I ride my 01 YZ426F primarily on tight single track trails. The grab handles yamaha put on the 400s and 426s are the best design I have ever seen. Love being able to easily yard the bike out of a rut or turn it around on a hill with them. I am considering doing the 03-05 450 body mod, but not if the functionality of these handles is compromised. The 426 ones you can get a full grown man's hand into with ease, no sharp corners really, and you are basically pulling right on the subframe so it doesn't stress the plastic much. How are the handles on the 450 in comparison? Wish I knew someone that had one so I could just go see for myself!