What's the adapter needed for road?

That means an adapter to fit the 2-bolt SPD Pattern cleats.

If you have shoes with and SPD pattern sole, there's no adapted required to use these pedals with those shoes on any bike, mountain or road.

If you do want to use any Crank Brothers product with a 3-bolt soled shoe, you will need to either buy a 3-hole to 2-hole adapter, or you could simply use a Crank Brothers Quattro cleat.

These are the 3-hole Quattro cleats:
http://crankbrothers.com/3hole_cleat.php?itemId=

These are 3-hole to 2-hole adapters:
http://crankbrothers.com/3hole_adapter.php?itemId=74660

Also, an additional note:

If you are looking at these as a first-time clipless pedal user, I think they might be a good fit. I started using clipless pedals on a set of Eggbeaters, and I found the 4-sided entry a pretty big help to figuring it all out; but I thought that the incredibly small platform made it a bit difficult, especially as I developed as a roadie. Either way, I'm probably going to continue using the eggbeaters on my cyclocross bike in the future.

My point is, if you're new to clipless pedals, I think the 4-sided entry is a plus, and that these have an added benefit over the eggbeaters of a larger platform, which I think will make them easier for beginners to use, and also makes them a very versatile set of pedals that is good for many disciplines.

However, If you're strictly a road cyclist, it may help to begin learning on a set of Keo easy or Keo Classic pedals, and just get used to kicking the pedal over to the entry side from the get-go.

(P.S.: I recommend those two models because they are the two pedals in the LOOK line that have the lowest entry-exit spring tension, which is quite beginner friendly. I personally skipped to the Keo Sprint when I began to use road pedals, and after an adjustment period, am pretty comfortable with them.)
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