I've had a broken water bottle cage on my road bike for a few months. It's carbon, and the little lip on the bottom that holds the bottle vertically in place was fractured. Since the cage was mounted to the seat tube, the bottle bottom would slide past the lip, and rest on the down tube. Although the cage was broken, due to this geometrical "feature" I could still use it, except that the bottle rubbing against the down tube damaged the frame finish and would eventually compromise the carbon frame.
A few weeks ago, I saw a good deal on Bonktown for carbon cages. I ordered them, and when they arrived I grabbed my hex wrenches and started what previous experience had taught me was a 5 minute installation process. When I turned each of the 4 mounting screws, they just turned and turned and turned, with the screw never fully threading out of the boss. That's not supposed to happen. Disgusted, I let the bike sit a few days. The next time I felt like working on it, I cut the carbon cages away from the mounting screws. The bosses had corroded to pieces. The bosses on the seat tube completely came apart, sort of like pulling a wall anchor out of drywall. The bosses on the down tube were in better shape, but were still corroded and malfunctioning. The damage was caused by corrosion from sweat and electrolyte drinks. Without an easy solution, I let the bike sit a few more days to stew in its disrepair.
Eventually I e-mailed a fellow cyclist and wrencher, explaining that the bosses did not appear to be laid up in the carbon itself, but were some sort of compression nut. He gave me his opinion on the options: replace the faulty bosses with poly nuts (rivet-style compression fitting), install studs by fishing screws down the inside of the frame, forgo bottles and use a Camelbak, or buy a totally new frame. The poly nut solution cost $100 for the tool and nuts. The stud solution cost $5 for the hardware, an infinite cost in the headache of installation, and the unacceptable cost of a make-do retrofit. The new frame would cost thousands, including the divorce settlement. I ordered the poly nut kit.
A week later, the kit arrived. I tested the poly nut installation on a piece of plastic that was similar thickness to my frame. It worked as advertised, and was easy to use, so I jumped off the cliff and installed a nut in the seat tube. It held. Frame was not damaged. All was good. I installed the second nut on the seat tube, with the same result. Unfortunately, I still had to extricate the partially broken down tube bosses. I couldn't grab enough screw to use bolt cutters, and I didn't have enough clearance to use a hack saw. My old Dremel tool's rechargeable batteries were shot, so I went to Home Depot and gave them $70 for a new Dremel tool. I used an abrasive disk with the Dremel to grind the screw heads off, drilled out the remnants of the bosses, and installed the last two poly nuts in the down tube.
Now it was time to actually install the cages. When I positioned the cage on the seat tube, it interfered with the front derailleur hanger. At this point, I realized how completely sick and tired I was of working on what should have been a simple project. I drove to the LBS to buy different cages. I had never been to this particular shop in Missouri City, and I felt a little out of place in this boutique shop that only sold Specialized. And just when it's darkest, the light shines. Or something like that.
One of the shop hands saw me looking at cages, and I told him what I was facing. Without trying to up sell me different carbon cages, which is what was tempting me, he told me "come here...let me show you a trick". He took me to the bikes, pointed at the knurled nut that is on a threaded Presta valve stem on a road tube, and said that this innocuous stainless steel nut, which most roadies throw away, works great as a spacer. I left without spending a nickel.
After I got home, I realized I needed four of the nuts. I didn't have four, so I went back to the shop and bought four tubes. I robbed the nuts, used them as spacers, and finally installed the cages. $100 for the poly nut tool, $70 for a new Dremel, $16 for tubes, and probably 5 hours of my own time in my garage.
Why are the easy projects always the hardest and costliest?