Sometimes, by no fault of your own, you crash your beloved bicycle. I mean you totally weren't going way too fast, and you definitely weren't in need of new break pads. Gosh, its so nice to talk to someone who just gets that these things happen at random through no carelessness on the cyclist's behalf. Take for example the tragic event that befell my poor Schwinn. One second it was rolling happily along down the street. The next, it was sailing into some landscaping, making a mockery of the mechanical principles of flight. Once I had politely disengaged myself from the junipers that had stumbled across my trajectory, I hurriedly checked on my bike. I was devastated by the amount of damage. I imagined that the front wheel had been destroyed, but it seemed that the frame actually took the brunt of the force. The local bike shop confirmed my worst fears: my wonderful Schwinn was beyond repair!
Well, at least it was beyond the point of being worth fixing. It was pretty old to begin with, and not exactly what you'd call the ideal bike. Still, it was my first road bike, and I felt attached to it. I was determined to bring it back from the junk pile and ride it again.
Step 1: The Plan
The damage was almost exclusively to the frame of the bicycle. The top tube and down tube were both deeply creased. The front wheel only had a minor ding that I probably could have fixed, but since I had a spare, I decided to devote my attention to the frame. Since it was an old, steel frame I could just cut it in half, bang out the dents, and weld it back together, good as new. Cutting the frame would compromise it's strength, so I would weld a piece of steel tube inside for added rigidity. This fix could work for other metals, like aluminum and alloy, but you would need to be or know a very skilled welder. Steel is often much simpler to work with.
Step 2: Cut It
I cut the frame right on the crease using a hacksaw. This minimizes the amount of material lost, reducing distortion of the original shape.
Step 3: Shape It
Using a hammer and various cone and a really large bolt, I started reshaping the bent frame. I tried to restore it to a as round a cross section as possible.
Step 4: Reinforce It
Next, I reinforced the frame by inserting steel tubes. They were actually an old seat post that I cut in half. The tubes each have a slit cut through their length that allows them to contract a bit as the are squeezed inside the frame.
Step 5: Weld It
Once I got the frame pieces back together the way I wanted them, I welded them together. It helps that I have a friend with a welder. If you don't, this might be a good project to try at a TechShop. Alternatively many mechanics and machine shops will do this for a price, particularly if you're nice to them!
Step 6: Sand It
All that remains from this point are cosmetic touch-ups. I sanded the welds to restore frame's smoothness.
Step 7: Clean It
Using a wire brush, I cleaned up the soot and grime to get the frame ready for paint.
Step 8: Paint It
I taped off parts that weren't red before the crash, and used a can of red enamel spray paint to hide the repair. Now all that is left is to put it all back together!
Step 9: Rejoice!
After months in bicycle limbo, my beloved Schwinn is ready for the road! Check out that fresh red paint! Check out the not bent frame! I'm very confident in this repair. In fact, its probably the strongest part of the bike now, since the steel is easily 4 times thicker. There isn't much more weight (about the weight of one seat post), but that doesn't really matter anyhow. I'm not a hardcore cyclist. This bike is for the tour de tacos, not the tour de france. Its just one of my favorite toys and I'm happy to have it back in useable condition! I hope that this Instructable will help you get your favorite bike back on the road too!