I worked in one bike i adjust the brakes and the gears but is do weird shift The RD. Is up shift fine the RD in all ten cogs but when i down shift all 9 cogs downshift very smooth but when i downshift before the chain go in the smallest cog is do like skip then go on the smallest cog. The chain is looks good. The RD is tiagra is can be RD problem or somethink else.