Give Me Cool Destinations in Mexico!
 

I plan to ride from Louisville, KY to Mexico City in July. I have very few ideas of what to see while I'm there or along the way. I know I want to see the pyramids and maybe a volcano. I'm sure there are plenty of cool things in Mexico City, but I don't know what they are yet. It would be awesome to see some cenotes, but I'm not sure I can fit the Yucatan in timewise. I only have a month and I don't want to spend all of my time in the saddle

Are there any other things in Mexico that I should add to my list?

Baja, Copper Canyon, all the «Silver cities» along the mid part of Mexico from Durango and south, Zacatecas, Aquascalientes, San Lois Potosi, San Miguel de Allende, Hidalgo etc etc. Also Guadalajara - second biggest city in Mexico is interesting as is Puebla. The most impressing pyramids are maybe those in Teotihuacan just northeast of Mexico city (there are many others too btw)
Oaxaca and San Cristobal de las casas in the south were also beautiful and interesting cities as well.

Snakeboy knows of what he speaks.

Personally, I think with only a month, and having to get from Louisville to the border (I recommend Prisidio for small-town ease), you might concentrate on the NW part of the country. Like just a couple of different descents into the Copper Canyon. It will be UNFORGETTABLE and if the R/T "transit" to Mexico costs you 6-8 days, you will still have enough time to sit on a veranda with a tequila or other intoxicant in Batopilas and get to know Mexicans and the unique Tarahumara Indians who have lived in that area since they fooled Cortez. In would not try to get down to central Mexico in the time you have.
The "longest single thread award" ever is "Is Mexico Safe" on ADVrider where the regulars know everything, past and current, about going down there.
Just don't be in a hurry!