how do i reset the front gear changer on my bike?

Question

the large gears at front of bike are shimano gears thank you
rocky.

Answer 1

Don't mess with your limit screws until you're sure you need to! Unless someone's changed them already, they were probably set right to begin with. More than likely what you need to do is get the cable tension correct.

First, take a look at the cable housing and shifter and make sure those are in good shape and seated snugly in the holders. Next, look at the derailleur to see if it's sitting parallel to the chainrings....not twisted. The outer cage should sit just a few mm's above the teeth of the outer chain ring.

Next, click your shifter to drop the derailleur down to the small chainring...this relaxes the springs and pulls all the cable from the shifter. Loosen the cable clamp bolt and pull all the slack from the cable. Tighten it up, hold the derailleur by hand, and pull hard a few times on the cable....then loosen the bolt again and pull the slack out.

This should get you pretty well set. When you put pressure on the shifter, the derailleur should start to move pretty quickly. In the small chainring, the cable should be taught (but not super tight). You can fine tune this with the little adjusting barrel at the shifter. Unscrew it to tighten the cable. Screw it in to loosen the cable.

Be sure to clean grime from the derailleur and lube the pivot points so it can work freely. If you have trouble shifting to the small ring, you may need to adjust the low limit screw but make sure the pivots aren't binding up first. Rusty or damaged cables/housing can cause this, too. If you can't shift onto the big ring or it overshifts and throws the chain, adjust the high limit screw. Check out Park Tool's website for good pics and instructions on that.


http://www.parktool.com/repair/readhowto.asp?id=75


Hope this helps some. It's easier than it sounds.

Answer 2

The front derailier, a cage that sits above your front cogs and which the chain feeds through has two screws on it. These are marked + and -. Start with the - screw. Turn this 1/4 turn. Rotate your peddle and then shift down your gear into the lowest sprocket. If this happens smoothly, fine. Otherwise, turn the screw again and repeat until it shifts smoothly (Keep a note of how many quarter turns you have made, so that you always know where you started from.

Now do the same thing fort the large sprocket, by adjusting the + screw.

For a good idea of this:

www.parktools.com

Luck