The cheater MX85 argument. I might be changing my mind.

[husaberg]

I actually almost agree,

10% oversizes.
I think that gives enough fair options to everyone.
(I have to say I never really agreed with the over sizes given to the 150cc 4T. Anyone serious will take the hit and bore to maximum oversize anyway. sleeves are cheap).

but I'd be keeping the:

Non competition derived engine, including the following:
transmission, blablabla.
125cc 2t 24mm Carb Restriction (10% max oversize). Aircooled
180cc 2valve 4Ts (10% max oversize). Aircooled

if you want to run watercooled engines (or competition derived engines or components), you have to run the smaller size.
Exception of Pistons...
Thermal constraint will level the playing field during a race; and it will make things interesting tactically during longer events...

what are you thinking re the restriction on a LC125? or just only to 100cc?

and the parts what of the parts

[Bert]

what are you thinking re the restriction on a LC125? or just only to 100cc?

and the parts what of the parts

na.
no LC125's...
Everyone have been crying about 85cc, why would you allow a LC125??
Name a common LC125 engine?
(I"ll start: Aprillia RS125 - not common)...
maybe this conversation should be in another tread....

Parts.
What parts? Same rules as current; no need to change anything with the current configuration.
might as well keep the baby and some of the bath water...


Same rules as current with the extension for:
10% oversize.
I think that gives enough fair options to everyone.

but I'd be keeping the:

MX engines, limited to 85cc no other restrictions

Non competition derived engine,
Following components (MUST NOT BE DERIVED FROM A COMPETITION ENGINE):
transmission, blablabla.. (same as last 10-25years)
Open:
Pistons, pipes, ignition..blabla...(same as last 10-25year)

[B]100cc 2t (Max 10% oversize). Water or Aircooled
125cc 2t 24mm Carb Restriction (10% max oversize). Aircooled only
150cc 4 valve 4Ts (10% max oversize) Water or Aircooled
180cc 2valve 4Ts (10% max oversize). Aircooled only

if you want to run watercooled engines (or competition derived engines or components), you have to run the smaller size.

The whole thing has been about fair modification and potential ramifications of introducing MX85 engines into the current class.
Thermal constraint will level the playing field during a race; and it will make things interesting tactically during longer events...

[Yow Ling]

Dont worry we are onto it.

[husaberg]

na.
no LC125's...
everyone have been crying about 85cc, why would you allow a LC125??

Parts.
What parts? Same rules as current; no need to change anything with the current configuration.
might as well keep the baby and some of the bath water...


Same rules as current with the extension for:
10% oversize across the board,
180cc 2Valve 4T

and entry of 85cc...

OK so let me get this clear on one hand We want to let in MX85 so people can have cheap access to available engines that have cheap high quality parts........
BUT
For the current legal bikes... Hell no they are no allowed to use the same bearing and conrods even though they are cheaper better and more available............. it seems like a silly idea to me..........like getting this guy to babysit your kids........

[Bert]

OK so let me get this clear on one hand We want to let in MX85 so people can have cheap access to available engines that have cheap high quality parts........
BUT
For the current legal bikes... Hell no they are no allowed to use the same bearing and conrods even though they are cheaper better and more available............. it seems like a silly idea to me..........

Different conversation; different set of rules & considerations Husa - start a new tread and seek feedback?

Personally, I don't really see a problem with the current mainstream compliant engines and availability of quality parts and equal of less that the MX85 parts (as Rob has already pointed out).
Ok. I've been caught out on my "parts are cheap; thus let them in statement"///

yes I'll admit that the number of suppliers are limited - conversation and exploration into this issue is needed...


One off specials... well that's life...


a MX85 will likely need to be cheaper for parts... different conversation...

[Henk]

My biggest objection to this concept all along is that if we allow 85mxers we should have a long hard look at the parts anyway. If an 85 can have the dirt bike gearbox why shouldn't something else.

The thing that has me questioning it now is that by all accounts bugger all people would build one anyway, it isn't going to be the saviour of a class that seems to be gaining numbers at the moment anyway, as it has been for the past five years or so that I have been involved.
If this was to be introduced I'd suggest leaving everything else alone and limiting it by capacity only, anything else is too hard to enforce.
The other concept I've heard mentioned lately is to allow 125 MX engines, possibly as an F4.1, in some ways that makes more sense to me but opens another huge can of worms.

[husaberg]

Different conversation; different set of rules & considerations Husa - start a new tread and seek feedback?

Personally, I don't really see a problem with the current mainstream engines and availability of quality parts and equal of less that the MX85 parts (as Rob has already pointed out).

One off specials... well that's life...


a MX85 will likely need to be cheaper for parts... different conversation...

