OzVMX Forum
Clubroom => Tech Talk => Topic started by: asasin on August 25, 2008, 10:33:11 am
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Hi can anyone tell me what swingarms (alloy) are allowed to be run on a pre 78 Rm 125 B for nationals also are gripper seat covers allowed?
Thanks
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Gripper seat=OK. The swingarm is regarded as a major component so therefore it must have been manufactured, or be an exact replica of an item manufactured prior to December 31 1977. Those FMF, Thor and DG RM A/B replica swingarms look OK but Novation arms are illegal by my interptation of our rules as they don't replicate anything from prior to 1978. I don't think the RM C swingarm would be legal as they came out in '78. In reality, it wouldn't matter three fifths of FA but rules is rules and the class is pre '78.
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Thanks , I also forgot to ask ,full floating rear brakes??
Cheers
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get a hold of a genuine parts book suzuki had a optional extra alloy swingarm guessing it would be the same as a c. i had 250b and had the parts book so i would reckon the 125 would be the same
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that wouldn't be the 250 c2/400 swingarm would it?
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its in my parts book to ,it was printed in april 1977 and is listed for the rm 250 c not the b and its the same as the c2 swingarm
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Very interesting.That should make it pre 78 legal-----shouldn't it? You learn something every day!
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Shoreline is right, i have the '77 RM250 parts book and the alloy arm was an optional extra. I remember in '77 a mate of mine bought the optional alloy swingarm for his RM125b and it was the same as the one that came standard on the C except it was painted black. So yes it should be pre '78 legal.
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to save any woes I'd stick to the steel box section arm..the steel looks more like the RA125 shape ;D (though it would have been some priceless lighter than gravity metal..maybe even alloy!) but full floating rear brakes had been around long before pre'78 so if you can find/make the parts to do the swap then go right ahead. My '73 F11 has the floating rear setup stock ;)
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Just looked at my brochure and sure enough the A model 250/370 came standard with a floating rear brake.
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Interesting replys guys thanks . I had a 77 b with a genuine painted black alloy (same as C) swing arm that my oldman got for me early in 78 (which i go faster paint stripped to look cool)It must have been one of the ones mentioned above as it came off a 125 A road racer,I was only 15 and dont remember the full detail and my dad has passed away so a problem asking him!. I have a 78 arm here so should I paint it Black to be legal?I just dont want to get to a event and have it chucked up a class
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Asasin, the alloy swingarm , the plastic tank and the cush mounted bars, floating rear brake are basically the only noticable difference between the B and C model. I don't agree the C belongs in evo either as it is far more closely related to the early pre'78 models and not the later '79/'80 models thus it should slot in with the pre '78s. Since this is my opinion and since rules are rules I set about coverting my C back to pre'78. I used an 125A frame, 125A tank and 125A steel swingarm and the rest is basically C but it's now perfectly legal. Go figure ;) If it wasn't for the tank and swingarm a lot of people would be hard pressed to tell the difference between the '77 and '78 such is the closness of their build but if someone wants to cause shit then the alloy swingarm is a debateable point regardless of availability pre '78.It didn't come out stock on the production bike and I'm guessing for this reason it is not legal. I'd love to be wrong so I could bolt my alloy arm back on after I spent a small fortune fitting new bearings, bushes and sleeves then promptly placing it on the shelf where it still sits ::)
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Good Point Doc , i think Ill take to the steel one with a Drill and leave the arguments to someone else. cheers
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Hi again , Would someone with a RM C please have a look at their swing arm for me and tell me if the brake control arm has a unused Pickup point on the swing arm( same place as a not floating brake would go), i have found one that has and i hope it is a optional B model one.
Many thanks
John
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Incidentally, the exact situation came up her ein the US in AHRMA. A young racer had 77 RM125B with the alloy arm. While he provided documentation that the alloy arm was an accessory in 77( with the same catalog spoke of here), he was unable to document that exact arm on his bike was, in fact purchased before 78.
IMO, splitting hairs. I suppose I am glad to not have been the tech inspector ( scrutineer) on duty when it occurred-as I disagree with the decision. Still, I understand that it would open up the gates to anyone else running later factory alloy arm in Historic( pre-78), but find it a moot point..why? I agree the 78 RM125and 250 at least( if not also the 78 RM400) could be pre-78 legal.
It seems to me that both the 75 models and 78 models( excepting the 78 CR250, and Maico magnum) are left to dry. While the RM125 and RM250 are top performers already in pre-78, I think it unlikely that a 78 bike would be a notably better performer. Also, we already allow the 78KX125A4, and 78 KX250A4 in pre-78.
