Sidi MTB Spikes aren't for your typical trail ride. What they are for are the days that you'll experience sloppy hike-a-bike sections in a race or when you toe the line for a muddy 'cross race. They're easy enough to thread into the toes of your shoes for these days that you'll need extra traction. This set of toe spikes are narrow and sharp and dig in easily. They come in a set of four, two for the left shoe, two for the right.