Ive had a bit of play in my rear wheel (lateral movement) so though id check out the bearings. took the axle out and checked the cones?? which look slightly pitted so will be replacing them along with the Bearings. i need more grease but is there any real differnce in ball bearings? im taking the old ones into the shop to get the right size but is there any differnce and what types of bb's can i get??