I agree they belong in pre-78 by design and performance, but would say the 78 RMs do as well. To me, the determining factor would be over 10" travel stock and a moved back countershaft sprocket( like the Maico Magnum and 78-79 CR250) which make a difference with 9" of travel. The pre-78 bike have a tensioner setup( which robs power, even if it is a just a bit-but also more likely to have erratic chain movement etc, subsquent gearbox wear etc). Just my take on it.
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Yup well I have the book and it is definately listed as an optional extra on the RM125B so therefore there is no contest. It is acceptable. Just because you can't prove the arm was made before 1978 you cannot also not disprove it so the contention will rage. In all reality near all the swingarms for the C model were manufactured in 1977 as obviously the parts supply had to be in place before production of the C ever began. The 400C isn't really pre'78 eligible as the bike changed too much from the previous year. Engine dispacement and plastic tank the deciding factors along with the swingarm which I am not sure was offered as an option for the 370B. The 250C should be eligible as it is a direct flow-on. Excepting the C2 which had the alloy arm and plastic tank they remained virtually unchanged from '77. I'd reckon if the plastic tank was swapped for the alloy A or B 125 tank then this should make the 125C eligible. I can't prove manufacture dates on 'any' of the parts on any of my bikes except the inner crankcases and frames and there is no visable benifit in running a C so how can this argument have any foundation? Something else to think of is allowing the C to run pre'78 makes this model far more desirable as a racebike and saves the C from the miss match of being thrown in with the 125N's or T's in Evo's. I believe the YZ125E, 250E and 400E should also be eligible but that's another can of worms. So far as I can see allowing these models to run pre'78 would be benificial on the whole.
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point taken Doc .. I see where US AHRMA are comming from also . Whats to stop a rider buying a C ( 1978 arm ) and putting it on his bike and saying it was an option in 1977 . The point I'm making is he sourced the part off a 1978 model ;)
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Does it realy make that much difference if it's a steel or aluminium (not alloy) swing arm? I don't think most rider would notice any difference between the two. The amount of unsprung weight between the two wouldn't help 99% of riders from our vintage and capability in achieving a chequered flag anyway.
I make a point of bracketing the term "alloy" in the above sentance for a reason. From my understanding "alloy" describes mixing various elements with a base metal to form metals of different charactistics, for some reason everyone is now calling aluminium, "alloy". We seeing it written everywhere where people obvoiusly know no better, boat builders are good as an example (Allycraft exception), and I see it all the time in this forum as well. If we all want to shorten the word aluminium, why don't we call it "ally" instead of by the incorrect term of "alloy".
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PMC. I used the term "alloy" here as it appeared to be the vernacular. After a while here I am also using the term "bloke", "cheers" , and "shitbox".LOL
My american friends are puzzled with some of these...
About any Aluminum swingarm is an aluminum alloy of some sort, just as about any steel is an alloy of sevarla parent metals too.
I agree with Doc on the 78 Yzs as well. Pre-78 needs more participation-not less.
Since I am not a fan of decade classes, I am a fan of loosening up the eligibility in some classes to help them. Let's take pre-78 500, well the 78 YZ would be no benefit over the 77 in reality-and would not change that the 370 Bultaco, 400-440 Aw Maico, RM370, and Monty VB-as well as the KTMMC5 400 are IMO the btter performers in the class anyway. Allowing what we have spoke of will not give dominance to RMs with alloy arms, nor YZs, it will just let more bikes in the class.
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Soooo ,Who makes the call? ???scrutenineer on the day or can a ruling be got before a national event?
the one have is nearly 1 Kg lighter and this makes a differance to shock settings etc.
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PMC. I used the term "alloy" here as it appeared to be the vernacular. After a while here I am also using the term "bloke", "cheers" , and "shitbox".LOL
My american friends are puzzled with some of these...
About any Aluminum swingarm is an aluminum alloy of some sort, just as about any steel is an alloy of sevarla parent metals too.
I agree with Doc on the 78 Yzs as well. Pre-78 needs more participation-not less.
Since I am not a fan of decade classes, I am a fan of loosening up the eligibility in some classes to help them. Let's take pre-78 500, well the 78 YZ would be no benefit over the 77 in reality-and would not change that the 370 Bultaco, 400-440 Aw Maico, RM370, and Monty VB-as well as the KTMMC5 400 are IMO the btter performers in the class anyway. Allowing what we have spoke of will not give dominance to RMs with alloy arms, nor YZs, it will just let more bikes in the class.
