Just took my Trek 6300 bike to Evans plymouth city center for silver service and replacement of chain and cassette,for a grand sum of 150 pounds. . Got bike home and noticed that it makes a crunching noise as I cycle along using the middle chainring. I have inspected the middle chainring and noticed that there is obvious wear to the teeth,quite understandable as this is the most used ring out of the three front ones.. This should have been noticed by the so called experienced service technician when replacing the chain and rear cassette and so they should have informed me of this and fitted a new middle chain ring. I have now had to source a new part so I can fit it my self and now I am without a bike for a few days. If I had continued to use my bike in the condition Evan cycles had returned it I would have caused more damage to the new fitted parts.