01-09-2011, 05:26 PM
there def different. the zx6rr was built because the 636 couldnt not legaly be raced in the ama 600cc class... there is alot the same about the 2 but there are differences in the powertrain. they didnt want the bike to be faster than the 636 but they didnt want it to be slower either cause when it sold new it cost more money.. basically the zx6rr was a lil more track ready where as the 636 was more there street flagship 600cc model. im not sure all the differences in the 2 but i know there was alot. at least in the 05 06 models.