If you want to carry out adjustments to your Veli VL150 11 then it will always be recommended to have a Workshop Manual to keep just for reference just in case you need to know how to remove a certain component for instance the Brake Discs and fit it again accordingly.
Veli VL150 11 Workshop Manuals are able to offer special diagnostic info for your vehicle so if something is playing up it can help you ascertain what the problem is and tips to make it better. After that you can analyse if this can be done yourself or if ever the job is simply too big it is possible to make a booking for your VL150 11 in to a suitable garage.
Veli VL150 11 manual