I am curious to know what the main differences are in Avid's vbrake lineup? Which one would you recommend for the rear? I am currently using a HS33 on my zebdi and am curious to see how a vbrake will work. I have a SD3 on the front with a dogpoo old shimano lever and it works so much better than my maggie ever worked. I think I should also add that I am a competant bike mechanic so I am sure I have set them up proper. I am currently just using stock pads with a grind. I think tar on an ungrinded rim worked much better. Any opinions on the above questions would be appreciated!