aviator, you must be hi....
First off, there are speed restrictions per altitude and sectors around an airport regardless of the procedure. There is a multitude of reasons for a speed restriction, and now we are even using speed restrictions on departures. (to prevent your nose from implanting on the others butt)
The speed restriction is based on a max bank angle of 18 degrees in a turn. This based on not exceeding 25 degree bank angle, with 5 degrees for course correction in the turn, as for many aircraft, the limit is 25 degrees, and for others the max is 20 degrees, etc or the system will not allow an increase in the bank angle, and will roll out of the turn. (according to the FAA 25-5=18
)
The design includes winds, with the FAA using the max wind as a tailwind all the way through the turn. You will know when the procedures is a multi-variant turn (including A380, 747-8) when the radius is about 6nm!
So as you can see, if there is a turn with a max speed of 185, if you are going 100, you will have a very low bank angle, whereas if you are at 185, with a tailwind, you may be closer to 20 degrees.