The road wheels of the PzKpfw I Ausf A were smaller than the prototypes.
The drive sprocket was located in the front, and the transmission ran along the floor to the differential beside the driver.
Five rubber tired road wheels with the last pair being the idler. The front wheels were sprung on coil springs. These were secured to the hull by bolts and quarter elliptic springs. There was also a large idler wheel in the rear trailing on the ground. A steel girder was a reinforcing beam between the last four wheels.
The air-cooled Krupp M 305 engine, and oil cooler were in the rear of the tank. The drive was through a dry 2-disc main clutch to the ZF Aphon FG 35 5-speed gearbox. A few prototypes were tested with the Krupp M 601 diesel engine but it only produced 45 hp at 2,200 rpm and was insufficient.
The welded turret had two 7.92 mm machine guns. The machine guns could be fired separately or together. There was a 2.5 power TZF2 optical site located between the machine guns.
The turret had four vision ports that were covered by armored flaps.
The Ausf A was a fully tracked vehicle with a 2 man crew. The fighting compartment was shared by the commander and the driver. They communicated via a voice tube. There was a door in the left side of the hull for the driver to enter, and the commander entered through the turret hatch. The commander had very limited vision and often stood up, which exposed his upper half of his body. The commander's seat was suspended from the turret.
In early 1933 an anonymous German officer wrote in a military magazine that the PzKpfw I Ausf. A had many problems that it was unusable in combat, and was only useful in parades.