Pedals seem simple enough, but they can be deceptive! There are two sides of your bike: drive side and non-drive side.
The drive side has the chain and the rear derailleur, it’s the right-hand side of the bike when you’re sitting on it. The non-drive side is the left-hand side of the bike.
It’s important to remember that pedal threads are different from the left and right side. They should be marked with an ‘L’ or ‘R’ for left and right somewhere on the pedal or its axle. Plus, bikes from the factory often have ‘L’ and ‘R’ stickers for guidance.
The right-hand side is fairly straight forward, (also known as the drive-side) heavily grease the pedal threads and screw them in (by hand), clockwise.
If the thread doesn’t go in by hand, something is wrong. You’ll only need to do it once, so go slow and make sure it’s square, straight and going in correctly.
The left-hand side (also known as the non-drive side) is where you may have trouble. It is a reverse thread. Again, start with some grease on the threads and screw them in by hand, going in the opposite direction, anti-clockwise.
For the last little bit of tightening its worth using a pedal spanner, to make sure the pedal is screwed in all the way. Pedal spanners are typically used for removing pedals but they can also be used for tightening should you need to.
Worth nothing for you warranty
If you cross-thread or incorrectly install your pedals, it’s often not covered by your warranty. So it’s really important to make sure they’re 100% right to avoid damaging your pedals or cranks. If you’re at all unsure, just pop into your local store and they’ll be happy to help.