Introduction: Adaptive Bicycle for Child With Achondroplasia
Jed is a spunky and fearless 8-year-old boy with achondroplasia, a form of dwarfism. He wanted to ride bicycles with big sister and his family, but he didn't have a bike that fit him. Most bicycles that are on the market are too large or have the wrong proportions for Jed, as his limbs are a bit shorter. This Instructable shows how we modified a bike to fit his needs.
Supplies
Materials:
-1 in. x 36 in. 16-Gauge Thick Round Tube
-36 in. x 3/4 in. x 1/16 in. Plain Steel Round Tube
-PRO 2 in. Trylon Short Cut Angled Sash Paint Brush
-Sand Paper (Various Grits)
-Rust Oleum White Primer
-Rust Oleum Gold Rush Metallic Spray Paint
-Rust Oleum Clear Coat Spray Paint
-Pedals
-Tires
-Inner Tubes
-1/8" Sheet Metal
-Bell
-Training Wheels
-Vinyl Stickers
Tools:
-Paint Booth
-Chop Saw
-Angle Grinder
-Mig Welder
-Allen Keys
-Screw Driver
-Torque Wrench
-Sockets
-Vice
-Chain Breaker
-Vinyl Sticker Printer
Step 1: Meeting the Customer
We met with Jed and his mother to discuss their goals for this project, including: wheel size, ergonomically correct posture when riding, ease of getting on and off the bike, and how to make it adjustable as he grows.
Mom gave us specific measurements of Jed's arms, legs, torso, etc., so that we could size the bicycle properly.
We were able to talk to Jed about some of his interests, and he told us that gold is his favorite color, so we planned on painting the frame gold.
They also allowed us to borrow his big sister’s (she also has achondroplasia) custom bike made by Nathan Hooper from ME Hoop's Custom Creations to see what modifications were made on hers. We also looked at some bicycles on Isla Bikes which makes bicycle for people with dwarfism to get some inspiration.
Step 2: Concept Design
We determined that the bicycle we made for Jed would need to have a frame lower to the ground so that his seat could be lower and his feet would reach the pedals. His handlebars would also need to be brought closer to his body.
The following describes the design features and modifications that we determined we would need:
- Raising the handlebars and bringing them closer to the seat
- Removing the top bar from the frame so getting on and off the bike is easier
- Repainting the bicycle
- General cleaning and maintenance on the bicycle
Step 3: Prepare the Bicycle for Modifications
To make the required changes, we started by disassembling the bicycle. By removing all the components, we were able to get a better picture of what we would be able to modify and how we could achieve our design goals. Disassembling the bicycle also helped to prepare the frame for the modifications.
Our project involved changing the structure of the bike frame and repainting it, so after disassembly we removed the paint and primer from the bicycle, which provided us with a cleaner base to prime and paint. The paint stripper we selected was Rust-Oleum™ Aircraft Remover. This was selected because it was able to remove both the paint and the primer efficiently.
Removing the finishes from the frame also gave us more flexibility with how we cut the top frame off the bike. We had access to reciprocating saws, angle grinders, oxy-acetylene torches, and plasma cutters. While a reciprocating saw would have no issue cutting through painted metals, oxy-acetylene torches and plasma cutters require a bare-metal surface because the high heat can create toxic fumes.
Step 4: Step 4: Modified Bicycle
To accommodate for Jed getting on and off the bicycle, the top member of the bike frame was removed.
We used an angle grinder fitted with a cutting wheel as this was the fastest and easiest way to remove it. We then went through with a smaller angle grinder with a cutting blade to get the cuts closer to the frame.
After this, we attached a grinding wheel to the angle grinder to clean up the cuts. Finally, we used hand files to make sure there were no sharp edges or burrs left on the frame that could be harmful.
After the frame modifications were finished, we sanded down the frame with 320 and 600 grit sandpaper to prepare it for primer.
Step 5: Paint
We prepared the frame by using painters tape around all of the holes to protect the threads. We applied two layers of primer using white Rust-Oleum spray paint primer to the bike frame. We sanded the front fork with 600 grit sandpaper as it had already been painted white initially.
After the primer was dried on the bicycle frame, we did two coats of Rust-Oleum metallic gold paint (in between we sanded down the imperfections with 1000 grit sandpaper). Then we did two coats of black spray paint on the front fork.
When the final gold coat of paint on the frame dried, the last thing applied was two coats of clear coat. After everything was dried the bike was ready for final assembly.
Step 6: Final Assembly
The bike was now ready to be put back together. Since this was a bicycle we found used, we wanted to replace as many components as we could with new parts. We installed new pedals, tires, a bell, and training wheels on the bicycle.
The final assembly was basically the same as disassembly but in reverse. We started by reinstalling the pedal crank and pedals, then we installed the front and rear tires. Next, we reinstalled the chain of the bicycle. Finally, we added in the handlebars. The following goes into more detail of the process:
We replaced the tires to get rid of the branding. We used a flat head screwdriver in order to remove the tires from the wheel frame. We added in the new inner tubes and placed the new tires back on using a similar method with the flat head screwdriver. Then we inflated both tires.
Once we installed the tires, we added on the training wheels. The wheels we had purchased were designed so that they can be moved out of the way if needed. This allows Jed to practice riding the bike on two wheels without having to remove the training wheels every time.
Our handlebars were the most complicated part of the process. Jed needed handlebars that would be higher up, and closer to his body. The handlebars that came with the bike had a good grip distance for him, so we decided to replace the handlebar stem while keeping the original handlebars.
We purchased an adjustable handlebar stem from Amazon, but we discovered that our handlebars were a slight eclipse shape, while the stem was designed for circular handlebars. After talking to Nathan from the innovation hub, he advised us to use 1/8" sheet metal to form a collar around our handlebars so that they would fit into the stem. We used the chop saw to cut two small rectangular pieces, then we used the clamps from the stem and tightened the clamps onto the collar using the vice so that they would bend into shape. We removed the handbrake as it did not fit for Jed, and kept the foot break in place to stop the bike.
Once the bicycle was fully assembled it was time to get creative! We used the vinyl cutter to cut out some stickers that said "Jed". We placed the stickers on the bar going across the frame.
The bicycle was now ready for delivery!
Step 7: Delivery!
Once the bike was complete, Jed and his family came to campus to try it out. We had to do a few last-minute modifications, like tightening the handlebars and adjusting the training wheels.
He loved it, and was very excited to ride around on it. He even rode it out to their car as they left!
