I've have damaged my outer chain ring pretty badly. The inner ring is still in good condition. You can see the tips of some of the teeth completely chipped off, others have obviously undergone significant wear. What could have caused this type of wear?

I don't know if it's connected, but the front derailleur does not seem to be lined up correctly with the chain ring in that the front of the derailleur is closer to the chain ring than the back. I know how to adjust it vertically, but can't figure out if there is a rotational adjustment, or I have just bent it out of shape.

* bike is only a couple of months old with about 900 miles
* the rear derailleur works fine
* front seems to require quite a bit of pressure to **** to the large ring

any ideas as to
* what can cause a chain ring to be damaged like this?
* how to properly align my derailleur to the chain ring

thanks!

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hmmm...after looking at the SRAM site, it looks like some of the teeth come from the factory without 'tips'...maybe the ring isn't damaged after all?
Question on the derailleur alignment still open though....

this kind of wear is cause by the chain, it too is wear and need replacing, you might want to check your cassette on the rear for wear.from what i see in your photo the derailer is fine . keep the drivetrain clean and oil the chain will cut down on this kind or wear. the chainring teeth do come in different shape to help the chain shift from one to the other.

Your chainring isn't worn at all beyond some normal chain scuffing here and there. What you're looking at is the shifting gate that's cut into chainrings (the glide in xxxxx-glide) to improve shift response. These are only cut into larger chainrings, including the middle of triples to help the chain climb up, or drop off. You don't see them on the smallest ring because the chain lifts vertically off them rather than derailing to the side in a shift.

Teeth near the gate also see some increased wear because they're struck by the plates as the chain shifts on and off the chainring. Teeth elsewhere do better because they're always meshing perfectly with an already engaged chain.

This question is so commonly asked that there should be a sticky showing a blow up of a typical shift gate, with an explanation.

Thanks for the clarification...
What about the alignment of the derailleur? Should the front and back of it be the same distance from the chain ring, or does it look OK?

Ideally the cage should exactly follow the contour of the chainring, but life doesn't work that way.

The chainring's curvature varies with it's size but the FD cage's curvature is fixed. You can raise or lower it to get it as close as practical (1-2mm clearance at the nearest point) but you can't change the angle. Bigger rings will be closer at the back, smaller ones at the top, so if you move the FD make sure that it clears at all points.

It won't make much of a difference with the angle. I'd lower it slightly so the front is closer to the tips of the big-ring. The outer cage only moves the chainring off the big-ring down onto the smaller one. Really simple operation.

More difficult is pushing the chain up from the little to big-ring. As long as you're not having too much trouble with that, I wouldn't worry about it.