Author Topic: Rule re-write.  (Read 46692 times)

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Offline firko

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Re: Rule re-write.
« Reply #90 on: February 10, 2014, 10:47:32 pm »
Here's some quick ideas and suggestions. As I said earlier I'm a bit tapped for time for various reasons so once I've closely read everyone elses contributions I'll hoprfully make some more additions or changes. My comments are in red (Nathans in blue)


16.15.7 Acceptable machines and components”

I believe that there are some problems with people understanding the legality of aftermarket alloy swingarms and billet triple clamps in pre 75 (and possibly other classes). It's my understanding that the only alloy swingarms available prior to 1975 were Boyd and Stellings and derivatives of their design using the same manufacturing principles, and OSSA Phantom swingarms. The generic Landrus rstyle swingarm and Thor style extruded swingarms should not be allowed in pre 75. 

I have yet to see any legitimate proof of billet alloy triple clamps being available prior to 1975. Profab cast aluminium and magnesium triple clamps should be allowed along with modern billet
replicas of them.  I think that the swingarm and triple clamp situation should be clearly spelled out in the MoMs as both swingarms and triple clamps are deemed to be  'Major components'



b) Any major component that is visually similar and operationally indistinguishable from the original will be accepted regardless of the date of manufacture. ( I am not happy with "similar" - the word "identical" is too strict for minor differences like casting changes, but "similar" is too vague. Open to input on that one!      I agree....how about  must be 'visually comparable'?


c) Any modifications to major components must be using principles and techniques that were available in the era the machine is entered in. (just stops loop-holing tactics) This is a difficult rule to enforce. How would one define “principles and techniques”? I don't understand “loop holing”.           
How about...All major modifications must be sympathetic with accepted period modifications. Dated period photographic evidence (magazine etc) may be needed for legal verification. (I know it's ambiguous and wordy but I think we need to show historic precedent.


(I killed "exhaust must follow original lines" because it achieves nothing. 

 I Absolutely  agree. This rule contradicted period fitting of up pipes to bikes originally fitted with down pipes and visa versa.


Pre 60 Solo. This class is intended to represent the formative era of motocross. (Weakly worded - needs input from the old hands). This class is intended to represent the era of motocross prior to the emergence of purpose built machines.

Pre 65 Solo. This class is intended to represent the first generation of purpose-built motocross bikes. (Again, weakly worded pre-amble - input please)    This division represents the first generation of purpose built motocross machines

Pre 70 solo. This class is intended to represent the era where 4-stroke machines lost their dominance and 2-stroke machines became dominant. This division represents to emergence of two strokes dominance of motocross.

16.15.9.10Acceptable follow on models:  AJS Stormer 250;  Greeves griffon models; Yamaha AT1, CT1, RT1 without reed valve induction. (tightening up the wording slightly) There are a lot of post 1970 machines that could be included as flow ons.....serious research needed here.

Pre 75 Solo. This class is intended to represent the last of the short travel suspension era   This division represents the last short suspension era and motocross's first boom.   \
   Acceptable follow on models pre 75:  ]As in pre 70 and other divisions, a definitive flow on list needs to be reseached.

Pre 78 Solo and Women's Pre-78. This class is intended to represent the transition era between the short travel Pre-75 machines and the long travel Evo machines.  Perfect, although I think the womens division should be in a separate section. As in the previous divisions, serious research is needed to compile an accurate  flow on list.

16.15.11.2    Front wheel travel will not exceed 229mm (9 inches) rear wheel travel will be limited to 229mm (9 inches) measured at the axle. (I want to change this to 10", but in the spirit of not changing the regs, I have resisted...) I agree with the change to 10” but also agree that it needs a separate discussion at another time.


Evolution. This class is intended to represent the era of long suspension travel, before water-cooling, disc brakes and linkage rear suspension became dominant. 
I don't believe that the Evolution class represents a particular era. Perhaps this is more in keeping of the concept.......”The Evolution division is a technology oriented class for machines with air cooling, drum brakes and non linkaged suspension”.

Because I'm not involved with or up to speed on the eligibility criteria of any post Evo classes I have deliberately stayed away from contributing any thoughts or ideas.  