No... no.... no... Brent same conversation, same issue, same thread, for the reasons i spelled out above, opening up to Mx85's makes the current rules untenable......
Brent for instance in F4 and F5 it is against the rules to use a CR125 conrod, which is nearly a swap for a MB100 and has a silver plated bearing.
it is cheaper better anss designed for high speed use so safer.....

For my build i had to hunt extra long for the rod length (i wanted to use) and stay legal i could have just used a MX one... far far cheaper and easier to get.
yet a MX85 can use a mx rod and bearing. Am i the only one to see an issue here.
I am only talking bearings conrods clutches cranks and so forth, not cylinders, heads.......

[chrisc]

[B]100cc 2t (Max 10% oversize). Water or Aircooled
125cc 2t 24mm Carb Restriction (10% max oversize). Aircooled only
150cc 4 valve 4Ts (10% max oversize) Water or Aircooled
180cc 2valve 4Ts (10% max oversize). Aircooled only

Bert, the bold bit above should be deleted. Like the current rules, the cooling restriction applies to 125 2t. This specifically states air cooling which excludes any other type of cooling including oil cooling.

If the above rules were run, FXRs would be illegal as they are oil cooled. Best to just exclude any mention of cooling except for 125 2t (aircooled only) and for 180cc 2V 4Ts (aircooled only), like so:

100cc 2t (Max 10% oversize).
125cc 2t 24mm Carb Restriction (10% max oversize). Air cooled only
150cc 4 valve 4Ts (10% max oversize)
180cc 2valve 4Ts (10% max oversize). Air cooled only

[goose8]

My biggest objection to this concept all along is that if we allow 85mxers we should have a long hard look at the parts anyway. If an 85 can have the dirt bike gearbox why shouldn't something else.

The thing that has me questioning it now is that by all accounts bugger all people would build one anyway, it isn't going to be the saviour of a class that seems to be gaining numbers at the moment anyway, as it has been for the past five years or so that I have been involved.
If this was to be introduced I'd suggest leaving everything else alone and limiting it by capacity only, anything else is too hard to enforce.
The other concept I've heard mentioned lately is to allow 125 MX engines, possibly as an F4.1, in some ways that makes more sense to me but opens another huge can of worms.

Sounds good mx125 motors open but only on kart tracks would be heaps of fun big high sides would be the norm. But it would be a awesome ride I'm keen as

[Bert]

No... no.... no... Brent same conversation, same issue, same thread, for the reasons i spelled out above, opening up to Mx85's makes the current rules untenable......
Brent for instance in F4 and F5 it is against the rules to use a CR125 conrod, which is nearly a swap for a MB100 and has a silver plated bearing.
it is cheaper better anss designed for high speed use so safer.....

Not untenable, maybe compromised...
Yes those lucky Suzuki and Yamaha engine builders have seen the merge of MX vs. non-MX rod kits (and bearings) in many cases. Or have plenty of road convertible options.

I'm assuming you state safer due to the longer life span...
Rather than builder pushing capabilities of engines as a whole..
That is part of the art of tuning as well; building with in capabilities.

But I'm actually on the fence on this topic (directly related to the fact above).
So my view is that is is a topic for another discussion and proposal.

Transmission nope.. And I mean gearbox (just to be clear)..

Bert, the bold bit above should be deleted. Like the current rules, the cooling restriction applies to 125 2t. This specifically states air cooling which excludes any other type of cooling including oil cooling.

If the above rules were run, FXRs would be illegal as they are oil cooled. Best to just exclude any mention of cooling except for 125 2t (aircooled only) and for 180cc 2V 4Ts (aircooled only), like so:

100cc 2t (Max 10% oversize).
125cc 2t 24mm Carb Restriction (10% max oversize). Air cooled only
150cc 4 valve 4Ts (10% max oversize)
180cc 2valve 4Ts (10% max oversize). Air cooled only

Very valid point Chris.

For my build i had to hunt extra long for the rod length (i wanted to use) and stay legal i could have just used a MX one... far far cheaper and easier to get.
yet a MX85 can use a mx rod and bearing. Am i the only one to see an issue here.
I am only talking bearings conrods clutches cranks and so forth, not cylinders, heads.......

Specials. Bum, those of us that have tried to build a special know the issues... As per comments above I do sit on the fence (and it would make my tz100 build easier, but I'm not sure if it would make it any cheaper)...

But.... Seems as it's likely to carry on in this thread: let's drive in a little further...
Maybe some of the wording in the rules should be modified (falling in line with other classes) around homologation of sorts. Maybe we shouldn't allow in engines that are not actually available in good numbers here in NZ.
It solves the conversation around issues of parts availability or checkbook racing...
Yes that change would remove my old ball (somewhat unattainable out unless in Europe /UK/Japan) from the mix... But that may be for the betterment of the class (not that I win anything)..
It would also close the door on the purchase of "road" noncomp bore up kits for 50cc....

