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

[DR]

yeah I know, Doc, have another cup of shut the phuck up! this debating is all very entertaining but there is still no simple yes or no. Sorry Dave I don't hate you or MA or the rule book and I'm not trying to send you bald (like me ), I'm pushing the point because they 'were' available and for someone like me I'd have had more chance buying the optional genuine swingarm from Northside Suzuki or Mayfairs than I'd ever have had buying the big name US stuff which I only ever saw on super bling or big budget race bikes or in magazine.

 I can't recall as a kid seeing accessory swingarms on the shelf at the local bike shop so what's the difference, both would have to have been ordered? Here I'm offering up an item that was around and is still around locally today if you hunt, it offers up a little tarting up without removing the bikes appearance from the era. Although not in any great numbers in the day but then I don't know anyone who ran a Thor or DG or FMF or any other brand as we simply couldn't afford them. Big deal it's an alloy swingarm from '78, it's appearance' for all rules, intents and purposes is just like the original '77 B model optional arm yet still it isn't admisable? Allow or disallow this item and the whole deal comes to an end. Evo or any class is fine by me as I won't be at the pointy end when ever I ride but the rule needs to catagorically state one way or another so we know if we can use it the topic really (and probably me) sucks and I'm sorry peoples but if they are not allowed just say so. It's not about rule changes or anything like that it is not the slightest, it's not about cheating or pushing the boundries, it's about ya or nah and that's all.

[TM BILL]

Doc try this formula with the original and then with the alloy one  see if makes a difference 

http://www.classicmotorsport.org/ecmo/calculatie/motocycle_calc_uk.htm

[Davey Crocket]

Doc, why dont you talk to Dave about it, get all the information required, submit it to MA or whoever and see if you can get the swingarm allowed. I dont think it will pass the way you mounted the brake stay ( would have to have the tabs welded on the swingarm as per "B" arm ) and definitly no floating brake. That way it's all cleared up for ever!. You still carn't run C forks though mate as all of the part numbers are different and they have more travel!!!, anyway thats my thoughts on it, I hope this helps, cheers John.

[Davey Crocket]

Geez Bill, now he's gonna go into "overload", .....Warning.... warning.... danger Will Robinson......

[GMC]

I thought Dave answered it back on page 2, it's just been a soap opera since then.

If you arrive at scruitineering with a C swing arm, regardless of where the brake arm is attached I will be sending you away. If you arrive at Scruitineering with proof that your alloy arm is the unit that was available as an option in 77 then I will be happy with that.

I would consider proof as...
Magazine articles showing the arm being used, (doubt you could use Trail & Track photo's as it was hard enough to tell what brand you were looking at let alone the swingarm )

Receipt for one sold (I imagine next to impossible to find although I have all my receipts for bikes I bought.)

Sales Brochures.

Parts book, although for some reason the rule book says this isn't enough?  The parts book dated late in the year I would be a bit suss about because it may be an upgrade part for the following year but if you have a parts book dated early in the year then it would add more weight to it.

Please keep in mind though I am not a scrutineer.

I think Doc asked a fair question & it's good to get these things out in the open. It's not about changing any rule but establishing if a part was available

[DJRacing]

 I can't recall as a kid seeing accessory swingarms on the shelf at the local bike shop so what's the difference, both would have to have been ordered? Here I'm offering up an item that was around and is still around locally today if you hunt, it offers up a little tarting up without removing the bikes appearance from the era. Although not in any great numbers in the day but then I don't know anyone who ran a Thor or DG or FMF or any other brand as we simply couldn't afford them. Big deal it's an alloy swingarm from '78, it's appearance' for all rules, intents and purposes is just like the original '77 B model optional arm yet still it isn't admisable?

 It's not about rule changes or anything like that it is not the slightest, it's not about cheating or pushing the boundries, it's about ya or nah and that's all.

Doc,  unwittingly maybe you have answered your own question ??

[LWC82PE]

I have found this really simple to understand

If the OEM part is listed in the 1977 model parts book/microfiche as a standard part or optional part - then YES it is allowed pre 78
If the OEM part is listed in the 1978 model parts book/microfiche as a standard part or optional part and is not also listed in the 77 model parts book -  then NO its not allowed for pre 78

Aftermarket 'major' components are a little different

eg a swingarm.

If you have one that you can provide evidence/proove that the one you have was available for purchase or made up to dec 31st 1977 - then yes it is allowed pre 78

If you have one that was bought or made after 31st of dec 1977 and you can proove that it is exacltly the same as the one that could have been bought during 77 - then yes it is allowed.

For example only. If DG made 2 swing arms for a 77 RM 125 during 1977 and these went to a dealer. You bought one of these on the last day of december 1977 and still have it now, then yes it is allowed pre 78. If your friend saw yours, thought it was great and went to the shop as soon as they opened in January 78 and bought the other swingarm and still has it now then that is also allowed. These DG swingarms for the 77 RM125 were so popular that they had to start making some more during 1978. Any one who bought one of these made during 78 or later would also still be able to use one of these in pre 78 as long as they can provide proof that it is the same as the DG swing arms sold or made during 77 for the 77 RM125.

And lastly if you have a aftermarket replica/reproduction of a swingarm, then you need to show proof and it has to be/look pretty much exactly the same. This could be hard to proove especially if you do not have evidence showing dimensions of the swingarm you have replicated. Would be a tough one to police/proove i think.

[motomaniac]

I have found this really simple to understand

If the OEM part is listed in the 1977 model parts book/microfiche as a standard part or optional part - then YES it is allowed pre 78
If the OEM part is listed in the 1978 model parts book/microfiche as a standard part or optional part and is not also listed in the 77 model parts book -  then NO its not allowed for pre 78

Aftermarket 'major' components are a little different

eg a swingarm.