« Last Edit: February 11, 2014, 10:05:13 am by firko »
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline firko

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Re: Rule re-write.
« Reply #91 on: February 10, 2014, 11:08:56 pm »
Quote
Your bike is an oddity, in that it was one of two/three 'production' bikes with more than 4" of rear travel - in some ways, I'd say that it's proper home is the Pre-78 class, being the "transition era"... The existing rules prohibit you from entering your 1974 model bike in Pre-78, though...
For what it's worth in this discussion, the following bikes had more than 4" of rear travel in 1974...
Maico, KTM, Yamaha YZ/B, CCM, AJS Stormer, Kramer and (anecdotally, and if so, ever so slightly) Husqvarna and Montesa.
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline FourstrokeForever

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Re: Rule re-write.
« Reply #92 on: February 11, 2014, 08:18:38 am »
Quote
Your bike is an oddity, in that it was one of two/three 'production' bikes with more than 4" of rear travel - in some ways, I'd say that it's proper home is the Pre-78 class, being the "transition era"... The existing rules prohibit you from entering your 1974 model bike in Pre-78, though...
For what it's worth in this discussion, the following bikes had more than 4" of rear travel in 1974...
Maico, KTM, Yamaha YZ/B, CCM, AJS Stormer, Kramer and (anecdotally, and if so, ever so slightly) Husqvarna and Montesa.

I still think that those mentioned bikes that were produced with more than 4" of rear travel should be accepted as eligible for pre75 with their original rear travel without forcing people to modify their bike(s) to have less travel. At the end of the day, 1" more travel isn't going to make a great deal of difference IF, and only IF, the bike was manufactured that way.
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Offline yamaico

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Re: Rule re-write.
« Reply #93 on: February 11, 2014, 09:01:38 am »
I have previously - and still do - agree with Mr Slakewell on the suspension travel limits - and have to ask why this area gets picked out as being limited to fall into an era when the bike resides.  yes I have a YZB - it is pre 75 but it is bought back to the field because it was ahead of everybody else - why?  It seems to impact more on pre-78 than pre 75 but as mentioned eras are used to sort groups and if a particular bike falls into that category why penalise it.  Surely there is enough knowledge around that we could leave the statement that suspension must not exceed OEM specs or similar or the maximum for a particular bike in an era  Ie pre 75 could be maxed out at whatever the YZB was?? 

I see previously lots of comments about this - particularly with pre 78 yet seems the normal commentators on this are absent currently?

I do agree Ross. If a certain model bike had more suspension travel as standard before December 31/1974, then I don't think it should be restricted to suit the 7" and 4" rule. It is actually backward engineering the original bike. Maybe there should be some exceptions to the rule rather than allowing all pre75 machines to have 5" rear suspension travel....

This will open the floodgates for LTR conversions on every radial Maico.

Offline GMC

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Re: Rule re-write.
« Reply #94 on: February 11, 2014, 09:20:59 am »
Focus guys, focus.

I’m normally in favour of thread hijacks but talking about travel restrictions or any other rule deviation will just bog this thread down with a heap of crap again.

The purpose here is to improve the wording which people have been complaining about for decades and I believe if too many changes are added in the same proposal then the whole lot will be thrown out the window.

If you want to debate water cooling in Evo or 10” travel for pre 75 then start another thread.
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Offline firko

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Re: Rule re-write.
« Reply #95 on: February 11, 2014, 09:45:32 am »
Quote
Focus guys, focus.
I’m normally in favour of thread hijacks but talking about travel restrictions or any other rule deviation will just bog this thread down with a heap of crap again.
The purpose here is to improve the wording which people have been complaining about for decades and I believe if too many changes are added in the same proposal then the whole lot will be thrown out the window.
If you want to debate water cooling in Evo or 10” travel for pre 75 then start another thread
I agree Geoff, Nathans already stated that it's not the intention of the thread to change the rules, only to make the wording more user friendly. I only made my list in reference to a previous post and to let folks know that it's not just the Yamaha and Maico that have more travel.
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline FourstrokeForever

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Re: Rule re-write.
« Reply #96 on: February 11, 2014, 10:11:00 am »
Quote
Focus guys, focus.
I’m normally in favour of thread hijacks but talking about travel restrictions or any other rule deviation will just bog this thread down with a heap of crap again.
The purpose here is to improve the wording which people have been complaining about for decades and I believe if too many changes are added in the same proposal then the whole lot will be thrown out the window.
If you want to debate water cooling in Evo or 10” travel for pre 75 then start another thread
I agree Geoff, Nathans already stated that it's not the intention of the thread to change the rules, only to make the wording more user friendly. I only made my list in reference to a previous post and to let folks know that it's not just the Yamaha and Maico that have more travel.

