I just do not see the improvement with the yamaha front forks.
You still have telescopic front forks and single disk brake.
I bought that exact bike the first week it was introduced and was racing dirt track motorcycles (not the 400F-4), at that time and I rode my 400F hard on the street and it handled very well with the stock front forks.
Question...Why do you keep giving measurements in mm's?
Are you from france?
"As an example, a bike with a front tire having a circumference of 1890mm."
That would be 74.4 inches circumference.
Makes no sense. Diameter is what is needed
" a 23-degree rake and 27mm of offset will have 98.5mm of trail. Note that in the range of variables we are dealing with"
That is 3.87 inches of trail. = 98.5mm
But why throw in the offset? The offset of the bottom and top triple tree are the same.
With less offset the rider just has less leverage over the steering .
I just do not see the improvement.
Matter of fact these modern sportbikes have such steep rake that they all have to have steering dampners now. That is NOT an improvement as far as I am concerned.
Some Suzuki's now only have 24º of rake!! Crazy.
The stock bike CB400F
rake/trail/and wheelbase
numbers that were not seen
before or after: 26.5 degree rake,
3.346 inches trail, and a short 53.5”
wheelbase.
26.5º was seen as very steep rake at that time.
The most successful racing motorcycle ever designed had about 29º-30ºrake.
It was the XR750 H-D.
Matter of fact in the last 6 months almost all references to the measurements of the XR750 frame have been removed from the internet due tho the fact some people started to copy that frame design.