the outcome someone is not going to be happy. I hope it works out the best cause the streetstock class is awesome. Bringing through some good competition (ivan excluded) for 125's.

My only experience of slicks in the wet (not on my RS) was at teretonga last year in 1 or 2 degree temps and complete downpours. I could take the first corner flat in top gear (alright only about 110kph with a tail wind) without so much as a hint of a slide. All the races that day were in very similar (and damp conditions) and not one moment, riding near the front of the buckets and ahead of a fair few streetstock riders. The same day I crashed my RS riding on wets :shit:

some of that was what I was going to say but didn't have the guts! (and I didn't see yours before I submitted mine :( )

[oyster]

With the meeting to discuss all Streetstock rules confirmed for Chch on 18th Aug, this thread is bring out some really good input. Keep it up, from all angles. Thanks
Tim
Yes, 600 front tyres work extremely well on 150's. My son did 3500km on his KR150 with these courstesy of big bro's pile of old tyres. Much better than TT900 in every way. Wait, no doubt the experts will tell us otherwise, like bumblebees can't fly etc.... Anyone with a pile of 600 fronts for sale, PM me now! We need them!
Ivan
Tread pattern on grooved slick really important. We developed a very simple and effective one. Great results in all conditions and no wear or structural failures.
See earlier posting, Tim Gibbes rules specified tyres, MNZ doesn't. But to be sure we got Supp rules anyway.
Zorst
Sorry, safety is FIRST, economy second. But we like them both of course!
We have solid stats that show overall slicks are safest on these bikes, all conditions.
But supply of slicks will son be a problem as we approach 100 bikes in the South. So it's sensible to search for a safe and economic alternative to SUPPLEMENT slicks. This process is underway. MNZ were to study this as part of the rule change but said it "wasn't practicle" Bollocks, we're getting it sorted, just need a bit of time.

[Tim 39]

Pete, Metzeler rennsport make a 110 front tyre instead of the 120's they fit well and work well too. just in case you end up having to buy new tyres rather than ex 600 fronts

[Ivan]

As I said,

I am not here to pick faults at anyone, I believe Peter has done an awsome job in what he has done for the youngsters,

My Question wasnt a lame question it was one asked seriously to see and I got a answer which is great, Sweet now I see why, it makes sense cheap slicks young riders no money...

K14...................


I have posted things I find serious on the tires, I have talked to Jay before about these issues and he agreed that front does the same.

Now yes, Tires are old yes, I didnt care tho I had no money I had enough money to run the bike.

I posted my post to just say somngand ask a question,

In future I would like it if you would NOT publicy insult me,
I have taken tooooo much shit for to long now from people and it is FUCKING me off,

[oyster]

Tim.
Great, that's a good idea re 110 size tyres. One of the problems with the TT 900 are they're too small at 100/80. The original RG are 110/80, and the slicks we fit are 115/70, slightly wrong shape of course but same circumference, in both axes. Bridgestone has the same problem, only 100 or next size (way too big) 120 available.
Ivan.
Good on ya making it clear you don't appreciate insults. You deserve respect big time, I understand you contribute at club admin as well. People like you are rare, keep it up. Don't worry, you won't lose any friends from these insults, you'll only gain some GOOD QUALITY ones. That's what counts.

[JayRacer37]

With the meeting to discuss all Streetstock rules confirmed for Chch on 18th Aug, this thread is bring out some really good input. Keep it up, from all angles. Thanks.

Can you see any postives from the new ruling Pete? Being, quite clearly, the man on the scene?


Yes, 600 front tyres work extremely well on 150's.

Even though the 600 tyre works quite well, it does LOOK rather horrible in profile on the bikes. Also, with the tyre clearly stating 'FRONT' on the sidewall, do you think you might have any legal and/ruling problems with these being used on the rear?

[cowpoos]

If you can get a street stock 150 tyre to aquaplane, i'll give you $100!!



I'll take you up on that...let me borrow ya Kr next time I'm down!! I have a dastardly plan!!

[Sketchy_Racer]

ahhh...

Buddy the KR has long gone..

And your to fat to fit on the 125...

[ajturbo]

ahhh...

Buddy the KR has long gone..

