tip if you have an older park DAG 1
 

http://img.photobucket.com/albums/v1...s/DSCF2291.jpgif you have a older park derailleur alignment tool you will find that the alignment boss is quite large. the large boss interferes with the smaller hangers on many new road bikes. a quick fix is to grab a axle washer and slip it on over the stud. this will reduce the diameter of the boss and give you some room to work with. for example trek madone hangers and the DAG 1 dont play well but slip on the washer and its good to go. the pic above is for illustration. the washer i have is larger than normal and the tool is the newer DAG 2

thanks for the tip.

wait a sec, you're using a derailler hanger alignment tool (e.g. bending tool) on a replaceable hanger attached to a carbon frame? And, aren't these hangers alloy anyway?

yes and yes. what's the problem? hangers need alignment even when new

replaceable hangers are replaceable because when they get damaged, they get replaced without impacting the frame. Also, hangers are usually made of non-steel alloys or titanium. These materials are not conducive to bending like steel is. This applies to all non-steel bikes, but especially a carbon one. However, it is possible to bend a allow hanger on a non-steel bike. I just wouldn't recommend it. A new hanger is rarely over $5 retail. What do your Trek tech notes say for this particular Madone?

If you have a brand new hanger that is misaligned, it is either not the proper hanger for the bike or is defective.

Wrong!

Replaceable hangers are not precision made pieces of equipment and should be aligned after installation. The hanger is designed to bend before the frame does whether the frame is steel, carbon, unobtanium, etc. So the hanger is able to be aligned without destroying the frame.

-j

You have clearly never worked in a high volume, high end road bike shop.

Hangers are routinely out of alignment, to preserve the frame. Typical AL hangers can be repeatedly realigned many times before they need to be replaced.