If you have one that you can provide evidence/proove that the one you have was available for purchase or made up to dec 31st 1977 - then yes it is allowed pre 78

If you have one that was bought or made after 31st of dec 1977 and you can proove that it is exacltly the same as the one that could have been bought during 77 - then yes it is allowed.

Good post Leith but whats the difference between a period aftermarket or reproduced replica made arm to the proven same specs as a 77  items and a 78 arm thats been put back to these same  specs.Specification wise none .In theory one could get a GMC arm made up from scratch to original specs and if you were capable you could even make your own replica and that would be okay but you cant take a 78 arm and make your own modifications to achieve the same specs???Come on.
In the meantime another guy is building up a bike with tapered bars, PDvales and ext adj shocks that not even the works bikes of Rahier,Watanabe and LaPorte had in 77 but its not an issue?? Come on.

BTW with the issue here being a brake stay mount tab I scanned this from an MXA 1977

[LWC82PE]

I dont know, i dont make the rules or necessarily agree with all of them.

[DR]

yeah good points Leith but this is getting really really over tech and the simplicity that should be in place just doesn't have the clear cut answer.

Bill, I'll answer you first as yours' is easist..the optional swingarm is of exactly the same measurements as the C swingarm but this is not so for the aftermarket arms. So which arm is closer to the actual period items in both looks and dimensions??

http://www.skypoint.com/members/pfuhlman/swingarm-measurements.txt

As for optional parts, e.g. I can run all the 'pre'75 TS or TM kit or aftermarket parts I can get my grubby hands on including aftermarket alloy swingarms to replace the conventional steel item. I can use all the bling parts under the sun but ask if 1 can use the genuine 1977 optional or 'kit' arm on an RM125B and all hell breaks loose.

I'm sorry for the bullshit going down here, it's not about winning or trophie hunting, it's not here to stir shit. It's here because there seems to be some unknown ruling that dis-allows this period correct item.

I can near bet the majority of the aftermarket swingarms now in use in VMX downunder were most likely imported from the US 'after' the fact. Where lies the difference??

this is allowed


but this isn't..I'm sorry but I don't see any reasoning why



Davey the C forks may have a different part number but if I swap the caps and remove the internal spacers then I challenge you to spot the difference without micrometers the travel can easily be bought back into legality if infact is is any different to the B, from all my experience they offer exactly the same travel, performance and exactly the same appearance. This is where I'm finding it hard to understand..you can internally mod all the forks you like with late model internals so long as they appear externally the same yet I can't use the C forks when infact all they are are B forks with aircaps and 'maybe just maybe' some slight change to the damper rod or shim stack. 

I will take this up with Dave and MA because to me it seems an inconsistancy. Be nice to know what others thought first though for fear I'm missing the obvious hence the post.

[TM BILL]

Chris my personal take on it is that pre 78 is a unique class . It caters for that 1st generation of LTR bikes and in my biased opinion the Suzuki RMB range were and are the best bikes for the class. The suzuki RMB range did not leave the factory with Aluminium swinging arms they had steel ones .
One of the most visually distinctive features of the following years RMC models was and is the aluminium swinging arm .

Did any other production bike in 1977 have an aluminium swinging arm as standard equipment ?

The aftermarket swinging arms that were and are available for the RM B models do have a different look and an identity of there own . Herein lies the difference , bolt in a RM C or RM B optional SW arm and it looks like the following year models part, where as an aftermarket SW arm looks just that aftermarket , trick , special or in the case of the one in the other thread ugly .

Using C forks without the extenders , who would pick up on that ? not me .

Floating rear brake on your RM B as long as its of your own design and DOES NOT USE PARTS FROM LATER MODEL BIKES go for it.

I struggled with the no riding up into pre 78 rule on a TM 125 , if i modified the frame so the shocks can be laid down for pre 78 and put back up straight for pre 75 at the same meeting why cant i ride both classes on the same bike.
But when in a previous thread it was pointed out that pre 78 is a class for those 1st gen LTRS only FAIR ENOUGH

I know you want an official answer and of course i cant give you that  just an opinion . The evidence seems to stack up that those arms were available in 77 as an option . However for me they dont look right in pre 78 

Either way i have 4 of those arms 4 sale , 2 with tabs 2 without  pm me if interested .

[DR]

ok Bill here's my take. If the arms are painted black will it still not look right? The reason the C swingarms may look a little out of place is only in our generations eyes i.e. we never saw many of the optional swingarms fitted because ppl all wanted the bling psych out aftermarket jobs and very few even knew of the genuine optional arms existance. If we did see the optional arm we probably didn't realize as they were painted black. Fact is, they did exist and in the correct era and that's what the rule book requires. The reason they may not look right to some people is the simple fact they are polished not black and the polished look obviously makes it stand out and grab a little more attention as do the alloy aftermarket jobs. Suzuki during the '75-'77 era were leading the way so this alloy option doesn't surprise me given everyone else was still using steel. It was an option, it exists and it's within the era. Someone mentioned their parts book also lists the arm and the book was printed early in 1977 so it's not a '78 only thing by any stretch of the imagination. Whether we all knew of it or not the fact is in black and white it exists and it was an option for the B. I dunno, I can't say anymore as the facts speak for themselves, how can you discount something that exists? I really don't mind either way but and would like to draw a close to this topic but I can foresee problems arising if someone contests eligability as it stands because it does conform to all the rules regardless. Whether it sits right in our eyes/ideals seems to be the deciding factor    

[TM BILL]

You know its funny you say that , iv'e got a 250 /370 optional arm with tag that i got out of the states some time ago and thats painted black . I thought somone had done it after the fact but maybe thats how it came new

[VMX247]

Is Dave T the only Eligibility person for Classic MX ??
cheers

[211kawasaki]

No