Road bikes: If the bike has a traditional straight top tube that is parallel to the ground, you should have approximately 1" of clearance between the ground and tires when you lift the bike as you’re straddling it.

If the bike has a sloping top tube (semi-compact or compact design) expect to have clearance of 2" or more. Both men’s and women’s bikes can have compact frames.

Mountain bikes: When you lift the bike, you want 2" minimum clearance between the tires and the ground. If your bike has full suspension, it’s okay to have less initial clearance (1"–2") because the suspension compresses under your weight once you sit on the bike. That said, the amount of clearance is largely affected by the slope of the top tube down toward the rear wheel. For example, if the slope is dramatic, you'll likely have ample clearance no matter what size the frame is. Because of this, you can't rely solely on standover clearance to determine if a bike fits.

Hybrid bikes: If your hybrid bike is a city commuter, use the road bike guidelines. If it’s a beach cruiser or a step-through style, you don’t really have to worry about standover height. Most of these have steeply sloping top tubes that let you step over easily and put your feet flat on the ground when seated.

Bike Standover Height: Online Shopping Tips