No, not usually. The fronts are a completely different size for the width rim you have now, and if you do find rear R1's that would fit your current rims, they'd most likely be too tall and throw off your front/rear ratio in the trans. JD uses/d 14.9 x 24 and 13.6 x 28 R1's, while your R4's should be 17.5 x 24's.