hey HBJ, if you use WinRAR to make archives is pretty easy to split the files in smaller chunks.
1. Select the folder you want to compress, right-click and select "add to archive".
2. now the WinRAR window should pop up. Select "RAR" insead of "ZIP"
3. in the "split to volumes, bytes" section you can select from the presets (the Zip100 - 100 mb chuncks - option is the most common) but also you can set any value you want, in this format: value followed by "mb"
EX: 200 mb - 200 mega chunks
250 mb - 250 mb chuncks
etc
Hope you understood. My english sucks
If have any other questions don't hesitate to ask, maybe i can be more explicit
Andrei