My thoughts are, and keep in mind I'm pretty new to all of this, you should spin somewhere between 80 and 100 rpm. If you like to spin at 90 then falling below that for any length of time would constitute mashing for you so you should shift down to an easier gear and bring your cadence back up to 90. But remember, on some steep, long hills you will not be able to keep your cadence up to a normal level.

Ladies, am I pretty close on this one?