EVOLUTION/OEM - What Is Your Interpretation?

[BAHNZY]

Under the 2007 GCR’s for Evolution classes (and I’ve been informed that not a great deal will change, if at all in the 2008 GCR’s) there is a reference to OEM. I am interested in how various individuals interpret what OEM is. For those that don’t know the EVOLUTION GCR’s, here they are.

EVOLUTION CLASS - GENERAL
18.7.11.1 Evolution class shall be run as a national championship and can be independent of other classic Motocross classes.
18.7.12 Evolution Class- Eligibility
18.7.12.1 Bikes will be OEM.
18.7.12.2 Modifications converting later equipment to comply will not be allowed.
18.7.12.3 All components will be of the period the machine was manufactured.
a) No linkage suspension,
b) No Disc brakes,
c) Air cooled motors.
18.7.13 Evolution Class- Classes
a) Solo 125cc,
b) Solo 250cc,
c) Solo 263cc and over.
18.7.13.1 No age-group classes will be run.

Rather than ask for your specific interpretation of the actual GCR’s in isolation, I’ll give you four (4) different scenarios to ponder. Honestly I don’t think there is a right or wrong answer, but I would like to understand what iterations individuals can come up with.
 
Scenario 1
A 1980 CR250 is presented to the scrutineer at the upcoming MX Nationals in Tasmania with a set of Fox rear shocks matched to a set of FOX forks. Under the rule 18.7.12.1 “Bikes will be OEM” and given that this bike did not come from the Original Equipment Manufacturer, in this case Honda with these components, would the bike be permitted to participate?

Scenario 2
A hybrid bike has been engineered with the following components.
A stock 1980 RM250T chassis.
An XL350 engine.
The owner of this bike is considering going to Tasmania for the Nationals, is he wasting his time taking the bike?
After all the bike is using parts from the period the machine was manufactured and it is air cooled, has drum brakes and has a non linkage suspension system.

Scenario 3
A beautifully prepared 1980 YZ250 has been racing all day. From the outside the bike is as the factory built it, however beneath the skin it is a whole different ball game. The front forks have a set of emulators fitted and the rear shock is an Ohlins unit. The engine sports a late model Pro-Circuit muffler and the reed block has been swapped out for a V Force unit.
The bike/rider podiums at the Tassie Nationals and the items above are identified at the end of the days racing. What do think should be the outcome?

Scenario 4 (last but certainly not least)
The owner of a 1980 Kawasaki KX250 is patiently waiting in line to be scrutineered. The bike is 95% stock, OEM if you like, except the bike is fitted with a set of top of the line YSS shocks with adjustable everything. Should the owner be concerned about passing scrutineering?

[cyclegod]

Scenario 1... YES FOX parts are peroid mods.

Scenario 2... YES while not OEM all parts are 'of the period'

Scenario 3... NO later model pipe is a dead give away, v-force reeds are obvious but are they going to give THAT MUCH of a boost
                  as for emulators "If you cant see them, then they aren't there"

Scenario 4... YES for the same reason the Ohlins on the YZ didn't get a mention NO-ONE runs OEM shocks, except for a few garage
                  queens most VMX bikes I've seen run some kind of aftermarket shock if you can afford the best then run'em.

[All Things 414]

Scenario 5... Join VIPER, sit back, be cool....

[Maico31]

The Evolution class was introduced to the Thumper Nats in '97 with the basic rules of Air Cooled, Drum Brakes and Non Linkage Suspension to keep it simple so it wouldn't end up with all the bullshit rules and protests of the Pre 75 and similar classes. Let's hope MA don't fork with it and turn it into a complicated mess. Basically by OEM i think they are trying to say 'no later model components'. Eg.. fitting a CR480 motor into a twinshock frame. Fox forks, Ohlins shocks, etc are all elligible items from the period.

[DJRacing]

Yes I totally agree with you Maico31, a non linkage YZ '80/81 was a 465 not a 490. OEM is what the bike came out with from the manufacturer at the time of making the bike, and after-market parts (fox-ohlins) are all period stuff(for that matter any shock of any period so long as it doesnt have modern adjustments). A hybrid bike using period parts is fine because if you had the money you could have bought all the best parts available at the time to make a bike. The tough question I think that was asked is, what about the late model Pro-ciruit muffler? With the new rules about loudness, isnt fitting a newer muffler going to be what everyone is going to have to do now, or at least try to find something that will do the job of quieting down the bike but still look period? Now can someone please tell me about V-force reeds? Do they give you much more power or do the just clean up the power you have already got?
 As for the top of the line YSS shocks I believe that this goes against the bike. Top of the line YSS have high speed and low speed dampening which was never available in the day and the valving is like modern bikes. Lets remember that we are trying to recreate a period in time. One of the most important items in motocross is suspension, and by having modern valving/adjustablity isnt that a major performance inhancing improvment? Whats the difference between an aircooled motor and a watercooled motor, will I believe about the same(if not less than) period shocks to modern shocks. But we arent allowed to run watercooled??
Anyway thats my take on period racing, and YSS have very nice period shocks so there isnt any excuses as to why you have modern adjustable shocks on your bike.

[mposs]

Scenario 1  - Yes      Bike - OEM    Mods - Period

Scenario 2  - No       Bike - Under those rules No, as the bike was never manufactured in that form so  can not be OEM.

