I often get asked why I use mountain bike SPD’s on my road bike, at races it must seem pretty unusual, everyone knows that road SPD-SL pedal, cleat and shoe systems are faster right? Right! I’m sure they are when measured in a laboratory or when firmly attached to a professional cyclist. But alas I am not a professional cyclist and nor do make a habit of hanging about labs. The reason I use them is because they’re far better for walking on. The cleats are embedded up into the sole of the shoe and made of metal, this means that not only when you walk that you’re not clomping along on your cleats, but even on the odd occasion they do come in contact with the ground they don’t wear away so quickly.
Mountain bike shoes also have more tread on the bottom, this is how they manage to set the cleats higher into the shoe, it has the advantage of being less slippery and a little quieter when walking. No doubt they weigh more than the road versions but I’m sure, at my level of cycling at least, the difference would be negligible and although I hear that you get better power transmission again I don’t think that really matters until you start counting seconds and milliseconds over the course of several miles of riding.
If I had a road bike that I only ever used for races and recreation then I would probably get an SPD-SL road set up but for commuting to work and over to friends houses it’s far more convenient that I can walk short distances comfortably and without smearing my cleats into a fine mist on the pavement. It also enables me to use one pair of cycling shoes for both touring and at home and seeing as I only needed one pair I was able to spend a little more on them rather than stretching my budget between two different standards.