Road Cycling - Very simple Pedal question...

I've got a mt. bike (which I use mainly on the road) and will be getting a road bike soon. I'd like to get some clipless pedals now and transition them to the road bike once I get one.

Are all pedals pretty much universal when it comes to how they connect to the crank? I know that they are radically different when it comes to fit, function, etc.

You can use the clipless pedals you have now. I had MT. bike pedals on my road bike for a while until i got different ones. They may be a bit heavier than road ones but they should work just fine.

As far as I know, all Mt. bike and road bike cranks have the same thread pattern (spacing), BMX pedals are different (if I remember correctly)
so to answer your question, you should be able to enter change peadls between thoughs two bikes

Most pedals are stamped R and L, the threads are R handed on the R and L handed on the L. With the dominance of the Japanese and E Asian manufacturers, the French threading is almost never seen in modern bikes so the threading can be regarded as universal regardless of source of clipless pedals. If the pedals are not marked, you can get any standard bolt and put it beside the pedal thread and easily distinguish R hand thread from L hand thread. Crank Brother pedals are developing a good rep and usable in walking friendly shoes or road shoes. Steve

To echo the other responses here, you sure can!

I did essentially the same thing. I started with some Crank Bros Egg Beaters on my mountain bike. Switched them to the road bike when I bought it, and used some platforms on the mountain bike for a while. Got fed up with them, so have just bought a set of Candy SLs for the mountain bike. Egg Beaters have been great on the road bike - I have the stainless steel versions which are reasonably light weight. A friend of mine has used Shimano M515s on his road bike for the last year or so, and is very satisfied with them.

If you get some stiff sole mountain bike shoes, you can use the standard egg beater cleats and have arguably as good a setup as with a true road shoe. Or buy a road shoe, and spend another $20-25 on the EB road cleats. They are much easier to walk in than most road cleats, and the release on mountain pedals is usually much easier than road pedals (good for riding around town when you need to click out frequently).

You can pick up Egg Beater S pedals off ebay at the moment for around $65-80 (retail $140).

Basically you only have to worry about one thing: spindle size. It'll either be 1/2 inch or 9/16ths. As far as I know, only one piece BMX-style cranks use 1/2 inch, so you're pretty much guarenteed to be OK.