“Clipless” pedals are the type where a metal cleat bolted to the bottom of your shoe snaps into the pedal and keeps your foot attached. I’ve tried two new types over the past few months, which puts me in a good position to compare them.
(If you’re looking for intro-level information, see this Beginner’s Guide to Clipless Pedals.)
Shimano SPD-1
These are the pedals I used on my old Fuji bike for 8900 miles. I feel like they’re well-rounded. Pretty common. I think of them as a benchmark—something to compare against. Clipping in isn’t too hard. They’re double-sided. Kinda heavy. Small amount of float. I rarely accidentally unclip. The cleats are fairly shallow and can be recessed in a shoe with tread.
In short: Average. Decent for commuting. Decent for mountain biking. Low-end for serious road riding.
Shimano SPD-SL
Very common pedal style for road bikes. I think Shimano’s SPD-SL cleats are a copy of Look pedals. The cleat has a horn on the front that hooks under the hole on the front of the pedal (the right side, in this picture), then you push your heel down to lock it in place. They’re one-sided and the bottom of the pedal is rounded and featureless. Couple this with the featureless sole of a standard road bike shoe and these pedals are much harder to clip into than SPD-1’s. If I step onto the wrong side of the pedal my shoe is likely to slide off wildly. Even if my foot is on the correct side I still tend to fumble around a bit.
They do make a nice, clean, audible *snap* when the heel clips in. And they feel great—a large surface area and virtually no wobble. The tension is adjustable and is currently tighter than my SPD-1’s, so I haven’t accidentally unclipped yet. The float is adjustable by using different cleats. I think the cleats I’m using have 3 degrees of float and I’m happy with that.
In short: Great for long road rides. Below average for commuting because clipping in is harder.
Crank Brothers Eggbeater 3
I bought these for commuting. They’re four sided, so clipping in is fairly easy. The cleats are very shallow and don’t protrude from the soles of my commuter shoes, so they don’t make loud scraping sounds when walking on pavement. The float and tension are weird… I feel like the tension is very loose. It hasn’t been a problem yet, but I think I would prefer if they were more firm. They tend to not make an audible *snap* when clipping in, so it’s harder to tell whether you’re clipped in. I find myself having to pull up on my foot to know for sure.
In short: Average. I like them a little more than my SPD-1’s. Good for commuting. Very good for mountain biking (they handle mud well). Average for road riding.