MNZ requests ProTwin comments

[GSVR]

CONSTRUCTIVE COMMENTS REQUESTED
Motorcycling New Zealand road-race commissioner Paul Stewart has requested that you send constructive comments with reasons on the following, please forward your comments to MNZ.

http://www.motorcyclingnz.co.nz/news2.aspx?SectionID=29&ArticleID=12167


All the interested partys in ProTwin have the opportunity to have a say and put their veiwpoints forward.

Cheers to Paul Stewart.

Theres also comments requested on other stuff...

[johnsv650]

good one paul stewart, i will send my thoughts away and the more people do the better......

[steveyb]

I have made some comments.
Overall I think the concept is sweet as and works well overseas.
I just commented about making the rules, whatever they may be as I am not involved directly in the class other than trying to sort out a protest at NZSBK Rd 1 this year as riders representative, unambiguous so there is no room for interpretation.

e.g. the tyre rule; Either say what tyres are allowed specifically, or say it is open. No ambiguity then.

Cheers

Steve

[GSVR]

F3

So what are peoples thoughts on allowing inline fours to be bored out to 520cc. That gives the twins a 20% dissplacement advantage which is what they get elsewhere in the world apparently.

I also see back in the old days when inline fours where 400cc twins where only allowed to be 500cc max.

[svr]

F3

So what are peoples thoughts on allowing inline fours to be bored out to 520cc. That gives the twins a 20% dissplacement advantage which is what they get elsewhere in the world apparently.

I also see back in the old days when inline fours where 400cc twins where only allowed to be 500cc max.

A couple of points:
1. The F3 championship in 06/07 was won by a 450/4, which was clearly the fastest bike (and would have been this year as well)
2. 650 twins have to have standard intakes, otherwise capacity is limited to 500cc
In my view the F3 formula seems pretty fair at the moment. Its conceivable that any engine option avaible would have a clear advantage given deep enough pockets and some imagination.

[GSVR]

A couple of points:
1. The F3 championship in 06/07 was won by a 450/4, which was clearly the fastest bike (and would have been this year as well)
2. 650 twins have to have standard intakes, otherwise capacity is limited to 500cc
In my view the F3 formula seems pretty fair at the moment. Its conceivable that any engine option avaible would have a clear advantage given deep enough pockets and some imagination.

Of course at the same time SV650s could be allowed to run any intake system they wanted like the 400s already do. Whos to say some aren't already modified in a legal kinda way!

What might happen is some guy might rock on up with a sleeved down or understroked (with slightly longer titanium rods) 2008 600.

[GSVR]

And back onto the ProTwins...

Do you think the idea is for this class is for it to eventually replace F3 like F2 and F1 has been replaced by production classes. Or is it to have a cheap as possible entry level class.

The reason I ask is becuase this will have a huge effect on which way the rules are updated for both F3 and ProTwins.

[koba]

Wouldn't boring 400's to 500+ be expensive with possible reliability issues?
If it is expensive (I dont know thats why I ask) it kinda defeats the purpose if it is done on the grounds of cost...

[Cleve]

What might happen is some guy might rock on up with a sleeved down or understroked (with slightly longer titanium rods) 2008 600.

Gav (HDT) suggested this to me last year and I have always thought it a very clever idea and not sure why some one hasn't tried it (to my knowledge) A 450 cc "R6" with slipper clutch, upgraded suspension etc could be a wicked F3 weapon.

[GSVR]

Take a current 600 with a bore of 67mm and a stroke of 42.5mm.

You would have to go down to a 61 mm bore to achieve a dissplacement of 498cc. Few issues with valves etc maybe but thats not to say it can't be done. To get to 450cc would be an even bigger ask.

BTW I think Gav mentioned the idea to me.

[FROSTY]

Ya can only stretch things so far. A 400 bored to 450 is a frajile enough beast --take another 12.5cc per hole and you got hand grenade city.

[GSVR]

Wouldn't boring 400's to 500+ be expensive with possible reliability issues?
If it is expensive (I dont know thats why I ask) it kinda defeats the purpose if it is done on the grounds of cost...


Ya can only stretch things so far. A 400 bored to 450 is a frajile enough beast --take another 12.5cc per hole and you got hand grenade city.

Obviously the guy thats racing these doesn't think so or he wouldn't have asked MNZ to consider allowing the bigger displacement.

[koba]

Obviously the guy thats racing these doesn't think so or he wouldn't have asked MNZ to consider allowing the bigger displacement.

yeah, guess so aye!

[svr]

Anything is possible if you want (can) spend enough money. The Formula 3 title has always been vulverable to `buying' e.g. arguably the best F3 bike seen in NZ was the Ducati supermono ridden by Rodney O'Conner ('95??). ZXR400 mounted Nathan Spargo was consistently riding around the outside of this thing on his $8k bike in a futile attempt to defend his championship. The only thing really saving the class is an almost tacit agreement not to spend too much money. Purpose-built european `giant' singles racer anyone (50k)??
Aprilia svx 550 bored / stroked to 650cc (ok with standard intake) in pupose-built gp chassis?? or same with 450 svx motor built with an open checkbook (110kg, 90hp).
How far would have to bore out your 20yr old 400 to beat those bikes?

