Absolutely perfect!!! Had to do this exchange for non-bowden MK8 long time ago, because non-geared extruder has really not enough strength. Bowden + gear is the only reliable solution, adding strength and solving problems with extreme temperatures affecting the filament.
I made a little changes in the solution - I used 608 bearings + inserts to make them bigger. I also used 12mm threaded rod, but making them to 8mm at the ends to fit into 608 bearings. 12mm shaft is really transferring more force to filament than 8mm. Rod was taken from an old printer.