If I need to change my rear tires due to wear, is it ok to just change the rears. Or do I have to change all 4 tires? I mean changing to a different brand of tire as well.

 

you can do the rears only, as long as you do both.

you can change brands. if you have different brands front-rear, i guess it is ok for a while...just don't go tracking.

 

I think the only real issue would be the rating on the tires and the "stickyness." So if you get different brands for the rears but they are the same type (rating/stickyness) as the front then it should be okay.

 

I'm thinking about doing this myself as I have SO3's; I am probably going to replace the rears with RE750's.

 

i just put 750's on the rear today. The 730 and 750s were on my GSR and they were great, and they last a good long timem about 20K.

sure, they don't have as much dry grip as the S02s (not by much) but the wet grip is a lot better and they last >2x as long.