But why the view of open clutches?
And that is a serious question, it something I've never really considered..

[husaberg]

Not untenable, maybe compromised...
Yes those lucky Suzuki and Yamaha engine builders have seen the merge of MX vs. non-MX rod kits (and bearings) in many cases. Or have plenty of road convertible options.

I'm assuming you state safer due to the longer life span...

No safer due to durablity my father still limps from a rod letting go in 1986........

Rather than builder pushing capabilities of engines as a whole..
That is part of the art of tuning as well; building with in capabilities.

Brent this agrument has been used to let in the MX85's
So its untenable because it is on one hand saying open it up to allow competition engines, cause it will be cheaper, more freely available, then on the other saying no stay the same for the rest.......

So my view is that is is a topic for another discussion and proposal.

If the rules are to be changing the this stuff has to be sorted first because it is part of the same reasoning

Transmission nope.. And I mean gearbox (just to be clear)..

But the clutch is part of the transmission is it not.
Which makes STD MX clutch plate illegal.
Remember Robs want to convert his basket from the silly inside out springs held by pins he could have used a basket or pressure plate of a 79 RM125 but couldn't cause they are against the rules. he couldn't use the OEM MX plates either.....
STD OEM plates of a CR80 are better than MB100 as they are pulp not paper... again illegal......Yeah while i am sure he might be able to find some obscure model that would suit and maybe find in the EBC catalog that they list the plates for both but why should he have too if the MX85 goes in for being more available and cheaper why not fix the reasons that some of the other stuff is not as freely available and cheaper

Specials. Bum, those of us that have tried to build a special know the issues... As per comments above I do sit on the fence (and it would make my tz100 build easier, but I'm not sure if it would make it any cheaper)...

But.... Seems as it's likely to carry on in this thread: let's drive in a little further...
Maybe some of the wording in the rules should be modified (falling in line with other classes) around homologation of sorts. Maybe we shouldn't allow in engines that are not actually available in good numbers here in NZ.
It solves the conversation around issues of parts availability or checkbook racing...
..
Yes that change would remove my old ball (somewhat unattainable out unless in Europe /UK/Japan) from the mix... But that may be for the betterment of the class (not that I win anything)..
It would also close the door on the purchase of "road" noncomp bore up kits for 50cc....

Not really.. should mine and Brens NSR125 based builds be banned cause gee that would keep the racing cheaper for me or you who have invested already a fair bit of money..where to draw the line....i have no real issue with the euro kits being used

But why the view of open clutches?
And that is a serious question, it something I've never really considered..

the clutchs well it was about the plates MX ok Honda RS125 or similar not allowed.
Not that it maters as i can get a legal dry clutch anyway ..imagine the hater if someone turned up with one of those........

I should point out when i say illegal it is by most people interpretation of the rules

[Bert]

Ok. Some validly to your views. Maybe just clears up that side of the coin.

Well, I might swing back to the na leave everything as it is: side of the fence (for a a little bit longer).
Personally there are plenty of options available currently and the current rules are open enough to encourage those that investigate options plenty of performance solutions without breaking the rules.

The rules work and parts are available.
And under the current scheme there isn't any option of entry of a subclass (MX85) into the rules with isolating the current active riders or exposing the current active rules to extra modification...
The last thing I would want to do is compromise or isolate those people actively involved in the class or organising events.

So no addition of the 10% oversize or 180cc two valve...

It's not fair argument & what's in it for me; just keeps coming up as a wall for moving forward logically.

Like others already, the point of arguing the toss about 85cc is a waste of energy; if they can't be treated as a separate conversation..
I have a legal two and four stroke; so it makes no difference to me... Both far outweigh my capabilities, so there isn't anything in this (read introduction of MX85 or modification to the current rules) for me.
Plus I've got all the good bits I need to keep them going for a long time, maybe even enough that I might get to the stage that I can actually benefit from what I've built.. But that's going to take a long time.

[TZ350]

Am i the only one to see an issue here.
I am only talking bearings conrods clutches cranks and so forth, not cylinders, heads.......

No your not the only one, I just don't know what the answer could be.

[jasonu]

na.

Name a common LC125 engine?
...

Not common by any means but if the LC125 rule came in then Ke125 bottom end with an RG500 cylinder. I think it will pretty much bolt right on to my motor. It has better everything.

[jasonu]

Different conversation; different set of rules & considerations Husa - start a new tread and seek feedback?
a MX85 will likely need to be cheaper for parts... different conversation...

No I think this is the perfect place to discuss these points. If MX85's are allowed in these are the sorts of issues that can and will arise and now is the time to hash them out BEFORE the rules are changed.