Converting womens' road bike to flat bar?

I bought my wife a Cannondale Feminine Synapse Carbon 5 road bike and she hates the handlebar. Sheasked that I convert it to a flat bar - requiring different bar, brake levers, shifters and the like. My question is: do I also need to trade out the rear and front derailleurs to work with the replacement shifters on the handle? What about brakes?

If her bike is equipped with a Shimano drivetrain, there should be no need to change out anything other than the bar, shifters, and brake levers as long as you replace them with Shimano. I did this for my girlfriend. I cannot say if this is true about other brand components but it probably is.You might also consider checking out a new stem, possibly one of the ones that has the adjustable angle so that you can fine tune it to what is more comfortable for her. Oh yeah, you will most likely need to invest in some new cable assemblies.

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shimano makes flatbar shifters that are compatible with the front derailleur. The rear doesn't care.

If you use a MTB set of shifters, then the FD will not be compatible and a MTB one may not match the crank well. Just look at the road, flatbar shifters from shimano.
SL-R770 is the model number(10s)