When a 3d printer saves you 2.44€

Today on my bike commute home, I switched gear and noticed something coming loose in the break/shifter handle. I immediately stopped but only found a tiny piece of broken off plastic. After this incident I was unable to switch the front derailleur anymore. When I came home I first tried to figure out where the broken off piece was coming from but I could not find anyplace that made sense. I did find a lot of grime and managed to clean it off with a lot of WD40.

After this frustrating find, I had to go digg deeper. For this I had to remove the rubber hood (roll back and pull hard over the lever). I then tried to see what was (or not) happening. It seemed that the rachet mechanism wasn't engaging the ring that pulls on the derailleur correctly, or rather the tooth that was supposed to hold the ring was in the way and didn't let the ring slip past. In any case it seemed like things were broken. It also noticed that the whole ratchet was moving around. I managed to fix this by removing the whole lever from the handlebar and tightening the anti-fixing snake-eye screw. After consulting with my favorite LLM chatbot, where nothing intelligent came up, I gave up about the mechanism itself. Since a replacement part costs 130€, I already did some research on ebay to find a used lever.

Me being lazy and not wanting to go to the basement anymore to check the exact model, I watched a few videos where the thing is being disassembled. And there I miraculously stumbled upon this video talking about a little wedge piece (called part no3, main lever support, Y63X80000, Y63X80010 or shimano spacer) that needs to be present to allow changing gears. I quickly checked and even if my shifter is a different model than the one from the video, it has the part in the working shifter whereas it being missing in the "broken" one. I had finally found the issue. I already made plans to design a replacement part but thought that there might be one already on thingyverse . Since this is a common issue, there were multiple versions of the part there already. I quickly printed it in left and right version (I had obviously broken the intact one while taking it out from the right shifter) in PETG. After a fiddly insertion procedure, I can now change my gears again and won't have to take public transportation to work tomorrow. What a relief!

PS: If you happen to have the same problem but don't own a 3d printer, you can also order the part from aliexpress .