larger rear tire

[CA200_imp]

I think one thing to keep in mind here is that our bikes have radial tires( even though they are a odd size) . I don't see anything
wrong with putting bias tires on but you might have a rougher ride. Switch both.
Radials deform more when you put them on to small of a rim. So you get more strange handling issues.
Most of the tire Mfg. making a 160/60-18 in a sport touring tires are making it to fit a whole group of older late 90s BMWs.
They all had 4.5" rims on the rear. I mounted a lot of them.
I am very proud that in the last year my store was open ( 2012) I mounted right around 1000 tires myself. It was nice to go out
on a good note.