Riding a bike shouldn’t hurt. If it does, something is wrong, generally with your fit, gear, bike setup or riding style. With all those moving pieces, deciphering just what’s gone awry can be tricky. That is why you need a solid movement assessment to find out what is the main culprit

3. Low back Pain
Common culprits: Saddle too high or too low; poor core strength; mashing gears and/or too much differential between your saddle and bar height.
Try this: First check your position. If your hips are rocking side to side as you pedal, your low back is taking a beating—lower the saddle until they’re stable. If it’s too low, your knee has to come up above hip level at the top of the pedal stroke, which also can flex and stress the low back. Next check your posture. You should aim to have a flat back with normal low-back curvature. If your spine is rounded, you’re stressing your back. Roll your pelvis forward to create a neutral spine. Adjust the cockpit of your bike to maintain that position. Often that means bringing your handlebars and saddle closer to level with each other.
4. Hip/Groin Pain
Common culprits: Saddle shape and/or saddle position.
Try this: A saddle that doesn’t fit your anatomy will be uncomfortable no matter where you sit on it. So the first check is that your saddle supports your weight on your ischial tuberosities (the hard bones you feel when you sit down) or the pubic rami (the pelvic bones further forward) not your soft tissue. The saddle needs to be level. Nose down or nose up can shift weight and cause problems. Finally, too much reach to the bars can cause you to roll your pelvis forward and place weight on your sensitive tissues. Tighten your cockpit with a shorter and/or more high-rise stem.
5. Knee Pain
Common culprits: Saddle height and/or cleat position.
Try this: Follow the old adage: If you have pain in the front of your knee, your saddle may be too low. If you have pain in the back of your knee, it may be too high. IT band pain in the knee (stabbing pain in the outside of the knee) may also be from a saddle that’s too high. However, a really common and often overlooked source of knee pain is cleat position. Cleats too far forward or too far back can stress the knee joint. Also check that you’re not pedaling toe down, but rather with a proper heel drop, so you use your calves as stabilizers and generate more power from your glutes and hamstrings, all of which remove stress from your knees.