Ask a Mechanic: De-Gunking Your Front Derailleur

Brooke asks “I’ve noticed that most hydration mixes are incredibly sticky and gummy when spilled. After a while my front derailleur is all gunked up. Is there a best practice for cleaning my front derailleur?”

If your front derailleur goes from shifting well to being slow and sluggish, the problem may not be in your adjustment, but may be a problem with your hydration. Almost all hydration mixes, no matter the brand, are incredibly sticky, and tend to spill out over your bike’s down tube and front derailleur. Dried drink mix attracts dirt and grime to your derailleur and bottom bracket area, making for a gunked-up mess.

Poor shifting performance may be traced to the cable, the derailleur itself, or both. As more fluid is spilled, the cable guide on your bottom bracket will accumulate gunk, causing added friction on the cables that will keep them from sliding freely. Being that problems are best dealt with proactively, the best way to prevent this is by cleaning this area of your bike after every ride before the spilled drink can dry.

Inevitably, drink mix fluid will also cake up on your derailleur. Luckily for you, getting the derailleur back to normal operation is a fast and easy process. Grab your favorite bike wash and liberally spray down the front derailleur. Once the derailleur is soaked with cleaner, shift the derailleur a few times to work the cleaner into the pivot points. Wipe off as much of the grit and grime as you can. Once that’s done, be sure to lube the derailleur’s pivot points. Dumonde Tech Liquid Grease works best, but any all-purpose lube will do the trick. After lubing the pivots, you’ll once again want to shift the derailleur a few times to help the lube penetrate into the pivots. Don’t forget to give the cable guide under the bottom bracket a little attention here as well with your cleaner and scrub brush. Wipe away any excess and you should be good to go.

Poor front shifting can ruin your day, whether you are riding for the podium or personal glory. Make sure your drink mix isn’t hindering your performance: maintain your front derailleur before it gets all gunked up.