hello! need advice...

[rockhopperRaf]

Hi all,
I have 2007 specialized rockhopper widh shimano (deore) groupset, i recently got fast road rear sprockets (fitted professionally as i dont really know my way around bikes yet ) every thing is ok, but I get pedal vibrations in the fastest gear, Could anyone help me and educate me what it could be? many thanks

 

[kdelong]

Possibly chain rub on the front derailluer cage. Take the bike back to whoever changed the cassette for you and have him adjust the FD. This is a standard pat of the procedure that he might have missed. If it turns out to be something else, he should have caught it and let you know about it when he tested his work.

 

[rockhopperRaf]

Thank you for your reply...I just wanted to have some info on that, so that I don't get ripped off in the shop...
all the best...peace