If I wanted a smaller ring up front can I use this? I have either Ultegra or Dura Ace setup.

-You have a wide enough bottom bracket to allow another ring in. Also, the small ring must not only fit in, but also 'far'enough from the frame so your front der can shift the chain onto it.
-You have a triple-specific FD to shift ok on all the rings
-You have a RD that will pick up the slack in the chain (make sure that the RD doesn't bottom out and chain doesn't hang loose on any gear combination you want to use. Also the largest chainring/largest sprocket combo must not "stretch out " the RD at it's max)
- You have some kind of spacers to put between your ring and the small chainring, to set them apart the right distance for the chain to be shifted properly
- Your adapter ring has a road-specific bolt circle diameter that matches onto your current cranks (should be 130 BCD)
- you find a small chainring with the same bolt circle diameter as the small bolt circle on your adapter ring.
-you find a set of chainring bolts to hold your small ring/spacers/adapter ring (a normal set of chainring bolts should do the trick)

good luck
brblue

Older octalink or square taper cranks can be adapted with these chainrings, but it requires a longer triple crank BB. Newer outboard cranks can't be adapted.

You will also need a triple FD, shifters that can operate a triple FD and a longer cage RD.

I've always assumed that chainring spacers came with the ring, to properly space the 74mm BCD little ring.

If you try this, get a 39T middle ring, not a 42.

add a 30 t ring onto this 42 t middle ring. The Ultegra shifter I know will shift a triple but I don't know about the Dura Ace. The front derailler is DA, it will likely handle the triple, but I do have an XTR FD that will handle the triple but I'm not so sure it will handle the 30/54
The rear is ok because I will use an XTR long cage and I might be putting on a 12-30 or 12-34 cassette.
This setup is for the Mt Washington hillclimb. 7.6 miles, 4700 feet plus in elev.
It is all uphill so I could take off the large ring to better use the 30/42 ( I probably won't use the middle ring.)
I might end up using my MTB, a Giant XTC carbon frame with some thin slicks and drop bars.

Since you already have the long cage rear that will allow you to use up to a 34 tooth cog, your simplest bet would be to get a compact crank with a 34/50 set up. That way, you won't have to worry about the front derailluer, whether the front shifters will work or even the bottom bracket spindle length. The 30frt/ 34 rear should be an awfully low gear, any lower and you will be at walking speed anyway.

Since you already have the long cage rear that will allow you to use up to a 34 tooth cog, your simplest bet would be to get a compact crank with a 34/50 set up. That way, you won't have to worry about the front derailluer, whether the front shifters will work or even the bottom bracket spindle length. The 30frt/ 34 rear should be an awfully low gear, any lower and you will be at walking speed anyway.

One option is to put a XTR crank on from another bike and the rear XTR deralleur and 34 T cog. I can likely use just the small and middle ring.

This is a very hard climb and a lot of riders use just a single front small ring with a 27 to 34 T cog at back.

One option is to put a XTR crank on from another bike and the rear XTR deralleur and 34 T cog. I can likely use just the small and middle ring.

This is a very hard climb and a lot of riders use just a single front small ring with a 27 to 34 T cog at back.

..also mind that you'll want to have the longest crank arm available since it will be a mashing fest. So unless your road cranks have longer crank arm, just go with the MTB ones. It's the most comfortable solution.

good luck
brblue

http://forums.roadbikereview.com/showthread.php?t=14746&highlight=mount+washington+hillclimb