Mechanical disc rotor for CUBE MTB - front wheel : Shimano 559x17-21c Seeking advice with regards to the size of disc brakes for front wheel.

Cube mountain bike. Front wheel: Shimano 559x17-21c. Disc brake: Shimano brake disc sm-rt 10 Centre Lock 160mm



Could you kindly advise - would a 160mm brake disc be suitable for a cube MTB - front wheel size- 559x17-21c I do not have a picture of the bike at present, if necessary I could get it and send it later.  Not sure of the model either.

Many Thanks,

Tam
As you wrote, your bike already uses 160 mm Centerlock disc at front. If you need a new disc instead of worn/damaged old one, any 160 mm Centerlock disc will be compatible.

There are some concerns about certain brake pads types not being compatible with all disc types, but in my opinion it does not matter, all pads just work with metal discs.

Do not go with different diameter of discs unless you experience lack of stopping power. If so, bigger 180 mm discs may be an answer, but you'll need to check if they are compatible with your fork and won't break bicycle warranty. Besides, an extra/different adapter is usually needed to install a disc of a different size.