If you choose to accomplish repairs on your Veli VL90 6 then it is usually recommended to own a Workshop Manual to keep just for personal reference in the event that you need to know tips on how to remove a certain part for example the Wheel Bearing and match it again adequately.
Veli VL90 6 Workshop Manuals will give identifiable diagnostic facts for your vehicle therefore if something is broken it can help you identify what the problem is and ways to correct it. You can then evaluate if this can be done yourself or if the job is too big you could make a booking for your VL90 6 in to a local garage.
Veli VL90 6 manual