Pros of clipless pedals
We will dispel a myth first, clipless pedals are not there to allow you to pull up on your pedals, this isn’t good technique. What they do allow is for you to more easily scrape through the bottom of the pedal stroke and push over the top of it, which does even out power delivery and improve efficiency. However, these improvements are not as significant as some clipless pedal users claim.
Power transfer and comfort
Clipless pedal shoes will tend to be stiffer, this improves power transfer. It also means less flexing of your foot which, for rides involving sustained pedalling, will improve foot comfort.
No shifting feet
With your feet attached to the pedals, no matter how rough the terrain, they are staying put.
Easy hopping and lifting
Clipless pedals make small jumps and hops very easy but relying on them for techniques such as bunny hops encourages poor technique.
Cons of clipless pedals
Slow motion falls
Almost a clipless pedal rite of passage is the comedy slow motion fall. It normally happens at the end of the ride when you are tired and in front of a car park full of witnesses. You come to a halt, forget or are unable to unclip and over you go.
If you have to stop on a steep climb, getting going again with clipless pedals can be a nightmare.
Clogging up (on snowy climbs)
Most clipless pedal systems have some sort of mud clearing mechanism when you clip in and clip out. However, in extreme conditions, especially ice and snow, they can become frustratingly clogged.
Which pedal system you choose largely comes down to personal preference. Some riders do like to switch between the two depending on the type of riding and trails their doing. For more cross-country style riding, they might opt for clipless but will choose flats for more technical trails or if learning new techniques.