For a long amount of time I had been annoyed that whenever I recorded gameplay with Fraps, the framerate would become unplayable (<15 fps, 1920x1080).
The simply solution? Downgrade to a previous version of Fraps! I obtained an older version of Fraps (Fraps v. 3.3.0) and tried recording and it seemed to work beautifully.

Just remember that Rage is already very demaning on the processor, so you'd need a really high end CPU to record 1920x1080 at 60 fps (eg. i7-2600k, i7-980x ...).
To reduce the strain on the CPU when recording, decrease the resolution of the game to something lower (like 1280x720). The "Half-size" option in Fraps will not work, as it just uses the CPU to scale down the image to half the resolution to decrease strain on whatever harddrive you are recording to.

Also, you'd preferably record to a different drive than the one where Rage is loading the megatextures from (specified by the "vt_filePath"-command, the default setting is the same folder/drive as the game is installed on).