Good points MaicoJames and Doc. I like the thinking and that it would add more bikes to the class (I have a YZ125E) but at the same token I feel for the older bikes of the class (YZ125C-RM125M/S) which once again become the old dogs of the fogotten era. There is always going to be the worse bike of an era and for that fact it would be a shame to have the development bikes of long travel suspension be relegated a long way to the back of the pack through a rule change basically making the '75/'76 bike obsolete over night. It is hard enough for the older bikes of this era to compete in and the '77 bikes did a big leap ahead and therefore instead of raising the year to accomodate some '78 model bikes and have a class full of just '77/'78 bikes I believe the the YZ125D and RM125B should be disallowed in pre78 racing and should move up to pre81/Evo/ (or what ever the class is named) as I think they will still be on the pace and not look out of place in that era. Concerning the then lack of numbers in losing two models' of bikes I feel wouldnt be an issue as once the two 'hot ticket' bikes are gone then maybe more of the older bikes of the class would be raced and not out suspsended and out paced. (just my take on the subject)
If the part is in the suzuki parts manual for the '77 RM125B then it is without doubt a useable part for pre78 racing.
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Good points DJ , but a rms is hardly an old dog , they go very well and are compeditive with early a, and b and even c model RM.Their motor is easiily the match power wise ( even if they are harder to keep on the boil) The only time a N or T model has the advantage is on a rutted out track or if big jumps are involved that is when a B/C Model will suffer .I used to race all these models and know the advantages and disadvantages of each model .I dont know about the YZ I have had no experance with them. No matter what year cut off there is the lastest in that era will be the "hot ticket", thats why the fastest pre 86 bikes run the latest forks/brakes etc from that era.even if they are 82/83 bikes . it will always happen no mater what type of Motorsport is involved. I will quite happily run a steel swing arm and set up the bike accordingly . But if it is allowed to run a lighter one I would as with a 125 every KG counts.
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DJ, I get your point, but respctfully disagree. There had been some talk of Vintage Grand Prix classes for the 75 model bikes( including the 76 bikes which are alike-such as Monty VA, YZ-C, 76 CR 250 and a few other which escape me now).
Putting the 77 model bikes in with the later bikes has been done in the NW US-and almost no 77 model bikes race. When we go back to the moved back countershaft-as seen on the 78 and up Maicos, the 78 and up CR250s etc-I think this is the correct deliniation and cutoff. Even the top performers in the pre-78 would be at a perfomance disadvantage against bikes engineered as longer travel bikes.
I realize the RMs had the counter moved back more than a Maioc of the era, but it is not the same. That direction would kill off more pre-78 entries IMO.
Again, the 77-78 YZs are basically sister years, while the 76-78 RMs( I will spot the 78.5 RM400)are as well. We need more of these bikes at races here( and I think abroad from what I understand), and strongly believe that offering the more plentiful and currently undervalued 78YZs and RMs to pre-78( Historic here in AHRMA) would allow more to participate. I disagree that a 77 YZ or RM looks the same era as an 81 Maico either. 78 was a transition year for some( like 75 was for all), and at least the YZs and RMs belong in the pre-78 era ( with their ten inch or less travel etc). As for the aluminum arms, this would kill that debate also.
Personally, I have no problem with a 78 YZ or RM250 lining up against me on a 77 bike ( like a 77 KTM, or 77 Bultaco, or 77-78 Monty VB, or 76-77 Maico AW), or the same in the 500 class. JMO, and probably wrong. LOL
James
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It is a contentious issue but if the part was available during that era then it is acceptable now, even copies of aftermarket swingarms are legal so long as it is a direct copy of an era item. As for the pre'78 I believe the dwindling numbers in this class could be improved by adding '78 models. Very few people would pick a '78 model over a '79 or '80 model knowing full well the suspension of the later model worked so much better over tracks that at the time were also undergoing a radical change from the regular Euro type outdoor circuits to the indoor or stadium type tracks. The pre'78 models were built to run on the older style tracks and this is where I believe the main difference lay. The '78 is the last of the 'oldschool' RM's, in '79 the whole MX scene changed and so did the bikes. Maybe there are some '78 models that have super trick suspension and or some other design that puts them ahead of the field but how many of these models do you see in comparison the the normal everyday Jap MX'er that most people run and how often do you see the nicest bikes winning? I'll shut up now as I'm repeating myself and others comments but 'pre78 is a fav era of mine, from what I can see there has definately been a miss match by throwing a '78 model in with the Evo's.
