If you need to accomplish auto repairs to your Derbi GPX 1 then it will always be recommended to have a Workshop Manual to use as reference if you want to know tips on how to take out a particular component for instance the Brake Discs and install it again in the correct manner.
Derbi GPX 1 Workshop Manuals offer you targeted diagnostic guides on your car so if something is wrong it can help you find out what the problem is and tips to resolve it. After that you can assess if this can be done yourself or in the event the job is too big it is possible to book your GPX 1 into a local garage.
Derbi GPX 1 manual