Fair enough statements guys. I was just thinking of adding something along the lines of some exceptions to the pre75 7 and 4 rule for bikes that came standard with a bit more travel. Afterall, they raced back in the day with their original configuration without restriction.
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Offline firko

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Re: Rule re-write.
« Reply #97 on: February 11, 2014, 11:39:34 am »
I think we're now well on the way to sorting the MoMs wording and interpretation out. From what I can see there are some classes that need little or no modifications to their wording or rules. One problem that is appearing more and more however is the use of trick 'billet' or custom made aftermarket parts manufactured in the USA and elsewhere. Many people seem to think that if a part is allowed in AHRMA competition it must automatically be allowed here. At the risk of repeating my point, alloy billet triple clamps might well be legal for pre 75 in AHRMA competition but they are not legal under our MoMs. This is also seen in the number of KLR or Thor style swingarms appearing on Australian pre 75 bikes, their riders assuming them to be legal when in fact they aren't according to the MoMs definition of 'Major Component' and  period integrity.
*Pre 75 has traditionally been the sports most popular class and needs nothing other than some minor wording changes and parts eligibility criteria detail added (eligible aftermarket  'Major Components' (aftermarket frames, swingarms and triple clamps, see Reply #93 ).

*Pre 78 seems to be the class most in need of a definition tune up. The rules for the class were originally 'borrowed' almost to the word from the AHRMA rule book and it's since shown that they hold some inherent flaws . The biggest problem seems to be in suspension limits, many racers believing that the current 9" limit is inadequate. I believe that the suspension limit needs to be adjusted to that of the longest OEM travel bike in the class, whether that be 10", 11" or whatever. It's easier to put an inch of travel into a bike than to de-engineer it to a lower limit (9"). Another situation that seems to be worth investigating is to remove the "standard suspension mounting points" stipulation. Once again, harking to my earlier post, there wasn't another era except maybe for pre 65 where bikes were modified more for increased performance. The suspension revolution was in full swing in the '75-'78, with all sorts of frame and swingarm mods being commonplace. A lot of guys were still racing their '74 (and earlier) bikes with upgraded suspension mods, I myself had a Montesa 360 with Maico style rear suspension and Marzocchi forks.
I'd suggest removing any reference to suspension mounting points from the pre '78 regs.

Evolution. DJ's on the money with his ideas (Reply #82 ). The beauty of Evo is in its simplicity and lack of overbearing eligibility rules, it's the poster child for the KISS principle. For that reason lets not over complicate it with too many words. Here's my version....
*Evolution class machines must be air cooled, have drum brakes and non linkaged suspension.
*All major components must have been derived from an air cooled, drum braked and non linkaged motorcycle.
*Parts from any bike that is water cooled, disc braked or featuring linkaged suspension are not allowed.
* There are no suspension travel limits in Evolution.


Another challenge is to create a fair eligibility list for pre '60 and pre '65. These classes are undergoing a small but inspiring resurgence in interest and I feel that to make the classes as accessible as possible we need to broaden their eligibility criteria. I make reference to the BSA B40 distributor/points models grey area for pre 65 and acceptance of modern Indian manufactured Royal Enfields as a cheap and readily available machine for both pre '60 and/or pre 65 as examples of some points that need to be addressed. There needs to be a serious discussion and research into allowing as many machines into both classes without infecting the historic integrity of the class(es).

A similar research undertaking is needed to compile a list of eligible flow on models for all classes with the exception of Evo. There are already some listed flow ons for pre 70 and pre 75 but I feel that there are more machines that could be allowed for those classes and that a similar list be created for pre '78, pre 85 and pre 90. I propose that volunteer committees of knowledgeable people should be formed to consider flow on alternatives for all eras. There are some very knowledgeable and passionate people (many of them frequenting this forum) interested in the various divisions that I feel could really make a contribution. 
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline sa63

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Re: Rule re-write.
« Reply #98 on: February 11, 2014, 02:55:37 pm »
where do (newly made) EVO shocks with clickers fit into the above proposals - surely these are as major a component as forks?
There aren't enough old shocks left to use.. and improved parts are now made ,so the wording should also incorporate newly made items rather than a flat statement about the origin of the part being from a non linkage bike.
But then I agree with DTs statement about any original drum brake front end being ok, especially as new shocks are way more sophisticated than any pre85 drum brake front end..


