What flatslides are legal for Pre 85?

[Nathan S]

Well sod it then: I may as well run my 2013 Beta in Pre-85 because there was water cooling, double discs and Keihin flatslides in 1984 too...

My "agenda" is to be a part of a sport that has a reason for existing, and have rules that both support those reasons and can be enforced.
Makes me wonder what sort of agendas are offended by this...

By the way, this is from the 2015 MoMS, downloaded 10:29am this morning:

16.11.1.2
The onus of proof of eligibility shall rest
wholly upon the rider or entrant of the
machine. Service and parts manual
publication dates are not proof of eligibility.

[Nathan S]

How the hell it is irrelevant Nathan is beyond me. I have proven that the part in question, A PJ Keihin flatslide carby was indeed available prior to the 30/12/1984 cut off date for pre85 machines. Just because it is different to what was on the CR500RE at the time IS IRRELEVANT. A VM Mikuni or Lectron didn't come out on the said bike either. You argue your own arguments.
Thank christ you're not an eligibility scrutineer or we would all be stuck with stock standard bikes. Something which NEVER happened in the day.

The key point is that the component in question, a Keihin flat slide carb, was readily available in 1984.

Anyone could have bought a CR250F carb from a Honda dealer late in 1984 and fitted it to a 500RE.

And that Nathan, IS THE RELEVANT POINT.

No more from me. I'm tired of trying to make a clear and concise point with a know it all.....

This discussion is annoying you, because you are wrong. This is not a matter of opinion, you are trying to dispute some of the clearest and least ambiguous parts of the CMX regs.

Here are the current regs, with the relevant bits in bold:

16.15.13 Acceptable machines and components: Pre 85 Solo

16.15.13.1 Acceptable for the pre 85 class are machines and components built up to and including the 1984 model. The only exception to this rule is where the model remains unaltered after this date.

16.15.13.2 Carburettors; period flat slide carburettors and any round slide carburettor may be used.

16.15.13.3 Engines and gearboxes must remain externally unchanged.

[16.15.13.4] All machines will be fitted with an effective muffler and comply with sound control regulations in GCR 16.12.

16.15.13.5 Folding footrests must be fitted.

16.15.13.6 Countershaft sprocket covers will be fitted.

16.15.13.7 The handlebars must be equipped with a protection pad on the cross bar.
Handlebars not fitted with a cross bar must be equipped with a protection pad located in the middle of the handlebars covering the handlebar clamps.

It is really very simple: If the 85 model PJ is not "unaltered" from the 1984 model part, then is does not meet the rules. Simple as that, and no amount of calling me names will change that.

Its not about making people run stock bikes. Its about making sure people are using parts that existed in 1984.

Edit for FireKwaka:
The part about the exhaust 'following original lines' was removed for 2015. Rest easy.

[Rossvickicampbell]

and you could never buy RC parts from your local Honda dealer either that I am aware of?

[KTM47]

So....we just need a part listing dated 1984?   Bugger this, I have found a Mikuni VM, can someone please tell me the setup for a 83 KX500?   NOW the pipe drama, when I first built my bike there were no pipes to be found (GMC) wasn't making them then. After spending over 12 months to design, build and modify a chamber that was finally rideable I would be very dark if someone protested that it doesn't follow original lines!!! Neither did downpipes but they were used in the day on post classics.

That rule no longer exists in the 2015 MOMS.  The facts are the old rule was not being enforced.  eg 1977 Maicos with wheelsmith pipes and any Dirt Track bike with a down pipe instead of the standard pipe.

[LWC82PE]

The way i look at it is for any given year cut off based class you can use any period aftermarket/accessory parts (if you can prove you could buy it back in the day then) that were available up until yr cut off. In this case anything you could walk into a shop and buy up to dec 31 1984. Now there are exceptions of course for some classes eg period water cooled heads in Pre 78 which are not allowed but were available.
But when it comes to OEM parts, its a bit different, and you cant use any OEM parts off a 1985 model, even if you could buy that model late in 1984.
If you could buy these Keihin flat slides as an aftermarket part in late 84 then they would be allowed, but from what i am reading they were only available as a Honda OEM part originally intended for a 1985 model bike so it seems pretty logical to me that they are not allowed, otherwise almost all parts from a 1985 model bike would be allowed in pre 85 as you could buy the 1985 models in 1984. If the Keihin is allowed in pre 85 then so would 1985 RM-F disc front ends as you could buy a 85 RM in late 84 but thats not how the rules work.

