Have you found a bike with a set of brifters that just don’t shift like they once did? We have come across countless sets of shifters and brifters (also called trigger shifters, Shimano Rapidfire shifters and Shimano STI shifters) that get stuck and cannot reach the full range of gears at the shop.
We at SVBE have used many sprays of WD-40 and Kroil in an attempt to restore shifters like these back to their original glory. Always a messy affair, this method has only resulted in mixed results. I personally have tried this on at least two sets of brifters and all I got was a few new stains with the brifters still not operating fully.
What typically happens is that grease that lubricates the gears, pawls and springs hardens over time, gumming up the shifter's ability to release and engage in all gears.
This sticky problem showed up again for me recently, when the brifters on a homework bike couldn’t make it to the third gear. Our general manager Andrew told me about an alternative method that has been whirling around BikeX. Rather than using stringent lubricants (or just throwing away the shifters in frustration), a simple and effective solution is near-boiling water. Much less messy without the smells and stains? Skeptical, but hopeful, I decided to give this a chance. I put the brifters into a bucket in my sink, filled up my water boiler, and waited for the water to come to a boiler.
Once the pot clicked with the steam rising up, I dumped about 1 liter of water on top of the brifter. There wasn’t enough water to submerge the brifter so I filled up the water boiler with another half-liter and brought it to a boil. After the second round of water came to a boil, I poured this on the brifter and submerged it. After a few minutes (when my excitement could no longer be contained), I poured out the water and gave the brifter a few shifts. The third gear easily clicked past gear two and shifted into third. After a little spray of a Triflow, WD40 or light oil, the brifter is ready for a new life of many miles of shifting.
Andrew often uses this technique while the shifter is still on the bike. He pours hot water using a coffee pot (a narrow spout helps) into all the openings of the shifter. The cable port on trigger shifters is often the perfect place to flood the shifter with hot water. Another upside to hot water instead of harsh chemicals, beyond the environmental impact, is the hot water is gentler on grips, handlebar tape, tires and your bike's finish.
So next time you find yourself with a shifter that just will not budge, try some hot water to release the gears inside rather than making a mess with Kroil or ditching the shifters completely. Happy Wrenching!
Thanks to Christian at Menlo Velo Bicycles, the original source for this tip.