Named after the Roadman brand of sports bicycles from Bridgestone but with no apparent license, Cycle Race Roadman: Gekisō!! Nihon Isshu 4000km is predictably a bicycle racing game. The race in this game is a multi-stage race around Japan. You start the game choosing a team out of 4 - USA, France, Italy or Japan - and then choose a biker among the 5 bikers of each team. Each biker has his own stats.

The race is viewed from a top down perspective. Pedaling is done manually in this game and each time you pedal, your biker loses some Power. Your maximum speed is capped at each biker's individual Speed stat. Continuing to pedal when you have reached this cap only consumes Power and yields no acceleration. You must restart the current stage if you exhaust all of your Power. Your bike also has a durability which is worn down as you race, and drops faster if you collide with the track boundaries. If your bike takes enough damage, you must wait for a support car to bring one of the bikes from your team's inventory to continue the race, during which your stage time does not stop counting. Colliding with an opposing biker will result in either one crashing or both, depending on the collision angle. A crash also damages your bike's durability. You cannot collide with your teammates. Instead, by approaching your teammates, they will randomly give you powerups which instantly restore your Power, repair your bike or accelerate your bike.

Your biker is influenced by wind which changes direction frequently. Steering in this game is not fine-grained. Pressing left or right will instantly rotate your bike by 22.5 degree, and your maximum steering angle is 67.5 degree.

Inbetween stages, your performance in the previous stage will be converted into points to buy new bikes to add into your team's inventory.