We're going to talk about adjusting your front and rear derailleur.
If your front and rear derailleur are not working properly, it could be a number of different things. Basically there's a thing right here called the derailleur hanger. If your gears are kind of skipping all over the place, that could be bent. It's made to bend so that your frame doesn't actually crack.
It could be that your chain is worn out. It also could be, we see a lot of times, where the cable in housing hasn't been replaced in a long time. Basically that gets corroded, and it can't move properly in and out of this piece of housing. That could be for both front and rear, the reasoning for why it's not working.
This is a brand new bicycle, so those things won't be an issue, but to adjust the gears you're going to need a Phillips head screwdriver, and this is either a three-way, which has three different sides, or you're just going to use a 5mm Allen.
To start out you want to make sure that your rear derailleur is shifted all the way down to it's smallest gear here and that you take the tension off of the cable. The cable tension is what allows the derailleur to go up and down.
Now we're going to in the back here. This is kind of an advanced thing. You may want help from somebody who has done this a couple different times, because it can be dangerous if it's not done properly. These are called limit screws, and it limits the derailleur from either the chain going into the frame or the chain going into the spokes; which can be very dangerous because it could actually push the derailleur into the spokes and break the spokes while you're riding.
What we're going to do is we get really really close, and look at it completely straight up and down, and see where the derailleur is. There is usually an H and an L, meaning high and low gear, on the two different screws. If not you could just try out a screw and see if it works, and then if it doesn't then unscrew it and try the other one.
This is the high screw, and we're in the high gear which is the the smallest gear here in the back here. It's the hardest gear to peddle. You start screwing that screw, and you'll feel resistance eventually and you'll the actual derailleur move. You can see the derailleur moving back and forth.
What you want to do is you want to get that nice and straight to the actual cogs, so it's nice and straight up and down. You can see if it's going to fall off, if you can just pull the derailleur. I'll show you what I'm talking about here. If it's not adjusted properly, the derailleur will pull right off and go right into the frame. See that, how it's coming off and going into the frame.
Just to tighten it down so it's pushing towards that way and it's not skipping up. If you do it too much, it'll start to skip up into the second gear. You can see that, so that's not good. You want to make sure that it's at the proper location.
Now that's adjusted properly on the highest gear here, which is where you want to start. You're going to place the cable onto the nut here. Basically what you want to do is you want to be finger tight at first, making sure that this barrel adjuster has been zeroed out. Zeroed basically means that it doesn't look like it's very far out like this. You kind of want to make it flush with the plastic and the metal or if it's metal, metal. Whichever it is. Then you have some room to either make the cable a little bit tighter or a little bit looser, just as very small adjustments.