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Let the 78s in :) makes my KX 250 A4 a contender :) just needs a good pilot ;)
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a good rider as opposed to a broken rider Bill? ;D sorry bloke couldn't help taking a stab ;)..how's the leg coming along? and yeah, let the A4 Kawa's in for sure!!..if it's '78 it's in for my way of thinking but that means zac obviously except in my own mind :-X
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there are some '78 models that have super trick suspension and or some other design that puts them ahead of the field but how many of these models do you see in comparison the the normal everyday Jap MX'er that most people run and how often do you see the nicest bikes winning
I understand the logic towards moving the goal posts from 1978 to 1979 but will throw a devils advocate situation at you. In 1978 Maico introduced the new Magnum model which featured the new generation small case engine and one of the most advanced frame and suspension geometries of the period. What's to stop some dodgy punter fitting a 490 top end to a '78 440 and blitzing the field? By keeping the cut off at pre '78 you are keeping out the newer greneration Maicos, Huskys and Hondas that are more in line with the Evo period. For every '78 model Suzuki, Kawasaki and Yamaha that "deserves" to be in because they follow first generation long travel suspension philosophy, you have bikes like the Maico, Husky and Honda who took their engineering to the next level in 1978. I believe the '78 cut off is the fairest for the reason that it keeps those bikes out. Unfortunately there is always going to be bikes that miss out by a year but we can't keep proposing changes to keep the owners of one particular bike happy. Some miss out, but isn't life like that?
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Firko first the dodgey punter has to be able to ride well enough to win. If the bike is absolutely decimating the field then no doubt at a titles or such someone will raise a protest. As you yourself have said before, get caught cheating at VMX and you instantly go from being accepted to being labeled a cheat and loser in 2 seconds flat. What's to stop anyone doing anything they like internally to any model they so desire? I could fit a 6 speed into the TM125 and bore it out to about 140cc and race it and no one would know. Same thing really.
How many of these super desirable '78 model bikes are out there and how many would have the gun riders aboard who could clean up?? Probably not many.. I'm not about changing rules to suit my bikes or any personal reason. I doubt I'll ever race my '78 400 again so it's not like I have a huge passion to do so. The '78 125C is certainly eligable for pre'78 if you simply swap the fuel tank. The rest is the same and it takes a good eye to pick the differences. The '78 CR250's were trick yes but how many do you see as compared to YZ's or RM's. If there are trick pre'78's out there isn't enticing them out of the wood work beneficial to all. We're old buggers and I really couldn't care less if the guy beside me runs a modern because at the end of the day it is a form enjoyment and not to be taken seriously. There's the few who do take everything all so seriously ::) no sheep stations to be had vintage racing and we all have to turn up at work monday. It's a lot of trouble to change rules and cutoff's I know but with a few contentious issues in regards to eligablily arising I think this era in particular needs looking at. The 125c model alloy swingarm definately being available for the'77 B opens a can of worms. If not for the plastic tank then the '78 C is a direct flow-on and certainly very eligable for pre'78. If this is the case then so to are the '78 YZ model Yams. To not allow the alloy swingarm for use on the RM125B is changing factual history. It carries the potential to make all aftermarket swingarms a contentious issue in all era's :-\
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;D ;D ;D ;D ;D ;D
Let's get it straight..I suggested ONLY the 78 YZs and RMs in Historic( pre-78)-, in fact I went to lengths to talk about the Maico and CR250 Honda. In AHRMA the 78 KX 125 and 250 are already in. Firko, I accept your points on the other 78s.
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okay..me too, I agree ;D..hey, I'm just offering my thoughts but I too agree the RM and YZ should be in. Just seems a little crook to forbid the majority for the sake of a minority ;)
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The classes are meant to group together models that are similar, not neccessarily models that are absolutely equal.
Allowing some 78's in because they are technically similar may disenchant some 75 or 76 owners.
I find this debate amusing because Nick Smith took his 77 CR 125 to an Aussie title win in Tassie in the 125 Evo class, ignoring the fact that his bike wouldn't be competitive with the later models. Then I read here that someone wanted to ban the older bikes from Evo as they weren't giving the newer models a decent go. ???
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Geoff, clearly I did not spend enough space clarifying that riders can win against newer bikes...Kevin Windham had a go on a 77 Maico and went better than the others on their moderns. I rode a practice day a few years back at a local modern track-a very SX type at that-and went well on my old 77 Maico( not due to my skill, which is zero-but familiarity with the bike)....in early 90s Joe Busby here in Tx won a vet race on his 72 400SB.
