Swing arm elegibility pre 78

[asasin]

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

[firko]

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.

[asasin]

Thanks , I also forgot to ask ,full floating rear brakes??
Cheers

[shorelinemc]

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

[mainline]

that wouldn't be the 250 c2/400 swingarm would it?

[crs-and-rms]

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

[suzuki27]

Very interesting.That should make it pre 78 legal-----shouldn't it?  You learn something every day!

[Maico31]

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.

[Doc]

to save any woes I'd stick to the steel box section arm..the steel looks more like the RA125 shape (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

[Maico31]

Just looked at my brochure and sure enough the A model 250/370 came standard with a floating rear brake.

[asasin]

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

[Doc]

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

[asasin]

Good Point Doc , i think Ill take to the steel one with a Drill and leave the arguments to someone else. cheers

[asasin]

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

[Maicojames]

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.