Head tube angle is the angle of the front tube on your frame relative to the ground, and it shapes how your bike steers and handles. Steeper angles (73–74°) make the steering quicker and more responsive — you'll find these on race-oriented road bikes built for snappy handling. Slacker angles (71–72.5°) slow the steering down a touch, adding stability and confidence, especially on fast descents — typical of endurance road bikes.
Most road bikes fall between 72–73.5°, which balances responsiveness with control. If you're a competitive rider who values quick direction changes and a nimble feel, lean steeper. If you prefer stable, predictable steering for long days in the saddle, go slacker.
Don't fixate on this number in isolation, though. Trail and fork offset also influence steering feel, so two bikes with the same head angle can handle differently. And don't assume steeper is always better for racing — stability matters at speed. Prioritize getting your stack and reach right first, then compare head angles for handling character.