Scenario 3 - No        Bike - OEM     Mods - Not Period

Scenario 4 - No        Bike OEM      Mods - Not Period   

[Maico31]

I think with shocks, mufflers and reed blocks we have to be a bit leanient because new OEM parts are no longer easily available so we have to use aftermarket products. A new Pro Circuit muffler would be no real advantage over a new DG muffler and a new pair of hi/low speed externally adjustable shocks would perform no better than a correctly valved set of non adjustable Ohlins which were period shocks. It just means one guy can adjust his shocks in 2 mins and the other takes 2 hours. Basically it still comes down to the rider and one guy is not going to win races over another because he has a pair of trick fully adjustable shocks and a V force reed block. An RM250t with an XL350 motor would be eligible in the Evo class because he has taken a backward step in technology and not fitted later model parts and it could've been done in 1980.

[Doc]

If the new rules discrimate against hybrid bikes as in scenario 2 then MA has just shot the vintage movement in the foot bigtime. Hybrids have been around since the dawn if time so I fail to see how they could knock back a bike built entirely from era parts. I somehow feel there has been a misinterpretation as Maico31 says. I can't see why MA would change things that will detract from the numbers..doesn't make sence  

[Maico31]

That's exactly right Doc, let's hope things stay as they have been, it's been successfull so far.

[YSS]

On behalf of YSS I would like an official statement.
We only sell shocks that are within the rules.
The rules are made by MA , not us.
Europe has more strict rules and shocks can not be adjustable, even with piggyback.
We do have them shocks and they are considerable cheaper than the adjustable range.
For example pre 70  PRO or Bravos for only $250.00 a pair
 pre 75    the E 302 for $450.00 a pair  and for the Evo  with Piggybacks  the C302 are only $600.00 a pair. (YSS Australia does not stock C302 because there is no demand at the moment )
The thing is , as long as there are no rules , customers will opt for the better working Hi end shocks to get the advantage.
But should MA change the rules , what is going to happen to all the adjustable shocks that are already used ?

[oldfart]

When there is a will there is always a way around the situation  ......Lets face it most of the bike's we run are at least 27 years old , NOS is fast diminishing and this is why we are relying on after market replacements such as  YSS

[cyclegod]

I'v searched high and low and still haven't found NOS knees, back, racing spirit....

[Nathan S]

All of those bikes should be fine, even at the Nationals.

The one definite exception is if the RM/XL hybrid's engine is from a later XL350 - the Pro-Link rear one (RD to RG?) which is not eligible for Evo itself, and therefore it's bits are not Evo legal.
The V-Force in the YZ is also questionable - but AFAIK, the V-Force thing hasn't really been tested, so there's no hard-and-fast answer.

Remember that the earlier part of the manual says that rear shocks, ignitions and exhausts are (basically) free, and those components are what most of your questions relate to.
Yes, I know the rules are confusing and ambiguious, particularly WRT which pre-75 bits still apply for later bikes and which don't (tell me where it says that pre-78 bikes are exempt from the pre-75 suspension travel limits and I'll buy you a beer), but the reality is that if you've made an honest effort to follow 'the vibe' of the rules, you won't have a drama.

[DJRacing]

Walter please don't think that I am having a dig at your shocks, thats not what I am trying to say at all. It is just the way I read the rules of MA that have been posted. I personally don't care what people have on there bikes. If I cant beat them on what I am riding, then, even if I was on my modern bike I probably wouldn't beat them. I as a rider can only go so fast, and it doesn't really matter what bike I am on, its just my ability as a rider that limits me to a certain speed.
 But in the rules 18.7.12.2 and 18.7.12.3 say to me that a part has to be made in or the same as the part of the period.

My interpretation of the rules;

18.7.12.1- Bikes will be OEM.----- The bike should be correct as the manufacturer built it.

18.7.12.2- Modifications converting later equipment to comply will not be allowed.------- if the part wasn't available in that period then it isn't allowed now.

18.7.12.3- All components will be of the period the machine was manufactured.---------after market products are OK as long as they were available in the period.

Maybe MA need one more rule for when parts are hard to get or very expensive.
i.e
18.7.12.4-Non OEM bikes/parts shall not exceed the equipment of the period??

Or maybe I have it all wrong, but it does seem funny to me that we all like original nos parts (and pay the earth for them) but when it comes to racing everyone wants the latest and greatest, weather it was available back then or not. To me that is not vintage, my YZ's have yamahop because they are vintage motocross bikes and in all there wisdom Yamaha made them that way so thats how I will ride them.

On the other hand I can see why people like their modern functioning parts and as far as the rules go it would be very hard to find a complete original bike and parts of the period. For example tires, levers, sidecovers and even rims and cables. But if who ever wrote the rules wanted to be literal about them we would all be struggling to race.

[Noel]

Hi Nathan,
18.7.7.1 a,2007 GCR's
I'll have a crowny.
Apart from that As Nathan say's
 If you read the Evolution rules in conjunction with the guidelines for the  earlier classes
I think you should be alright with the YZ250 as well as the others
except the XL350 if it's from a pro link bike as I don't think they ever made a XL350 twin exhaust port RFVC with twin shocks an earlier  XL350 74/78 model would  be OK.(or just put an early XL/XR500 in)
Noel