Rear Wheel + Knobbies

[Allissa Subasavage]

Hey guys. Xs400sg looking to put some knobbies on it. Have 18 up front and 16 on back. Bought 18 rear wheel off a 750 (for the wheel since had a hard time finding 16 knobbies) but doesn't work. Which wheel can I use?

 

[NewHavenMike]

I have spoked wheels but my bike is a 76 xs360. both 18"

 

[Allissa Subasavage]

I was hoping to avoid spokes

 

[Ethanl]

my 83 dohc has the 4 spoke syle and has an 18 rear

 

[xschris]

The 77-D the 78-E and the 79-F used a 18" mag rear wheel but it's a disc brake. Some euro xs400 bikes came with a 18" rear mag with drum brake but very hard to find a shipping would be crazy.