If you have to accomplish fixes to your Derbi GP1 50 Open then it is always a good idea to have access to a Workshop Manual to keep just for personal reference in the event that you want to know techniques to take off a specific part like the Wheel Bearing and fit it again adequately.
Derbi GP1 50 Open Workshop Manuals gives you particular diagnostic guidelines for the car so if something is not working it helps you determine what the issue is and tips on how to repair it. You can then evaluate if this can be achieved by yourself or if ever the job is simply too big you can actually make a booking for your GP1 50 Open in with a nearby car garage.
Derbi GP1 50 Open manual