I bought a Giant TCR Composite road bike yesterday and since it comes without a pedals i bought a MTB clipless pedals but i don't feel comfortable with this pedals, so should i buy a road bike specific pedals and shoes -as it is a clip pedals- or it is just a matter of time then i will be used to it ?
First, note that if you're new to clip/clipless systems, it takes a while to get used to it.
A lot of non-racers prefer mountain bike clipless pedals (e.g. Shimano SPD) since you can clip in on both sides of the pedal and the shoes often allow the cleats to be recessed (so you can walk around). Mountain marketed shoes generally tend to be more comfortable as well. An example SPD pedal is:
Note that some SPD pedals also double as platform pedals, so you can use regular shoes.
Road pedals (e.g. Look/ Shimano SPD-SL) have larger support for the shoe but only allow you to clip in on one side of the pedal. An example of SPD-SL is:
However, at the end of the day, the pedal-shoe combination is completely up to you. You could use road platforms, toe clips, mountain bike clipless, road clipless, etc. - do what makes you most happy.
See this excellent question as well for comparison of pedal-shoe systems.
A lot of causal riders appear to prefer SPD's, which is a great place to start, but I here is the argument for SPD-SL like systems. Which I personally prefer and even on dirty muddy roads.
Road bike specific pedals (e.g., SPD-SL) are designed for a single purpose, road cycling, and the pedals do this job well. Road cycling has a lot of repetitive motions (you often sit in the same position for a long period of time) so fit can be key to reducing repetitive stress injuries. If you get into long rides, high mileage or fast and hard rides you will notice the difference over mountain bike pedals. Because you change your position quite often in mountain biking the small nuance issues of fit in road cycling are often a non-issue in endurance mountain biking.
Pros - Road Pedals (SPD-SL and others)
- Smooth float - Pedal float is the ability to allow the shoe to swivel (and shift laterally in some systems) slightly during the pedal stroke. This can be important to reducing certain types of injury (and optimizing alignment) as your foot can shift slightly in the pedal stroke. Mountain bike pedals use the shoe tread as the contact point, while road pedals use a specialized cleat as the contact point. As such, road specific pedals can choose materials and control the contact patch better allowing a much smoother float (and often more float) than mountain bike systems.
- Note - Some claim that float reduced power, but there is no real evidence for this idea. See the myth section in Phil Burt's Bike Fit.
- Wider Contact Area - Because they do not require the same ability to shed mud and dirt, road pedals have a large interface surface with the cleat.
- Reduced Hot spots - The wide contact area distributes pedal force over a larger proportion of the shoe, which in turn better supports the foot. Assuming your shoe fits properly, this will result in reduced likelihood of hot spots. Hot spots can occur over long periods of riding, where a pressure point exists under a small potion of your foot which causes discomfort.
- Better force transfer - The wider contact area allows for a more efficient transfer of force as there will be less flexing
- Lower Profile - Because the tread block is not required the road shoes can often be placed closer to the pedal axel. This can allow less rocking (more efficient power transfer) and allow for more clearance (aka harder cornering)
- Lower Weight/Lower Rotating mass If you care about such things (many do) the road pedal/shoe combo is typically lighter. This can provide minor performance gains.
- Lousy to walk in
- This can cause accidents - After using road shoes for nearly 20 years I finally had my first accident, which hand me sliding across the kitchen floor (while avoiding small children) and crashing into the stove, where as luck would have it my hand landed on a red hot stove element! I still went for a ride though...
- No hike a bike - Suppose you use up all your tubes (@CareyGregory), your frame is cracked and can't be welded because you are out riding across some African plain and there are no good TIG welders around, you are running out of water and you still have 10 miles to go. Well now add your shoes to your list of problems because you are not walking in them.
- They sound funny - Depending if you look hot or like a stuffed sausage when you stop in for your pre-ride caffeine binge, the ensuing clickety-clack caused by road shoes may cause you horrendous humiliation!