RM125 B SWINGARM

[GMC]

There is absolutley no difference between a 74 75 76 KX 125 frame yet 75 and 76 are not flow ons go figure

Are you sure it's not considered a flow on?

Part # = 32002-091
Part Description = FRAME
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

Part # = 33001-072
Part Description = SWING ARM
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

Part # = 44001-142
Part Description = FRONT FORK
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS


Part # = 11001-101-21
Part Description = CYLINDER HEAD,FLAT BLACK
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

Part # = 11005-135-21
Part Description = CYLINDER,FLAT BLACK
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

Part # = 13036-047
Part Description = CRANKSHAFT ASSEMBLY
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

Part # = 14001-5149
Part Description = CRANKCASE SET,FLAT BLACK
Model Count = 14
KD125 75 125 KD125 MOTOCROSS
KD125-A2 76 125 KD125 MOTOCROSS
KD125-A3 77 125 KD125 MOTOCROSS
KD125-A4 78 125 KD125 MOTOCROSS
KD125-A5 79 125 KD125 MOTOCROSS
KE125-A3 76 125 KE125 DUAL PURPOSE
KE125-A4 77 125 KE125 DUAL PURPOSE
KE125-A5 78 125 KE125 DUAL PURPOSE
KE125-A6 79 125 KE125 DUAL PURPOSE
KS125 74 120 KS125 DUAL PURPOSE
KS125A 75 120 KS125 DUAL PURPOSE
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

Part # = 41034-031-21
Part Description = FRONT BRAKE DRUM ASSEMBLY,FLAT BLACK
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

Part # = 42008-019-21
Part Description = REAR HUB COUPLING ASSEMBLY,FLAT BLACK
Model Count = 3
KX125A 75 125 KX125 MOTOCROSS
KX125-A3 76 125 KX125 MOTOCROSS
KX125 74 125 KX125 MOTOCROSS

[Simo63]

The same applies to replica frames, engine cases and brake backing plates they are completely legal yet are made using modern material and processes. I don't think anyone suggests they should not be legal. If a part is identical in every way to an earlier bike then it would be legal. An RM125C engine is identical in everyway to an RM125B so can you run the 'later' engine. I would say yes because for all purposes it is a 1977 design

We're talking swing arms here, not frames, brake backing plates and engines  

Mental note to one self .. keep out of discussions involving eligibility of parts  

[John Orchard]

A C model cylinder and head have increased finning over the B model .Its easily identifiable.

C and B finning are the same, it was the oversquare A model with less finning.

[Ted]

Ok, so a 78 C model turns up with a B arm on it, how do you tell the difference

Are forks bigger, rubber mounted bars, engine numbers different, frame number different, turbo fitted. What distinguishes the C from the B

[John Orchard]

I smile every time this RM125B alloy swingarm subject comes up, but I still enjoy the read  LOL   :-)  I'll break it down in to point form as I see it ....

* The part was listed in the 1977 parts catalogues.
* Other brands of alloy swingarms are legal for 'pre 78' (and the Suz one is not as good as those!).
* The fact that they came fitted to the first batch of C models released in late 1977 proves they were actually made.
* The part in question is different to the actual item on the very next production C model.
* There are many enthusuiasts that would like to run them, it's not like they're fitting anything that would give any significant advantage.
* Some VMX riders have mentioned seeing the actual item in 1977.
* The more this matter is dicussed, the more it appears it should be allowed as many think it is a unique part.
* Even many riders that don't ride the 'pre 78' 125 class are cool for it to be allowed.
* Part of racing VMX is about customizing a classic bike, if many want to do it, let's make this a happy world and allow them.
*  The fact that this is a small community in which we all want to have fun and admire our bikes, this matter should officially be put to bed immediately.

Now .... I read somewhere that there was a Unitrak conversion for my KX250A5 back in 1979, you're all cool if I run it yeh?  ;-)

[motomaniac]

A C model cylinder and head have increased finning over the B model .Its easily identifiable.

C and B finning are the same, it was the oversquare A model with less finning.

You sure ? If so thats another nazi myth debunked.

[motomaniac]

http://www.ebay.com/itm/1978-Suzuki-RM125-Aluminum-Swingarm-AHRMA-Vintage-MX-/221201614068?hash=item3380a4c4f4&item=221201614068&pt=Motorcycles_Parts_Accessories&vxp=mtr

Ended up  bargain .Why not buy this instead of a 21 century "replica" for hundreds more.

[John Orchard]

A C model cylinder and head have increased finning over the B model .Its easily identifiable.

C and B finning are the same, it was the oversquare A model with less finning.

You sure ? If so thats another nazi myth debunked.

Yeh I had a B & C barrel for the RM I just sold. The only difference was the C barrel had more distance between the tranfers & exhaust port, so less fuel was lost out the exhaust, more midrange was the claim.

[motomaniac]

[/quote]

You sure ? If so thats another nazi myth debunked.

[/quote]

Yeh I had a B & C barrel for the RM I just sold. The only difference was the C barrel had more distance between the tranfers & exhaust port, so less fuel was lost out the exhaust, more midrange was the claim.
[/quote]
yer I knew about the transfers,I got the ADB artile for porting. I was going on information stated by the "experts" from the previous 27 pager. Cheers JO

[motomaniac]

So to stop people using the genuine optional arm just in case someone modifys a C arm is ludicrous .   

said me NEVER.

I'm not even sure Don was serious with this post but it highlights the potential problem.

But like Brad, I don't care what people do.  I don't even have a bike in this class, I was just commenting on what I saw as a potential issue if/when the alloy arms are accepted in pre 78.  All of a sudden there might be 100 of them when only 20 really existed (to use Brad's numbers  )

So what? Why is that not in the spirit of the sport when instead of just fabricating a lug to go on a existing genuine part
whole arms are "replicated" from stock that ARE NOT EITHER  original oem or aftermarket from the era and noone says bo.

[mainline]

So basically you just need a genuine 'optional' arm from 77 or an early C arm with the bushes instead of bearings and sort out a brake lug.  Simple

What's next?

[JohnnyO]

Ok, so a 78 C model turns up with a B arm on it, how do you tell the difference

Are forks bigger, rubber mounted bars, engine numbers different, frame number different, turbo fitted. What distinguishes the C from the B

The C model has a plastic tank which bolts to the frame unlike the B, and different front and rear guards, the C forks have alloy extenders attatched to the top of the legs and the forks stick up through the top clamp about 50mm resulting in the handlebar clamps being angled back and rubber mounted.
It has the alloy swingarm obviously and a floating rear brake and a different rear hub more like the 250/370.
The porting is a little different and the rest is pretty much the same as the B.

[Ted]

Ok for a C model to have an advantage over a B model it would have to have these things on it which wouldn't be very hard to identify. No contest

[TM BILL]

Yep last time i checked  however i dont have a current moms  to me its always been a huge oversight but because theres only a few around it seems no ones bothered .

The 250 , 400 , 450 are all completly different but the 125 should be listed as a flow on 

[crs-and-rms]

my c swing arm that came off the first 30  frame numbers has the lug and needle bearing.the other c swing arm i have came with bearings or bushes removed but they look the same size .i cant see any differance