Location: Longview,washington
Hi there how do i tell if my front deraullieur needs to be replaced on my hybrid it has a ton of play back and forth.
It might just need to be tuned.
Shift your front derailleur into the highest gear. If you have a triple, this is 3. If you have a double, this is 2.
First check the alignment of the cage with the chainring. The cage should be 3mm overtop of the largest chainring for clearance, and should be aligned perfectly horizontal. If it's not, you need to undo the clamp and adjust the positioning of the derailleur.
Once you've checked that, and you're shifted over into the smallest chainring, undo the cable. Check to see if your shifter has a barrel adjuster. If it does, dial it all the way in (screw it in by turning it clockwise). Then go back to the cable line, fix it in place, pull it just snug to remove the basic slack from the cable, and re-tighten the cable down.
From here, begin to spin the crank and dial the barrel adjuster out little by little. Try to shift up one gear. If it doesn't shift, shift back down, and dial the barrel adjuster out some more (screw it out by turning it counterclockwise). Eventually, your shifting should begin and you can fine tune for performance with the barrel adjuster.
If you still have bad shifting, such as it doesn't shift down, your front derailleur might be past its service life and needs replaced entirely. Unfortunately, the springs on these can be very cheap, and don't last long. Once they wear out, the derailleur will stick, and have trouble especially in downshifting. The only fix in this case is to replace the entire unit.
How long have you been using this derailleur?
You can tell if needs to be replaced, based on the wear and tear which is linked with the miles you put on this bike.
Front derailleur can become worn and lose its ability to shift smoothly. If you've tried tuning the derailleur and it still doesn't shift well, then consider getting a new one.
If this isn't the case, shifting into some gears might be a problem. This can be fixed by changing the derailleur. Although it might not be the main reason. Tuning could fix it as well. Lastly, the most obvious is damage to the derailleur. Maybe it's bent or not in the original shape.