Originally Posted by Mike sgonre

To determine if you need shorter crank arms, you can consider the following factors:

Leg angle at pedal strike: Are your legs hyperbent or hyperextended when your bike's pedals are perpendicular to the ground? If yes, you might be more comfortable with shorter crank arms.

Flat vs. uphill difficulty: If you're struggling with uphill or you need to use more force to complete the climb, shorter crank arms can make the climb easier.

Comfort: If you experience discomfort in your knees or other joints, it may be because your crank arms are not the right length for your body size and proportions.

If you're not happy with any of the above, you can try shorter crank arms to see if another length works better for you. It's best to consult a professional bike mechanic and ask them to help you measure the crank arm length you need as it will depend on your body measurements, seat height and pedal style etc.