Removing acceleration/deceleration from pitch MPU-6050

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This is a great library to work with.  Thank you for putting it together.  

I am looking to measure the pitch of a vehicle (I'm using a bicycle).  While using the DMP-6 example code, I get the pitch; which, is great under static conditions. Unfortunately, when I apply the brakes, accelerate, or just move, the pitch will increase moving forward and decrease while braking.

Do you have advice on how to compensate or remove the acceleration from the IMU to get accurate values like the static condition?

Thanks