Greg Harding wrote:Hi Everyone,
Interesting, I assume all of you realize that there are purists who only beleive in concourse del elegance and the manufacturer got it perfect in every way!
I dont know what the Yamaha engineers or Mick Andrews (still a legend anyway) were thinking when they made and endorsed the TY175, but the biggest fundamental flaw in the swingarm design in my opinion is the axis or pivot point of the location of the swingarm bolt. Having it rear set of the bottom frame loops and close to the footpegs allows no progressive leverage. They inset mounted the swingarm on the TY250 and all the DT's also, when there is just enough room to do this mod carefully anyway. This would lengthen the swingarm somewhat also, and would need stiffer springs. Also having the countershaft spocket closer to the pivot is usually the norm on most bikes anyway to lessen chain loading and wear.
Just look at a modern bike to compare how far back the pegs are to the pivot point,but then the linkages in the shock are progressive also.
I did a comparison with a DT175 swingarm to the TY175, its way too long, heavy and shock mounts wrong. Nothing like it could not have been an achieved mod back in the era, using like available era parts??