And your to fat to fit on the 125...
and you wouldn't want him to break it..... woops too late,

[Clivoris]

What a great thread. It seems that your experience down South Oyster goes contrary to logic, but has lots of good evidence to support what you are doing. That can't be argued with. The biggest difficulty I can see is that, as others have suggested, if the worst ever happens and a coroner looks at information like tyres being used for other than original purpose, somebody is in the shit. Most especially, after a report commissioned by MNZ specifically recommended otherwise. If I was an MNZ decision maker I would be very nervous about changing the ruling.
I'm no lawyer, but "logic" would suggest that the original report for MNZ has missed some important information and MNZ will need a report that addresses these missed bits. If MNZ has this information documented, as well as clear documentation of the debate and any process that they went through to change the ruling, a coroner would be able to look back at this and conclude that a robust process was gone through with good intent. This tends to be very important in my field (health) where life and death decisions are made. The translation being, you can go against what "logic" or training might otherwise suggest as long as you have the decision making process and rationale documented; and it seems that it was a reasonable thing to have done in the circumstances. A documented risk/benefit analysis of the various options is always useful too. I hope that I have communicated this clearly.
You may already have such a report, and I would think about appending this thread to it.
Good luck. I'm certainly shifting backwards and forwards in this debate.

[oyster]

Clivoris. Yep, you're easily understood, and dead in line with our thinking, as as we've presented to MNZ. I used a saying in an earlier posting "by accident or by design". This really means if we were starting from scratch we'd think differently, but we're not, and as a result have good statistics to show what works and what doesn't. This is why we want to use race tyres for racing (surely no problem here?) and grooved slicks for the wet (as used in other classes, countries and in Kartsport NZ) as a safe tyre in wet conditions.
As you say, all that's needed is thorough testing, compiling of existing statistics and someone trusted to "sign off". Then, not only do we have something safe, but the butts are covered as well. Don't worry, all this has been done and said by us, that's why we've appealed and have this meeting on 18th August, where hopefully all is resolved. For the record, we had our worst ever raceday for Streestock at Levels on the weekend. 35 riders, 4 major crashes. 1 nothing to do with tyres, the other three all on TT 900 GP tyres. Same analysis for all "no warning, it just let go suddenly"

[vtec]

Well I know a lot of the Streetstock bikes use 110 profile tyres, but I've got quite a few 120 profile front supersport tyres for sale that if they fit might work brilliantly on the back of a 150 streetstocker, extremely grippy and way tougher than is required for a 150.

[Tim 39]

I've got quite a few 120 profile front supersport tyres for sale that if they fit might work brilliantly on the back of a 150 streetstocker, extremely grippy and way tougher than is required for a 150.

are they supercorsers?

[ajturbo]

Well I know a lot of the Streetstock bikes use 110 profile tyres, but I've got quite a few 120 profile front supersport tyres for sale that if they fit might work brilliantly on the back of a 150 streetstocker, extremely grippy and way tougher than is required for a 150.
one of the vic club's bikes is running a 120.. it seams to work ok..

[ajturbo]

Clivoris. Yep, you're easily understood, and dead in line with our thinking, as as we've presented to MNZ. I used a saying in an earlier posting "by accident or by design". This really means if we were starting from scratch we'd think differently, but we're not, and as a result have good statistics to show what works and what doesn't. This is why we want to use race tyres for racing (surely no problem here?) and grooved slicks for the wet (as used in other classes, countries and in Kartsport NZ) as a safe tyre in wet conditions.
As you say, all that's needed is thorough testing, compiling of existing statistics and someone trusted to "sign off". Then, not only do we have something safe, but the butts are covered as well. Don't worry, all this has been done and said by us, that's why we've appealed and have this meeting on 18th August, where hopefully all is resolved. For the record, we had our worst ever raceday for Streestock at Levels on the weekend. 35 riders, 4 major crashes. 1 nothing to do with tyres, the other three all on TT 900 GP tyres. Same analysis for all "no warning, it just let go suddenly"
luke did the same thing... running tt900!..... but he was driffting the rear coming out of corners BEFORE that.....(presure to low/high?)

[Tim 39]

id be suprised if it was drifting due to tyre pressure (unless quite a wee way out) usually just overworn treads seem to have that effect