Design of the DT1. Well what do you know?
I replied to a picture on Instagram  and got a reply to what I said about the DT1. It reads :
" I love to read praise about the DT1. You may or may not know this but  but my Dad,Niel Fergus, was only one of three Americans to produce a prototype which became the Yamaha DT1. 
Jack Hoel and Dave Holeman were two Yamaha employees who worked in the new product development division. They brought my dad in as the expert rider and expert technical advice and  develop several prototypeswhich resulted in the final production model."
 A great story I thought I'd share and told him I was going to do. His name is Doug Fergus.

Thanks Dave.

I trust that you asked him if he had any of the prototypes or first production bikes secreted away anywhere?!

“Six degrees of DT1” ...This sounds like a new version of the “Kevin Bacon” game 

Badgers 52,You've lost me on that one. What you saying?

en.wikipedia.org/wiki/Six_Degrees_of_Kevin_Bacon

I'd be interested in hearing Enduronut's version of the DT1 development... I always thought a lot more racers like the Jones clan, Mike Patrick, and other So Cal racers had a lot to do with taking the prototype Japan sent over and turning into the DT1? Would be interesting to hear who all was involved, etc.

I finally found a statement I read years ago about Neil Fergus and the DT1....  it's on an AMA racer page where people can post biographies. 

Full version here: thebannerisup.district37ama.org/alumni/nfergus-bio.htm

From this version, it sounds like Yamaha didn't listen much to Mr. Fergus and that he didn't have a very high opinion of the DT1?  I'm not sure either of those things are true? 

"In 1967, future "moto-journalist" Dave Holeman was working for Yamaha International at their Buena Park, Cal. location. He had convinced the head of R & D, Jack Hoel to go out to a desert race and see what fun everyone was having. (As you may remember, at that time Yamaha didn’t make a "real" dirt bike.) They returned and decided that Yamaha should introduce a bike that would work well in the dirt and also make it street legal. Dave & Jack set about to develop a prototype. Once they did, they called Neil because, as I mentioned before, he was known through out Southern Cal as a MOTORCYCLE GURU, and especially a frame and suspension expert. Neil helped them develop the bike through 3 or 4 prototype versions. After each prototype was shipped over from Japan, Neil would ride it and make recommendations on how to improve it. At one point, Neil thought the prototype handled so bad- it was going to kill someone, so he took a cutting torch and cut the steering head off so there was no way anyone could ride it! Evidently the factory was in a hurry to get the bike to market and released a production model to the public without implementing the recommended changes!As you may remember, it was a scary handling bike and it took years for Yamaha to work out the problems with the frame & suspension. So now you know THE REST OF THE STORY- of how the Yamaha DT-1 came to be."

(emphasis added)  The part that makes the least sense to me is if this team of Americans developed the first prototype, why wouldn't Yamaha use it?  It seems that maybe instead of developing a prototype they were doing some testing for Yamaha?  It also doesn't make sense that Yamaha didn't implement recommended changes...  or that Yamaha rushed  to release a dangerous scary handling bike that somehow ended up being so popular?

(The article does go on to mention Mike Patrick...  who I was lucky to meet personally...  he owned the Yamaha dealer where I grew up... met him as a kid and he was always nice when I went there to look at the bikes with my Dad...  and I met him again later in life when he had a small auto smog test shop.  Great guy.  I didn't have the foresight or knowledge of his involvement to talk to him about the DT1 but I do remember him and his wife talking about racing the big British bikes in the 1960's desert before going to Yamaha...  his wife (Annette?) taught me some of the funny names the British had for parts like "gudgeon pin" when I was about 10 years old.  She eventually opened a small clothing department where I got my first "leathers" when I started racing at about 15)

If would be nice if someone had the actual facts instead of "recollections" that often aren't exactly factual. Enduronut might be that person with regards to the DT1? 

I'd be interested to know too.

Shyted ... Sorry for the confusion. As I was read your post and followed the different layers of the DT1 development; it reminded me of the once popular Kevin Bacon game. The game was based on a 1930’s mathematical calculation to test a Six Degrees of Separation theory that now explains how things can go viral so quickly.
Starting with DT1 (level 1)
to Niel Fergus, Jack Hoel and, Dave Holeman (level 2)
to Doug Fergus (level 3)
to Shyted (level 4)
to all the group members that liked your post (level 5).

This group is a good example of how quickly people with common interests can quickly get together. This article sums it up better than I ever could.

exploringyourmind.com/the-six-degrees-of-separation-theory/

soo .... then...
I'm Kevin Bacon?