How to Build a Recumbant Bike

Recumbent bicycles offer a more ergonomic seating position than traditional, upright bikes.

Recumbent bicycles are often favored over standard, upright bikes for their enhanced comfort and their lower, aerodynamic profile. Building a recumbent bike from two old ten speed bicycles can be challenging and requires some advanced mechanical skills, such as welding and brazing. However, since a recumbent bicycle can be built for a fraction of the cost of a new bike, assembling one can be a worthwhile experience.

Things You'll Need

• Two old ten-speed bicycles
• Hack saw
• File
• Six feet of 7/8-inch aircraft tubing
• Sandpaper
• Brazing torch
• Brazing material and flux
• Conduit bender
• Recumbent bicycle seat
• Recumbent bicycle handlebars
• A small wheel, such as from a child's bicycle

Instructions

1. Prepare one of the bicycles. Remove the components and keep what you will need for the new bike. Carefully saw off the rear triangle and save it for later. Cut the seat post out, sawing where it meets the bottom bracket, and 9 inches along the top tube (Section A). Clean each cut with a file.

2. Prepare the second old bike. Discard all the components but the chain, then remove the steerer tube, cutting 9 inches along the down tube, and along the top tube where it meets the seat tube (Section B). Cut out the bottom bracket, sawing 12 inches along the seat tube, 1.5 inches along the down tube, and 1.5 inches along the chain stays (Section C). File each of the cuts clean.

3. Begin putting together the new frame. Join the top tube of Section A with the top tube of Section B by inserting one into the other. This joint can be stretched or compressed to adjust the bike's size. Connect the down tube of Section B with the down tube of Section C, then connect the seat tube of Section C with the top tube of Section B.

4. Complete the new frame's assembly. Heat up the seat stays of the previously saved rear triangle, and bend them at the rear dropouts until they are about 9 inches from the chain stays, then attach the seat stays to where the seat and top tubes of Section A meet. Connect the chain stays to the bottom of Section A's seat tube, then connect them to the chain stays from Section C using the aircraft tubing.

5. Weld each of the joints. Clean each joint by sanding the connecting areas, then braze the joints together. Once the connections have cooled, make sure each one is stable.

6. Bend the fork from one of the old ten speeds using a conduit bender. Bend the fork blades enough to allow sufficient maneuverability, taking care to bend each blade the same amount.

7. Attach the components. From one of the old bikes, reuse the fork, stem, headset, brakes, rear derailleur, brake levers, shifter, cables, rear wheel and crank set. You can connect the chains from both bikes together to form one long enough for the new bike. Attach the new seat and handlebars. Use the child's bike wheel as your new front wheel.

References

• Recycled Recumbent
• Recumbent bike plans with drawings