I did two USD fork conversions, the first using an Emig custom stem and CRF450 parts and the second with custom bearings and CR250 forks, both were excellent improvements over the standard forks and also allowed for the fitment of fatbars.
- beautifully machine stem
- lock stops need to be removed from the lower yoke
- Emig stem requires original stem to be pressed out and new one pressed in plus a bush in the top yoke
- old steering lock needs to be removed
- new lock stops – I used 5mm aluminium plate
I found some bearings that would fit so bought and fitted them, they required a spacer for the bearings as they weren’t as tall. Made my own spacers, good to go.
These days just go to All Balls Bearings and look at their fork conversion page.