[steveyb]

IMHO we simply must have a Formula racing class of some description.
The main reasons being; it allows people to develop their motorcycle engineering skills and ideas and it allows people to put together bikes that may or may not cost a lot of money in one way or another.

I think that we often lose sight of the fact that motorsport is not only about the riders, the factories or the sponsors, but includes also the engineers, the ideas people and the teams that build and support the machines.

Without the scope to let ideas run free and hands to roam over tools and machinery and lumps of metal then we will all be at the mercy, so to speak, of the major manufacturers and have to ride what they make.

Nathan Spargo, Tony McMurdo, John Britten, Bill Buckley, Terry Fitzgerald, Andy Bolwell, among many others, are all recent and contemporary examples in NZ of the desire to make ones own machine (Many in F3). I even sold my NSR 250, back in the day, to a young fella that installed an Impulse GSX400X engine in that frame with a TURBO on it. And it worked!!!! Not super-well, but I guess he ran out of resources to fully develop it. But the point is that he had an idea, had a go and, at the time, had somewhere to race it!

We have only one international racing class in NZ, (125GP), we have a good production-based class (600 SP), a fairly good production-based Superbike class, an OK beginner class (Streetstock), a new low cost entry class (Pro Twin which seems to work well), where to for those who want to fiddle and fester and let their imaginations wander?

Formula racing at the highest levels must be defended. Remember though that VMCC run under erstwhile Formula 1, 2, 3 rules.

As for the current proposal (high caps for multi cyls), if one is to take that to its logical extension one surely needs to base it on power to weight ratios and maybe power/torque curve comparisons to see where equity in the rules will pan out. 500cc? 520cc? Hell I don't know. But as I recall vaguely, it seemed that for the Kawasaki and the Yamaha that around 480cc was achievable with pretty standard, not too exotic kit? Could be wrong about that.

BUT, cost must NEVER be a part of writing Formula-based rules, that is for the other classes. If cost reduction is a part of your decision process then you should be deciding to be in another class (now that we have the Pro Twin class) so that you can do that, and do it well.

BTW, what about this idea of blanking off one cyl of a current 600 to make a 450 triple? Does that fit the rules? Are there still 4 cyls and hence still 600cc even though one is not working? How would that be ruled I wonder?

Enjoy

Steve

[svr]

IMHO we simply must have a Formula racing class of some description.

BTW, what about this idea of blanking off one cyl of a current 600 to make a 450 triple? Does that fit the rules? Are there still 4 cyls and hence still 600cc even though one is not working? How would that be ruled I wonder?

Enjoy

Steve

Hard to believe it hasnt been done - 90hp R4.5! Just pulling off a plug-cap would make it legal. The 4th `dummy' piston remains as a balancing weight as per supermono.

[FROSTY]

Hard to believe it hasnt been done - 90hp R4.5! Just pulling off a plug-cap would make it legal. The 4th `dummy' piston remains as a balancing weight as per supermono.
Have you tried riding a 600 with a plug cap pulled off?

[svr]

Yep (er not on purpose of course), better than my old kr1 with a yz490 motor!

[Billy]

Yep (er not on purpose of course), better than my old kr1 with a yz490 motor!

Aaah the old 250 proddy days aye.That explains a few things about the speed (or lack there of) of your old proddy bike.Didnt think youd be stupid enough to own up to having one of those!!!

[quallman1234]

Wouldn't you need to take the spark plug out (no compression) completely so petrol wouldn't build up in the top of cylinder and hydra lock it? Or would it just flow out the exhaust valve's

[Burrt Badger]

Wouldnt you remove the rod and piston to reduce drag, Oh and the carb?? Wouldnt be feasible me thinks

[steveyb]

My feeling from an engineering point of view is that one would need to remove the piston and rod from one cyl and replace with a weight of exactly the same mass as that assembly, eg clamped around the crank journal.
Then disable the carb or injector (easy, take off the fuel hose or pull out the power feed) and that 'should' work.
You could take out all the valves to reduce drag and the spark plug too but you would need to replace with seals of some sort so that air and water cannot get it and oil does not come out.

But there will always be a lag when the missing cyl is supposed to fire and doesn't.

Go on ya mugs, give it a go!! But which cylinder do you disable?????

Steve

[svr]

Mechanically I think it would work,
Philosophically I have an issue: There is something deeply wrong with making a bike slower in order to go racing!

[svr]

Aaah the old 250 proddy days aye.That explains a few things about the speed (or lack there of) of your old proddy bike.Didnt think youd be stupid enough to own up to having one of those!!!

Are you referring to my kr-350 Billy?
The 490 was a different animal entirely - 55 hp and 105kg - good in theory but unrideable due to vibration in practice... (KR-1s with balancing shaft removed are pretty bad too - think tz 250G)

Interesting that the guy who built that crf450 road racer told me that it vibrates so bad his arse cant grip the seat so he slides all over the place.
I'm sure an r4.5 would be pretty smooth by comparison.

