SKF is an excellent quality german bearing, the best. NTN is an excellent japanese bearing, likely just as good. The Allballs bearings are definitely chinese. Inferior to the first two - you can feel and see the difference in surface finish. I personally wouldn't run them as a high speed bearing (crank etc) but in a stearing head they would be fine, other than any seal issues. The only advantage the Allballs have (other than price) is that they make kits the others do not, plus lots of metric oddball sizes that help when doing fork swaps or other custom work. Bearing wholesalers are in your phone book yellow pages under "bearings". I have BC bearing and KAMAN bearing nearby. The races in the steering head pop out quite easily. I doubt it would be possible to oval the head doing this. My CBR900RR ones (alum frame) came out the same as steel framed ones. Just use a long punch with a good end (not rounded). The stock KX bearings are good quality japanese bearings in std sizes. They can be matched up to SKF/NTN . I did 4 steering heads last winter so I am up on the topic, 2 allballs conversions, 1 fork swap and 1 straight replacement. Hope this helps. Cam.