Streetstock tyres..

**oyster** · 16th July 2007, 21:42

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** · 16th July 2007, 22:28

Originally Posted by spud racer

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** · 16th July 2007, 23:13

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!

**oyster** · 17th July 2007, 10:59

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** · 17th July 2007, 15:57

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** · 18th July 2007, 09:45

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** · 18th July 2007, 11:03

Originally Posted by Ivan

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** · 18th July 2007, 11:07

Originally Posted by Ivan

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

**Tim 39** · 18th July 2007, 11:17

Originally Posted by Ivan

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** · 18th July 2007, 11:20

Originally Posted by k14

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

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** · 18th July 2007, 11:41

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** · 18th July 2007, 11:52

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** · 18th July 2007, 12:08

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** · 18th July 2007, 12:29

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** · 18th July 2007, 18:22

Originally Posted by 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.

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

Originally Posted by oyster

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?