If you want to carry out adjustments on your MZ SM 125 then it is always a good idea to have a Workshop Manual to use as reference in the event that you want to know methods to take off a certain part much like the Wheel Bearing and install it again in the correct manner.
MZ SM 125 Workshop Manuals will give you precise diagnostic wisdom on your automobile so if something is not working it can help you determine what the problem is and methods to make it better. After that you can determine if this can be done on your own or that the job is just too big you could make a booking for your SM 125 in with a nearby friendly mechanic.
MZ SM 125 manual