550 rear tyre size

[Valentinik]

I'm about to order the tyres for my 550k3. I like the classic look tyres so have decided to go for metzelers. Me11 on the front and me77 on the rear.

Which tyre size would be preferred for the rear.  I have the choice of 4.0 x18 64 H which I presume is tubeless or 3.50 x 18 56 S.

Is the 3.5 tyre wide enough for the rear? Also, would the tube tyre be better than the tubeless or can tubeless tyres be fitted with tubes?

Thanks
Mike

[Valentinik]

Thanks oddjob. The front rim is 1.85 x 19 and the rear is 1.85 x 18. They're the original spoked rims

The front tyre I found was 3.25. Would the 3.50 rear tyre match with this? I quite like the narrower look but I don't know it is too narrow for the bike?

Sorry if these are simple questions, I'm still learning as I go along 

Thanks
Mike

[Valentinik]

Thanks for the help oddjob, I went with the 3.50 rear.

Thanks
Mike