I only think about riding and discovering great places like my signature says. Not everyone wants to do the wrenching, although I've done a little as needed, and have changed tires several times. I feel that greasing is better done by the professionals. My question today was asked to try to delve into what is really going on inside those bearings, and I did read most posts in this topic before asking my question.Not everyone can wrench on their own machine. Disability or maybe they don't store it at there own home, time is money so maybe someone makes more money with their time etc. Heck or maybe someone has wrenched on their machines their whole life and if they can afford it then why not pay someone else to do the dirty work.