Further to hijacking a brake pedal thread, I thought we might give this subject it's own outing.
Here's where it began  Brake pedal linkage

Here in the UK and in Europe from 1978 our DT175 models were named DT175MX.
I've always thought the MX was an abbreviation of Mono-Cross, Yamaha's revolutionary mono shock suspension.
Hard to confirm either way, but here's an interesting article.
Evolution of the Monocross Suspension

 

I'm looking at this from a "marketing" perspective as "monocross" is definitely a marketing term.  (Kawasaki used "Uni-trak" for their design if I remember correctly).

That linked Yamaha article uses the "monocross" term very liberally....  but I'd venture to say it was written YEARS after Yamaha applied the name "monocross" to their monoshock rear suspension bikes.  And I don't remember "monocross" being used in the early years. 

I'm going to look for the earliest usages of the "monocross" name by Yamaha....

And as I said in the other thread, if anyone has brochures or articles from the early DT---MX monoshock models...  1977 especially...  it would be interesting to see if they ever used the marketing term "monocross" during the introduction in the countries that used the "MX" suffix.

What I've found is in the overseas 1977-78 Yamaha overseas marketing materials they made several comparisons to the "YZ moto cross" engines, frames, and suspension which makes me think the marketing connection they were trying to make is that these were modified to be "street legal" motocross machines?  Hence the "MX" suffix?

Certainly not sure though.

I only really ever knew the earlier, direct acting suspension as monoshock.

I thought monocross came out with the later rising link setup?

I always took it as Monoshock was the name of the single shock itself and monocross was the name of the combined frame, swingarm and single shock absorber set up?

I know in the early days (1976) when Yamaha 1st came out with the monoshock rear suspension everyone refered to it as just that. Quote: Yamaha has the new monoshock rear suspension. Later somewhere around 1981 Yamaha called it Mono X rear suspension, then after all the manufactures came out with there own single shock rear suspensions Yamaha started calling there rear suspension Monocross I think 1984. They had stickers on the swingarm with this name.
Honda called there's  Pro-link
Kawasaki was Uni-Trak
Suzuki was Full-floater
I guess having a name for the rear suspension was a way to identify each brands unique design back in those days as it was all new technology. 

Not sure why Yamaha would name there single shock enduro's in Europe MX and not the U.S.single shock enduro's?  Even the early XT's enduro's have the old style monoshock rear suspension in the U.S and Europe. I don't thik they call the Europe XT models MX do they? I will look at my XT brochure in the morning and see what they refer to the rear suspension as.  

One thing that was different in countries outside the USA is that in some areas you were still able to purchase new year model "twin shock" models OR "monoshock" models until at least 1979 in some countries...  perhaps into the early 1980's?  1G0 and 1G1 models come to mind...  possibly the 1F9 as well?

Here in the US, once the monoshock version was released, that was the only model you could buy that model year.

That might explain why they added an "MX" overseas?...  to differentiate the monoshock from the twin shock versions that were still being sold new? 

I'm not certain at all the MX refers to Monocross, but it was certainly a term used before the DT175MX hit the UK in 1978 and Yamaha are highlighting it in these examples from '76 and '77.
I can say without doubt it's a lot more capable and comfortable than my twin shocks 
Just a quick search in the tech library and Monocross (spelt Monocros) is in the 1977 DT250D owners manual.
Here's a 1977 brochure with the headline "Yamaha Introduces Monocross Enduros"
https://
And another.
The more I read, the more I realise what a huge deal the introduction of monoshock suspension was.
I didn't know the DT was the first mass-market motorcycle equipped with a single-combined cantilever rear suspension.
https://
Found a YZ125C brochure with reference to it also.
davesbikebrochures.weebly.com/uploads/4/...z1251976brochure.pdf



 

Yes, I found Yamaha used the term monocross in the USA in 1974

Are those ads from the Europe/UK market where the "MX" designation was used?  At the risk of repeating myself, the Yamaha importer in the "MX" region seemed to focus their marketing on the "motocross" similarities of the monoshock models. 

I have not found one early Europe/UK advertising piece that mentions "monocross"...  nor any Yamaha literature that equates "MX" to "monocross".  The way marketing works... I just find it less likely Yamaha UK/Europe would mean "monocross" when they added the MX suffix and then not use the term monocross repeatedly in their early ads?

They do however, repeat the term "moto cross" repeatedly from what I've seen.

Hey Mark, I'm leaning more to my earlier belief that the MX in this instance does mean Monocross, we are both entitled to our opinion 
Yes, the ads I posted are for UK/EU market and when I look at them they really push the introduction of the Monocross suspension, but also the motocross pedigree the bikes are derived from.
I have found reference here (not directly from Yamaha) with a quote stating "Over its lifetime, the motorcycle received numerous upgrades and modifications, including a single shock absorber and a swingarm introduced in 1977. The maker called it Mono-Cross (MX for short).".
The reference is under the "Yamaha DT 125R 1991-1992" section.
www.autoevolution.com/moto/yamaha/dt/
Another thought that crossed my mind is the side panel decals for a 1978 DT175MX say "ENDURO 175" not "Motocross".
Owing to our geographical locations, it's possible when I search the internet the results I get are more UK/EU based.

The first ad posted is from a US magazine from what I can see.

The second is definitely from "Oceania".

I'm looking at and for evidence from the initial introduction in the Euro/UK market that decided to use the "MX" suffix...  it is very possible later on Yamaha marketing connected "MX" and "mono cross"... even if it wasn't the initial marketing idea.   

I will try to post some examples of circa 1977 marketing from the Netherlands importer that identifies the models as "MX".  They don't even mention "mono cross" once that I could find...  yet they do repeatedly mention "moto cross".  That's what I'm basing my theory on... 
 
And it doesn't really matter that much at all...  I'm not saying you're "wrong" Pete...  monocross was a great innovation and there is evidence that later on Yamaha possibly did equate the MX and monoshock terms... I just haven't seen it during the initial monoshock "MX" model introduction marketing. 

Some interesting info:
global.yamaha-motor.com/stories/offroadmania/ch3/