Go to any cycling forum, or any forum on the interwebs really, and you'll find just about any opinion you can imagine. Look hard enough and you'll find the answer you're looking for when researching a new purchase (you already know what frame material and tire you really want before the endless analysis begins, so just go buy it!). Opinions on pedals are no different. The most common types to choose from are clips (the 70s called), clipless (yep, you'll probably fall a few times at first), and flats (I don't want to fall a few times at first).
For pros and amateurs that do more with their bike than ride around the block the following questions have arisen many times. Do you like the pedals you have? Would you like a different brand/system more? What are the pros/cons of each type? Is a pulled pork sandwich the greatest sandwich of all?
In this post I'd like to go over some of the basic advantages and disadvantages of clipless pedals, why they're different from other types, and a few use cases to help you decide if they're right for you. No matter what info you glean from this, I always recommend trying everything when it comes to cycling equipment (and beer).
Flat pedals have their place and have gained in popularity over the last few years, especially with mountain bikes (what's old is new). I personally use them on bikes that I use for casual rides or for more difficult terrain and conditions (snow/ice). There are many styles of flat pedals to choose from. You always can stick with the black plastic pedals with reflectors that many bikes come with. You can also choose to upgrade to the steel or aluminum pedals with set screws on the surface as a type of stud to hold your shoe a bit better. I like to call them shin shredders and have the scars to qualify the name. Studded flat pedals are great on a fat bike for winter riding where you frequently have to put your foot down due to deep snow or slick ice. In this situation, clipless pedals can also freeze and make it difficult to twist your foot out of them.
What is clip style pedal? A clipped pedal uses a strap or 'clip' to keep you attached to the pedal as opposed to a clipless cleat. You might see a clip style pedal on a hipsters bike or that old 10 speed in your parent's basement. I'm not really going to go over clips in this post since they aren't that relevant these days. I believe that bike couriers might still use a clip variant due to frequent stops and sketchy traffic situations often encountered in large cities. In the case of couriers, I've seen a leather or nylon strap fastened diagonally across the pedal to give you a bit more power on the upstroke. I would also imagine walking into a fancy office building with cleats might be frowned upon.
Finally, lets talk about clipless pedals. To get started, you need to buy shoes that are clipless compatible and attach the cleat that usually comes with the new pedals (it usually comes with the screws too). Be sure the shoes are compatible with the brand/system of pedal you purchase. Once you install the pedals and cleats you are good to go (after minor adjustments to cleat position for comfort). Attaching your shoes to the pedals, or 'clipping in' as the cool kids say, as well as unclipping, takes some practice. Eventually, the simple movement will be ingrained in your muscle memory. I'd recommend practicing clipping in and out while someone, or something, holds the bike upright. You could also practice while riding around on a soft surface like grass until you get the hang of it.
I never claim to be an expert on anything, but I have been riding with clipless pedals for a little over 20 years so I've had some time to get used to them and figure out what I like and dislike. I've tried many different pedal brands and systems over the years, but the one brand I always go back to is Shimano and their SPD line of clipless pedals. To me, they represent a no fuss no muss pedal. They aren't anything fancy, but they work, and work well. They may not shed mud as well as an Eggbeater pedal, but I've never had SPD pedals jam up (well, once because of ice about 20 years ago, but that's another story). They may not have as much float as an Eggbeater or Time pedal (float is the movement in the cleat/shoe interface that allows your foot to move around a bit before unclipping completely, many people like it due to knee issues), but they have 4 degrees of float built in and that's always been enough for me personally. The Time and SPD pedals are for the most part bullet proof in my experience and will provide years of trouble free service. I'd still have my original Shimano 747s if I hadn't sold them with my Klein Pulse Comp (oh the regret). I haven't had as much good luck with Eggbeaters and have had a couple of sets give out on me.
If you are set on SPDs due to my eloquent breakdown of all options, then lets break down the trim levels and styles. I typically go with the XT level of pedal. The XT level has all of the bells and whistles of the XTR level, including tension adjustment, but in a slightly heavier, more durable package. Depending on the generation, the XT level may not be as rebuildable as the XTR level pedal either. Shimano also offers a 'Trail' version of the XT and XTR with a cage around the front and rear of the pedal. This feature helps protect the pedal as well as give you a bit of a platform to stand on in case clipping in is a bit difficult at any given moment.
From there you can get a single sided SPD pedal with the opposite side being a flat pedal, such as the PD-M324 or A530. These are great if you want to go for a cruise in sandals one day and hit some single track the next without switching pedals. Shimano offers a fairly extensive line of SPD compatible pedals. You can also buy knockoff brand pedals that will work with SPD compatible shoes, but I can't comment since I haven't tried any of them.
In the past week or so I've decided to give SPD-SL pedals a try on my road bike after experiencing foot discomfort on a multi-day triple century. Supposedly the SL Shimano pedal offers a few advantages to the roadie. Those advantages include lighter weight, a larger platform, stiffer shoe options and a highly adjustable interface between the cleat and pedal. I am hoping it solves the foot muscle discomfort issue I often have on rides of over 50-60 miles. I won't get into all of the particulars with the SL variety of road pedal right now since I have never used them before. However, have no fear, I will report back after a few hundred miles, including a fall count, as I get used to a completely new pedal system. We'll see if it is truly possible to teach an old dog new tricks.
In conclusion, if you are thinking about giving clipless pedals a try, I highly recommend at least trying the SPD variety. It may work for you like it has for me. I know other people who swear by other systems, so your mileage may vary. With many options to choose from and an endless variety of shoe (and even sandal) styles to choose from you will be spoiled with choice and experiencing a more connected feel on your bike rides, whether on road or off. Be sure to have patience and try out whatever pedal system you choose for at least a few dozen miles. For everything but the most casual bike rides, clipless pedals are a great option.
As always, if you have a specific question on this topic that I did not discuss above, please comment below or send me an e-mail and I will do my best to answer your question or find someone who can.