If you need to perform repairs for your Hyosung RT 125 D then it is always recommended to have access to a Workshop Manual for a guide in the event that you want to know the way to take out a particular part including Brake Discs and match it again properly.
Hyosung RT 125 D Workshop Manuals will give specified diagnostic guides for your car therefore if something is broken it can help you understand what the issue is and tips on how to make it better. Then you are able to evaluate if this can be achieved yourself or if ever the job is simply too big you can book your RT 125 D in with a suitable garage.
Hyosung RT 125 D manual