Hi all, could someone please tell me the width of the rear rim for a 72 TS250? I am preping the bike to run in a hill climb and am trying to figure out my tire options.  The markings on the rim look like it says 18x185B so I would think it is a 1.85in rim?  The outer width is almost the same as a 2.15in rim I have from a RM so I just want to be sure.  Also if anyone has some common tire sizes that fit or a tire suggestion I would be happy to hear them.  I was looking at some 110-18 tires but am worried they may be too wide for a 1.85in rim. 
Thanks!