If you want to undertake maintenance for your Derbi Senda SM Racer then it is always a good plan to own a Workshop Manual to keep just for personal reference if perhaps you want to know easy methods to take out a certain part for instance the Wheel and match it again the right way.
Derbi Senda SM Racer Workshop Manuals will give particular diagnostic guidelines with regards to your car or truck therefore if something is broken it will help you work out what the situation is and how to resolve it. You can then assess if you can do this on your own or that the job is too big you can still make a reservation for your Senda SM Racer right into a decent mechanic.
Derbi Senda SM Racer manual