So a simple way to look at it is for pre 85 racing

you can use any period aftermarket part available up 31/12/84
you can use any any OEM part from from a 1984 model bike but not from a 1985 model bike.

[Nathan S]

and you could never buy RC parts from your local Honda dealer either that I am aware of?

According to what the rules say, there's no restriction on Works parts. If there's been a proper MA determination on this matter, I'd be interested to hear the details.

There was no restriction on works parts/bikes competing in modern MX, or any form of production rule. It would seem odd to retrospectively turn VMX into a production bike class, particularly when we have specifically welcomed and even encouraged custom, low volume parts over the history of VMX.

Add in the difficulty of writing and enforcing rules that kick out true "works parts" without also kicking out the rare aftermarket stuff and/or GMC's CZ frames*, and I can't help but think that the "no works parts" rule doesn't really exist (regardless of any previous advice).

*The GMC HL500 frames are OK, because Evo class stuff can be unashamedly 2015 model.

[KTM47]

It has already been established courtesy of that post showing the period French language magazine article that  HRC 500 cc motocrossers used Keihin flat slide carbies identical to production items (presumably those destined for the CR250).

In other words you could buy a 500RC carby from your local Honda dealer.

All this shows is that the carby was for a 1985 model bike and therefore not eligible for Pre 85.  Even if the carby was available from a Honda dealer late 1984 it would be as a spare part for a 1985 model bike.

So anything that is a spare part for a 1985 model bike should not be considered eligible (in my opinion).

[Hardo]

I'm with Nathan here. Well not with him, but you get the idea ... 

The way I read  ' components built up to and including the 1984 model ' doesn't mean "parts available in 1984" or "parts available up to 31Dec 1984" at all.

It means components built up to and including the 1984 model ! ie: parts that were actually available late 1983 !

Thats how I read it anyway....... but I'm just a dumb Aircraft mechanic..... 

[FireKwaka]

Fair enough that parts for 85 models shouldn't be allowed however I am still clinging to the 84 CR500 ran a standard PJ. If someone showed up with such a bike would they be turned away or protested, I should hope not.

[Ted]

I'm with Nathan here. Well not with him, but you get the idea ... 

The way I read  ' components built up to and including the 1984 model ' doesn't mean "parts available in 1984" or "parts available up to 31Dec 1984" at all.

It means components built up to and including the 1984 model ! ie: parts that were actually available late 1983 !

Thats how I read it anyway....... but I'm just a dumb Aircraft mechanic..... 

Hey Roger imagine if someone actually fully restored a beautiful 1985 CR 250 to ride in Pre 85. Now that would be one really dumb mutha forka I crack myself up

[John Orchard]

So what we are saying is, you can't use an RM125C alloy swingarm on an RM125B in Pre 78 ?  ;-)  lol

[Ted]

So what we are saying is, you can't use an RM125C alloy swingarm on an RM125B in Pre 78 ?  ;-)  lol

Correct? Also can't use the rubber mounted bars, pivoting brake stay arm etc.

[Nathan S]

Fair enough that parts for 85 models shouldn't be allowed however I am still clinging to the 84 CR500 ran a standard PJ. If someone showed up with such a bike would they be turned away or protested, I should hope not.

They would be promoted to the Pre-90 class.

And the 1984 Honda CR500RE did not come with a Keihin PJ carb standard. It came with a Keihin PE roundslide.

http://www.mrcycles.com/oemparts/a/hon/506bdd66f870023420a27bd6/carburetor

[FireKwaka]

Another typo, I meant RC500

[Nathan S]

Another typo, I meant RC500

Ok, then that's up to you to prove - and "they look pretty much the same" isn't enough.

Like I said, if you can prove that the 84 RC500 carbs are the same as the 85 production PJs, then I will be happy to reverse my position.