Bike Pedals In Both Directions, Gets You To Your Destination AND Back

[punamenon2] has built an interesting bike that moves forward regardless if it is pedaled forward or backwards! What? Yes, you read that correctly. Pedal forward or backwards and the bike goes forward. This project started off as any old cruiser with a free-wheeling rear hub. To pull off this mod a second free-wheel and sprocket had to be added to the current wheel assembly. One free-wheel and sprocket set is used when pedaling forward, the other set is used when pedaling in reverse. There is also a new chain tensioner that serves to not only keep the chain taut but also allows for the chain to change directions which ultimately allows this novel idea to work.

Confused? Here’s how it works:

When pedaling in the forward direction, the bike acts as a normal bike does where top of the Crank Sprocket pulls the chain and the chain then pulls on the top of the Large Wheel Sprocket. This turns the rear wheel in the forward direction. The portion of the chain that wraps around the Small Wheel Sprocket is traveling in the backward (CCW) direction which doesn’t cause a problem because it is a freewheel, just like how you can pedal backwards on a bike while coasting forward. Since there are two different sized Wheel Sprockets, pedaling in the forward direction is the higher of the two gears.

When pedaling backwards the chain moves in the opposite direction. The bottom of the Crank Sprocket pulls the chain forward which in-turn pulls on the top of the Small Wheel Sprocket. This also turns the rear wheel in the forward direction. The portion of the chain that wraps around the Large Wheel Sprocket is now traveling in the backward (CCW) direction, and again doesn’t cause a problem because it is freewheel.


Why did [punamenon2] decide to do this? Just for fun! And that is a good enough reason in our book.

[via reddit]

48 thoughts on “Bike Pedals In Both Directions, Gets You To Your Destination AND Back

  1. Ingenious, but when I reverse direction on the pedals, I am acting from the memory that says reversing will brake. And if the reverse pedaling is effortless, my next action is to use the handbrakes. In other words, if I reverse direction, I am expecting to stop, NOT continue forward direction under power!

      1. I understand that is a US typical thing, because in the US they have laws that say you have to have 2 brakes, so they put double handbrakes on them as the most cost effective way, whereas in the rest of the world there are billions upon billion of backpedal brakes.
        At least that is what I heard as explanation, but I know for a fact that there are an awful lot of backpedal brake bikes being made and sold every day.

        1. That is entirely incorrect. Surely there are some local laws, there are fifty states and all, but the reason why most bikes come with two brakes is because that is what people buy. Backpedal brakes are still immensely popular in the US, but only on bikes with only one gear.

          Essentially this is the same as usual, the ignorance of people on the US is at the same level as the ignorance of americans about other countries.

          1. Two independant brakes are law in UK at least. On my wife’s tricycle that means a hub brake and a rim brake on the front wheel. A bit crazy perhaps but ultimately safer. It seems that putting brakes on the two rear wheels of a tricycle is a non-trivial problem.

            Have to say also that the backwards/forwards pedalling bike is a true masterpiece.

        2. Mind you, for someone who grew up learning to ride a bike with handbrakes I absolutely detest reverse pedal brakes. AFAIC, its despicability is right up there with cars with automatic transmissions. (c:

          1. The idea with reverse pedal breaking is that since you pedal forward to speed up, a very natural reaction when trying to slow down is to pedal backwards. This is why many people will recommend reverse breaking bikes to children.

        3. Some local couriers in the city also use backpedal brakes to help reduce weight and increase maneuverability. The bikes are devoid of anything but the bare minimum. If they could get rid of the seat, they would.

          City ordinance requires two brakes which is absurd as very few childrens bikes use handle brakes and young children don’t have the coordination anyways.

  2. Good build! These are prized by collectors – there’s a guy who rides RAGBRAI in full French cycling costume (complete with a garland of garlic) on one that’s nearing 100 years old.

  3. I like the build, but the description of how it works is backwards from the pictures. The chain coming from the front sprocket (top) goes to the small back sprocket (top), so peddling forwards gives drive to the smaller sprocket, but still high gear. The drawings are labeled correctly though.

    One other great thing about this build is the instantaneous gear change by changing direction.

    My only question is what happens if you stop peddling? I assume you still get the coast feature, but haven’t thought that far through the geometry.

    1. Hey, let me make a video to show you something, and then move it around every half second so you can’t see it. And just in case I am still enough for you to see it for a second, I am going to shoot the video with the light BEHIND it, so it is just a black blob.


    1. “That tensioner is actually called a derailleur. It’s only chain tensioning if it was a single sprocket bike.”

      No, a derailleur would move the chain from one sprocket to the other. In this case the chain is permanently passing over both sprockets, and the tensioner simply holds one end of the chain loop in place so that there is a good “wrap” around both sprockets.

  4. I haven’t ridden a coaster-brake in 30-40 years. I see two handbrakes on most bikes I see in world media. There is much ill-ergonomics in the coaster-brake. Having only two short areas of actuation and having to stop pedaling and reverse in a flash. The safety of braking with the rear wheel on gravel is known , but the rest of rear only braking sucks. It’s so much easier to mount a bike with a handbrake, specially if a beginner.
    Two gears with no shifter is far better than one gear and one brake at your feet.

  5. I’m 99% used to handbrakes but reverse brakes still brake when wheel is in water, mud or sand!
    And a child don’t need to wait for a real hand grip to be able to stop all this cinetic energy.
    Reverse pedaling seems fun but I’d like to read more about measured benefits.

  6. I can see chain damage very fast.

    Iv seen allready bike with “reverse pedaling”, but it had 2 chains – one at right and one at left side, worked without any complex setups and gears at both sides :)

    1. probably not: a normal derailleur (tr: derailer) needs a chain that is quite flexible in the axial direction, this one only bend the width of two sprockets. Sure it will wear out, but any bicyclechain does that.

  7. I feel like I would find a way to hurt myself on that thing, but I do love it. I may have been stated already, but in the U.S. our “secondary” brake on pedal brake bikes is to shove your shoe in between the forks and the front tire ;)

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