Re: KH24 tiawan+ profile wheelset
Dont grind anything on the frame!!!
There is no need to grind anything to be able to fit a Profile hub in the frame.
If you have a Taiwanese KH24 frame then you’ll need to shim up the bearing holders to fit the Profile bearings. Read the link that Tom Blackwood provided for more details. Also, contact unicycle.com to find out if they have any custom shims for the bearing holders. If they don’t have shims you can use a soda can to make a shim.
Unless you are talking about grinding the flying saucer shaped spacer that Profile supplies. That spacer can get in the way and grinding it down would improve clearance. I actually don’t use the flying saucer spacer and instead use extra aluminum Profile washers instead.