[oyster]

Hi Vicky.
I've been very interested as it's a progression path from Streetstock (1 path, the other is 125GP)
As an engineer I've been involved in prep of these bikes and have to read/interpretet the rules for people many times as a result.
1) In Canterbury we gave it a really good promo to get it started at club level and was instantly in good numbers as a result. In the last few months quite a few more have joined, 4 of them 16 years old so all good.
What was missing was effective promo to get clubs / riders underway so there was enough for a good national champs.
Mag articles etc are free and work well, but this wasn't done. Not too late, get busy.
And yes, "instant classes" can be made, Tim Gibbes proved it in his "Suzuki Series" in the early 90's. That's my first suggestion,
stimulate industry interest and promote the class.
2) The rules need 10 units sold per year of the model. That excludes the older ones, which obviously are not sold new any more.
The wording needs to be changed to read "in the year it was sold". And no, that's not obvious, overseas there are series that specificaly exclude obsolete models. The manufacturers demand it that way.
3) The fuss about tyres. The rules are clear. If it's a road legal fitment it's OK, if it's not it's not. Simple. It's written. But what is road legal? According to the LTSA there are very few restrictions but for circumference /diameter which must be within 5% of the manufactures original specification. Outside that, no WOF, no pro twin eligibility. Did anyone do the sums on the super big tyres fitted to Karl Morgan's bike? Even though they were grossly overwidth, and hugely outside the TYRE manufacturers recommendations, they were still within the 5% dia, so ultimately were road and pro twin legal.
4) Slotting the cam sprockets is fine, that's just a method of adjusting the engine optimum timing within the engine manufacturers
specs (like altering mixture) It's still a standard engine.
5) Drive sprockets can be changed, but not the chain. Plenty of proddy people go from 525 down to 520, plus ditch the "O"ring
chains. This was common at last nationals, but not allowed under the rules. The rules are at fault, the chain should be "open"
6) "The following items must be removed or altered"
Why alter or remove the chain guard? Headlight, rear light, blinkers, horn, licence bracket MUST be removed. This should be in the "may" category. It's realistic that people could ride their bike to the track, race and go home. Removal of these items only makes it go slower, so why is it mandatory to remove them?
7) Items not allowed. This means transponders can't be used. They're not originally fitted, plus they log data. Double no no. Of course they should be OK, so this needs noting as an exception.
8) I can't find it, but in the rulebook is an age reference. The wording is wrong, from memory there are two age groups. 20 years old. Over 20. So is a 19, 18, 17, 16, 15 year old is excluded??!! A typo for sure, but needs fixing.
9) Bigger picture. The class needs a manual. Look at the fine job Karl Morgan / Ray Clee did. Good ring, good spannering.
Get these guys to sit down and write it all up. Then the new riders with little experience and support will have something to keep them safe, save them money and effectively become great riders. Having coaching courses is Ok, but is short sighted as it only gives out fish. The "manuals" way provides the fishing rods. This way the whole future, North Cape to Bluff is covered. This is the right use of SPARC money. 5k would do it.

That's it.
Thanks

[Shaun]

Hard to believe it hasnt been done - 90hp R4.5! Just pulling off a plug-cap would make it legal. The 4th `dummy' piston remains as a balancing weight as per supermono.



I can believe it has never been done as THE RULES DO NOT ALLOW FOR IT

[scracha]

BUT, cost must NEVER be a part of writing Formula-based rules, that is for the other classes. If cost reduction is a part of your decision process then you should be deciding to be in another class (now that we have the Pro Twin class)

Cost is always an issue, no matter how much money you have. For example, there's "cost restriction" measures in Motogp and World Superbike so why should a national championship in a tiny wee speck of a country be any different?

This is a small country with very small numbers involved in motorcycle road racing and very little in the way of return for riders, pit crew, sponsors, investors & manufacturers. Keeping costs below "astronomical" (i.e. just "very expensive") is the only way to increase interest and participation in the sport.

[Deano]

I just commented about making the rules, whatever they may be as I am not involved directly in the class other than trying to sort out a protest at NZSBK Rd 1 this year as riders representative, unambiguous so there is no room for interpretation.

e.g. the tyre rule; Either say what tyres are allowed specifically, or say it is open. No ambiguity then.

Cheers

Steve

So was Karl Morgan's 'oversized' rear tyre the reason for the protest ?

Has there been a determination on this yet ?

[steveyb]

So was Karl Morgan's 'oversized' rear tyre the reason for the protest ?

Has there been a determination on this yet ?

The protest made at Rd 1 of NZSBK had several points in it.
Determinations were made on most if not all of the points at the time.
As the riders representative for that meeting only I am not in a position to be able to pass further comment.
Further explanation should be sought from an official MNZ representative.

Cheers

Steve

[johnsv650]

hi steve,
the protest had two points to it, did you know that it was extended at levels and more imformation given and decision was given at invercargil, can you tell me did you get the extra information or any information after ruapuna from mnz and as the rule reads, the riders rep and the club rep vote and mnz rep only gets if a deciding vote is needed , did this happen after timaru.... ???