One person's working-out of standover height, reach, crank length and total weight, after a run of shop test rides and a year of grocery trips. Free to read, nothing for sale, no affiliate links.
Motor wattage and battery capacity are printed in large type on every spec sheet, and they are the two numbers least likely to determine whether a given electric bicycle gets ridden. Fit does that. A frame that is an inch too tall at the top tube, or an inch too long from saddle to grip, produces a bike that is fine on a demo loop and quietly unpleasant on a Tuesday errand with two bags of groceries. The measurements that predict this are few, they are takeable at home with a tape and a level, and most of them are either buried in a geometry chart or absent from it entirely.
Standover, measured against your actual inseam
Standover height is the vertical distance from the ground to the top of the top tube, usually quoted at the midpoint, and it is the first hard filter. Take your inseam by standing barefoot against a wall, pulling a hardcover book up firmly into your crotch, marking the top edge, and measuring to the floor. Do it twice. Then subtract: on a step-through or low-step frame the question is whether you can swing a leg over at all, and on a diamond frame you want somewhere between one and two inches of clearance in flat shoes. On a fifty-pound bike that clearance is not vanity. It is what lets you stop on a slope without the top tube arriving first.
Reach and stack, not top tube length
Manufacturers still publish effective top tube length, which mixes seat angle into a number meant to describe cockpit length, and on bikes with slack or steep seat tubes it misleads. Reach, the horizontal distance from the bottom bracket to the top of the head tube, and stack, the vertical distance across the same two points, are the honest pair. Together they describe where the front of the bike sits relative to where you pedal. A shorter rider generally wants reach short enough that the elbows stay slightly bent with hands on the grips, and stack tall enough that the bars are not below the saddle. If the chart omits reach and stack, that omission is itself information, and asking the shop to measure the floor model is reasonable.
Crank length, the number nobody prints
Crank arms on most e-bikes sold in the United States are 170 or 175 millimeters, chosen for manufacturing convenience rather than for riders under about five foot four. Long cranks force a wider hip and knee arc at the top of the pedal stroke, raise the minimum saddle height needed to clear the bottom of the circle, and make low-speed starts feel unstable. Measure what you have: center of the bottom bracket spindle to center of the pedal spindle, in millimeters, usually stamped on the inside of the arm. Shorter cranks, in the 155 to 165 range, are widely available and often a modest shop labor charge on a mid-drive or hub-drive bike alike. It is the cheapest meaningful change on this list.
Handlebar width and grip reach
Bar width should approximate shoulder width, measured across the bony points at the front of each shoulder, and a great many commuter and cargo e-bikes ship with bars far wider than that because wide bars photograph well and feel stable at speed. Too wide opens the chest, loads the wrists, and makes tight parking-garage turns awkward. Bars can be cut down by a shop for very little. Separately, check brake lever reach: most levers have an adjustment screw that brings the blade closer to the grip, and a rider who cannot cover the lever with one finger from the grips is not braking as well as the hardware allows. The Consumer Product Safety Commission is responsible for bicycle braking requirements at the federal level, but adjustment for a particular hand is left to the shop and the owner.
How to check all of it in a parking lot
Bring the inseam and shoulder numbers written down. Straddle the bike flat-footed and look down at the gap. Set the saddle to roughly 0.88 times inseam, measured from the center of the bottom bracket along the seat tube, then ride slow figure eights and stop hard twice. Watch for three things: whether your heels drop past comfortable at the bottom, whether your knees track outward at the top, and whether you can put a foot down without shifting off the saddle first. A careful reader checks the chart before the visit and the body during it, and the two together settle the question quickly.