did we ever come to a conclusion about the alloy swingarm for the pre'78 RM125's

[Brian Watson]

I am certain that Mikkola used GG's in 1974...you can see the test of one of his bikes in the book "The Big Leap" ...by 1976 when he was completing in the 250 GP's ....well maybe Ohlins by then...but ...HVA were still using GG on the production bikes until 1978....even then the Ohlins only appeared on the 390's....sorry about the hijack..

[motomaniac]

I am certain that Mikkola used GG's in 1974...you can see the test of one of his bikes in the book "The Big Leap" ...by 1976 when he was completing in the 250 GP's ....well maybe Ohlins by then...but ...HVA were still using GG on the production bikes until 1978....even then the Ohlins only appeared on the 390's....sorry about the hijack..

Yer but Mikkola won in 76 so if he was using Ohlins they wouldn't say that Moiseev was the first worldchamp to use.For sure Mikkola wasn't using the GG's from the previous years in 76 .What ever they were they don't look like GG's .  Haha ..hijack ?what Hijack ? Have you read some of the other theads? At least we are not looking for spelling and punctuation mistakes

[Husky500evo]

      I think that a thread hijack is ok when the thread is 9 pages long & the subject has probably ground to a halt anyway. At least the hijack is related to vintage motocross (which is what this forum is supposed to be about), not road racing or sidecars  . On the original subject of the thread , I think you would have to feel hard done by if you turned up with alloy O.E.M Suzuki swingarm (even if it was off a C model & had the lug welded on in the right spot) on your RM125B & a parts manual from early '77 showing it as an option, only to have it knocked back .
       I am still scratching my head about TM Bill's trivia question about if there were any '77 models that came out standard with an alloy swingarm . I can't think of any , but I wouldn't be surprised if something exotic came out with one . I know that the '74 Ossa Phantom came with an alloy arm, but I think that they went back to steel on later models .   

[trailietrash]

16.4.0.9 Major components that were manufactured
         outside a specific period, but which are
         visually indistinguishable from period
         components shall be eligible for that period.

If I read the rule above as it is written and apply it to the photo of the swingarm on the first page of this never ending debacle I would have to answer your question Doc with .......... Yes ................it should be allowed. The swingarm was available "in the period" so even if it was manufactured after 77 it should be allowed as it has been shown to be a period component in both parts books prior to 78 and also in publications.

The MOMS do say that  "Service and Parts Manual publication dates are not proof of eligibility." But the MOMS do not say that these publications cannot be used to establish a year of manufacture of a major component, more just that the existence of parts and service manuals does not automatically mean that parts listed in a publication are acceptable for competition in a certain period.

But, I guess, It will take a scruitineer to accept a competitor to compete with this style of swingarm in both belief and evidence that the component is acceptable for the period and another competitor to protest its use to really sort this out. What a shame for a sport that is meant to be both competitive and also fun.

[Lozza]

Parts books are NOT proof of eligablity.Why because of 'Homologation Specials' etc RA 125's being a good example factories printed the part number and the option for FACTORY racers and to get around rules. All Doc has to do is to find evidence not a parts book of the swing arm beng raced within the period.

[monaro308]

Could i turn up on one of these in pre78?

http://motorbikearchives.com/Features/Bike-Set-Up/JD-Suzuki-RM125B-Package-Racer-1978.html

[TM BILL]

short answer NO 

[LWC82PE]

agree

[bigk]

So why should Doc or anyone have to provide "proof" when rule 16.4.0.9 is applied?
Cheers,
K

[firko]

Based on 16.4.0.9, all one should have to do is to prove that their post 1978 swingarm is visually indestinguishable from the so called optional version that was available in 1977. That would involve removing/modifying the different bosses between the fixed/floating brake.

Published proof by way of photographic or dated advertising evidence is essential. I've recently gone through this to legitimise the alloy B&S swingarm on my pre '70 Maico. It took a lot of searching but now have advertising and manufacturer proof that the Boyd and Stellings swingarms were available for sale in 1969.

[090]

16.4.0.9 Major components that were manufactured
         outside a specific period, but which are
         visually indistinguishablefrom period
         components shall be eligible for that period.

The '77 had a steel arm and the '78 had an alloy. Isn't this what its all about? That IS visually distinguishable.
If I read 16.4.0.9 as it was written, if a major part looks exactly the same then its okay to use. In this case it isn't and is not after market.
I think it was a good question that Doc asked as there is a swing arm in a parts book which makes one ask the question. What hasn't happened from what has been said so far (unless I have missed it and will stand corrected) is that nobody has said that they had one or saw one back in '77.
Its more logical to assume that the swing arm does not conform to pre '78.
Like Doc says , he won't be running it in a national title and that's when it really counts.
Its a free country but I personally wouldn't run it though as it is indistinguishable from a '78 Suzuki arm which is why there is an issue in the first place.

[motomaniac]

16.4.0.9 Major components that were manufactured
         outside a specific period, but which are
         visually indistinguishable from period
         components shall be eligible for that period

This clause is part of the regs for roadracing - not sure if we should be quoting it in regard to motocross racing

[GMC]

Firstly,
16.4.0.9 is from the historic road section, I think this is well written & should also be in the classic MX section along with ….
16.4.0.7
16.4.0.8
16.4.0.10
16.4.0.12

Secondly,
The proof needed is to show that it was available & used.
16.4.0.9 basicaly says that if the 78 part is the same as 77 part then it is acceptable.
And it’s not, the 77 part was steel & a different shape.
But it appears that the 78 part is the same as the 77 optional part, so the only proof needed is that the optional part existed.

This goes for all parts including the PDI & Brads swingarm in other threads.
They look period to me but I don’t know when they were actually produced.

This might all sound very anal, (it does to me when I type it) but the other option is open slather on all parts which I believe would lead to the “spirit of the era” being lost forever.

As for the “yes or no” answer, well it’s no surprise to me that any scrutineer won’t definitely say based on internet chat room proof, they would want to see it “in the flesh.
The above add is one reason why, first claimed to be from 77 then outed as 79.

I see many people want to use the fat bar hypocrisy as a reason to run some later part but I find this quite poor reasoning.
“Joe Blogs is running an electronic ignition, even though I can’t see it I should therefore be able to run the later barrel, swingarm, case, fork etc.”

I guess there is a bit of hypocrisy their, but the line drawn in the sand is simple, show that the part was around & you can use it.

[JohnnyO]

I'm backing Doc 100% on this one. I was racing in '77 on an RM125B when the Phil Thew Moto bikes started using the optional Suzuki alloy swingarm on their current B models long before the '78 C had seen light of day. As i said earlier a mate of mine then bought the optional Alloy swingarm for his RM125B through Phil Thew Moto and it came painted black. I also have the Suzuki parts book dated April 1977 that lists the Alloy swingarm as an optional part for the '77 B model.
How much more proof do you need??

[090]

Well I do stand corrected as you had said it previously . So I imagine a magazine photo is what is required? Certainly is worth the effort to prove it that is for sure.