On the right track, the right rider will prevail, we should all be aware of the 90% rider 10% bike saying. That said, I am confident my old 77 Maico -on a rough track would hammer through the rough line that has a 75 Bultaco, Monty VA, or 76 CR 250 for example kicking the rider off. So, I agree that almost all 75 bikes-and many 76 bikes would have riders disenchanted-they already should be. They already don't have a class.
A NW US group had proposed a "Trans-Am" class for these 75 ( and select 76) bikes. Most of the 75 bikes are at a techincal disadvantage to the top 77 bikes now.
What I am saying is that the 78 KX 125, and 250-78 YZ125, 250, and 400, 78 RM 125, and 250( if not also the 78 RM400) are so technically similar to their 77 counterparts they present no technical adavantage. While it is the rider, I -if riding say a 76-77 KTM, 76-77 RM, 76-77 YZ, 76-77 Bultaco, 77-78 Monty VB, or 76-77 Maico AW am not intimidated by a 78 KX, RM or YZ on the line...and right now these 78 YZs in particular are comparatively cheap-meaning a few more blokes even with less $ could participate and grow this class. Here in the US, it needs more participation.
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okay, sorry to cut you short guys but getting back to the subject at hand which is the eligibility of the alloy arms for pre'78.
John, had a little hunt around of late and Dodgee agree's (in theory at least :P) 'Supposedly' the way to decipher between the B model optional swingarm and the C swingarm is brake stay mount is welded on the underside. The B didn't have the floating brake setup hence the brake stay mounts under the swingarm same as the steel jobs. Mine has no mounts so it's the C item I guess but I know for a fact my RM400C came standard with these mounts on the underside and so did a new replacement arm I purchased back in the day and another 250C arm I found a couple of years back. I never did understand why till just now when it dawned on me 30 years after the fact! :o All this to me says the 250B/370B had the alloy option in 1977 also. In theory it should make the aluminium 250/400C arms legal for pre'78 as well. I can take a photo of this brake stay mount which 'theoretically' (gotta love that word!) proves these arms were made to suit '77 models ;) contentious to the hilt but I reckon it'd be pretty crook if these arms are not allowed with the information and documentation now at hand proving their existance in and for the specified era.
eeerrr, another 2 pittance worth, I'd also be of the reckoning if the arms are legal then the C is definate flow on model and could rightfully run with the pre'78 as could the YZ's ;) sorry, back to you GMC and Maicojames :)
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I think James & I are agreeing. Everyone usually recognises that the rider is the most important part of the combo but suffers psychological defeat if they think other bikes appear better. I think if being on the cutting edge of technolgy for your class means that much then racing VMX may not be for you.
Interesting deductions Doc, if you want this changed you should document all your info including part No's etc & submit something to M.A.
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Thanks Doc , that pretty much confirms what I thought , the arm tag is only on the "B " model bikes optional swing arm ( which is what I have ) . Now all I have to do is get somone to put it in writing.I have had no response yet but will keep trying. I have another arm(Steel) that has had the mounts move d back to alllow longer shocks to work properly on it so if I am stiffled with this alloy one I will take to that one with the Drill!!!
Cheers
John
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Geoff, John has actually put the question to MA in regards to this swingarm eligabilty. I'm just doing a little ground work as I agree 100% it should be legal. I had a C model and I went and chased up an A frame and swingarm and fitted my C engine and all the other bits into that and instantly I go pre'78 legal so what's the difference if I used a 125C in it's entirety? It's simply not allowed as the C is classified Evo yet every part of the 125C excepting this contentious swingarm and plastic tank is perfectly legal to use on a pre'78 race bike. Seems a little hypocritical to me. If needed, I'll help push the barrow on this one but I'm opting away from organized events so I really don't have a say in the matter and should butt out ;)
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Hi Doc , I have herd nothing form the contact you gave me , I do not have one of your rule books , can you or someone give me the contact at MA directly so i can start the paper trail
Cheers
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I have just brought 3 rm 125 c models and none have the brake tag on them, doc can you scan and email me the parts book entry re optional extras.Im going to try it for the nats i think the case is strong and it sounds like it is up to the scruteneer on the day cheers john
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no problems john I'll scan it a little later. I cannot possibly see how it can be knocked back so long as the tab is either there to start with or welded there later. It makes no difference if it is a C arm or the genuine optional B arm as either way one is a replica of the other. Toss the floating brake and there is no contest when this item was genuinely available in the era. I would have though Mr D Tanner would have given a green or red on this one :-\
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I have managed to track down (by shear fluke) my old Rm B ,or whats left of it . and it definatly proves beyond doubt that the pre 78 swing arm that must be legal for this class is the one with the tag for the brake arm ,oh and paint it black!