The CR/CRF fork uses a bigger gearing. Emig Racing makes a stem that fits the smaller XR bearing while still being thicker than a machined down stem. The XR bearing is quite a bit smaller so I don't know how a CR/CRF stem could be machined down enough and still be strong enough. My set up consists of 05 CRFr forks,front caliper and master,wheel and 07 CRFx triple clamps, BD 8" race light. Combination of friends with extra stuff (free or cheap) and e-bay buys. The valving is stock. I haven't even ridden it in the dirt yet. Seemed OK so far on the street/ hi-way (has a plate)...
Steve in SF
87 Harley FXRS-SP ~ 06 KTM 625 SMC ~ 72 Honda CB750/915cc ~ 92 XR600/654cc ~ 95 XR650l/675cc ~ 03 CRF450r ~ 05 CRF450x ~ 02 XR650l/675cc ~ 86 YZ490 ~ 93 YZ80 ~ 93 XR650l Project