How do you figure out the transfer time of a cylinder?

CHS (Cylinder/Head/Sector) geometries really don't apply to modern harddrives (at least from an enduser standpoint), but for the sake of argument let's assume they do. According to Wikipedia, a cylinder is defined as:
Let's futher assume that by "transfer time of a cylinder", we're interested in the amount of time it will take to read, and transmit, all the data in each block in a given cylinder. So, our definitions:
Because we only need to move the heads once (by definition, all tracks in the cylinder require the heads in the same position), the time to read the data becomes:
Now, we need to figure out the time to transfer that data. Given a transfer speed of x bytes per second, and a data density of b bytes per cylinder, the time to transfer (including the time to read the data) will be:
Now, to determine an actual transfer time, you'll have to plug in the numbers for x, t_{seek}, and t_{track}, which will all be device dependent. Even b is device dependent, since modern hard drives don't report their real physical geometries and actually cram a lot more than 63 sectors onto a track (the number varies with the track position  more near the edge, fewer near the spindle). We can make some other observations (about exactly how to calculate t_{track}, which will vary based on the location of the track on the platter), but for general purposes device dependent will suffice. 

