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I tested a Cannondale Optimo 4 (entry level road bike with Claris) and I liked the bike but had 1 issue. When I shift to biggest wheel in front and small wheel in back there is a grinding/rubbing noise. There was no cross chaining. The salesperson said that I need to shift the bike to the high gear in the front and then do a small shift in the other direction to adjust the derailer front position to stop the possible rubbing.

Is this normal or can I adjust the derailer position by using a screwdriver to not have to do this microshift in the opposite direction every time?

Biggest ring on front and smallest in back my bad so there is no cross chaining but apparently still need to "trim" for some reason.

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  • Do you mean, when you shift into the big chainring, there is a slight "overshift" which you then have to trim back, in order to stop part of the front derailleur cage from rubbing with the chain? Does it happen every time you shift into the big ring, or does the chain position on the cassette make a difference?
    – SamA
    Commented May 1, 2023 at 12:32

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I think I figured out the issue, the front derailleur was not parallel to the chain and the front part of the derailleur was hitting the chain while the back part was far away from the chain.

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  • First steps of a front derailleur set-up are height and alignment/parallelism with large chainring. Good job noticing the misalignment.
    – Jeff
    Commented May 5, 2023 at 2:12
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Though normally you go to the smallest cog only after you shifted to the big ring, what you experienced is a classic example of an improperly adjusted or aligned front derailleur (and a salesman selling snake oil). There is absolutely no mechanism to trim the front cage position by going through the cassette in a mechanical setup.

This is a very common problem. Most bike shops will not follow the procedure to correctly install and align the front derailleur because - although simple - it is quite time-consuming. Instead of doing it by the book, it's usually done in a less strict fashion which sometimes results in problems like yours. I've seen this in bikes of all price ranges - not only entry-level where price cuts are most likely.

Thus, the way to go is to do the adjustment yourself. You can download the manual directly from Shimano's website which will guide you step-by-step through the entire process.

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