I am looking at belt driving my ballscrews in order to contain the steppers within the footprint of the machine and to have the option of gearing down the drive on the X and Y axes. Using this arrangement there is obviously some lateral force on the pulley and therefore on the bearings too; is it necessary (or just preferable) to use angular contact bearings or will the standard BK/FK bearings be sufficient?

I've really searched but I can't seem to find a definitive answer - I'm guessing I can't be the first to ask this though.