Offline firko

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Re: Rule re-write.
« Reply #99 on: February 11, 2014, 03:20:03 pm »
Shocks aren't regarded as major components mainly because they are an often replaced item. There are arguments for and against external clickers being allowed in some classes, especially pre 75 but it's been proven beyond doubt that stacked shim shocks with external dampening adjustment existed in 1973. The fork situation raised by DT isn't in essence a bad idea, it's more the timing of his announcement that any drum braked front end can be used being so close to the Nats that causes the controversy.
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline Brian Watson

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Re: Rule re-write.
« Reply #100 on: February 11, 2014, 04:11:56 pm »
The biggest problem seems to be in suspension limits, many racers believing that the current 9" limit is inadequate. I believe that the suspension limit needs to be adjusted to that of the longest OEM travel bike in the class, whether that be 10", 11" or whatever. It's easier to put an inch of travel into a bike than to de-engineer it to a lower limit (9"). ..........From post #100..I would have trouble with this.. to re-engineer a set of forks that had 9 in of travel to 11 in (or whatever travel is the longest) is asking for trouble..the amount of overlap in a 9 in set of forks would not (safely) allow you to extent the travel to 11 in..  much, much easier to reduce the travel than to add some in.. to reduce all you need to do is to add a spacer or add a longer rebound spring onto the damper rod.... to add travel you need to extend the damper rod....

Offline firko

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Re: Rule re-write.
« Reply #101 on: February 11, 2014, 04:24:15 pm »
True, I wasn't thinking of modifying damper rods, I was thinking more along the lines of changing the forks as a unit. Point taken though.
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline Ted

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Re: Rule re-write.
« Reply #102 on: February 11, 2014, 06:20:24 pm »
Mark, where are you getting your suspension theories from

1- Where do you get a pair of 36 mm forks manufactured before 1/1/78 from that will allow eleven inches of travel

2- The amount of flex alone with that much travel would be bordering on dangerous.

3- It is far cheaper and easier to reduce travel than increase it

I suggest you take a pair of shocks to a suspension guy and get a quote on putting a two inch increase into them and then get a quote on reducing them by the same margin. You will change your view then


The biggest problem seems to be in suspension limits, many racers believing that the current 9" limit is inadequate. I believe that the suspension limit needs to be adjusted to that of the longest OEM travel bike in the class, whether that be 10", 11" or whatever. It's easier to put an inch of travel into a bike than to de-engineer it to a lower limit (9"). ..........From post #100..I would have trouble with this.. to re-engineer a set of forks that had 9 in of travel to 11 in (or whatever travel is the longest) is asking for trouble..the amount of overlap in a 9 in set of forks would not (safely) allow you to extent the travel to 11 in..  much, much easier to reduce the travel than to add some in.. to reduce all you need to do is to add a spacer or add a longer rebound spring onto the damper rod.... to add travel you need to extend the damper rod....


To get 50 mm more travel out of Pre 78 forks you would have to use longer staunchions as well as longer sliders, say off a T model. Which is illegal.

The 9 inch rule was in long before these guys with 11 inch travel started racing VMX. They were well aware of the limit. Do what Scrivo did, change it to nine inches. He's not complaining.
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Offline Rossvickicampbell

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Re: Rule re-write.
« Reply #103 on: February 11, 2014, 07:18:19 pm »
Teed - that is incorrect isn't it - travel longer than 9 inches - be it whatever it is - was certainly in for pre-78 - hence the questions being asked about the limitation?
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Offline Ted

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Re: Rule re-write.
« Reply #104 on: February 11, 2014, 07:45:25 pm »
All right, then you answer the question then. Where are you going to get forks from that will have 11 inches travel in 35, 36 mm diameter manufactured before 1/1/1978

Every one is up in arms now because they can't buy Evo legal H forks and  TLS hubs. How many 35 / 36 mm forks are out there with 11 inches of travel. You can say 250 and open have 38 mm forks, but if you make it 11 inches for Pre 78 you have to include all capacities.

A good brand, well set up shock at 9 inches will easily out perform a cheap shit shock at what ever length you care to make it.

To be quite honest I hope it comes in, everybody has 11 inches in Pre 78. I for one will be leaving mine at 9 inches. It's not rocket science why 8)
« Last Edit: February 11, 2014, 07:48:28 pm by Ted »
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