You probably suck at corning. Sorry to be blunt, but even if you already race, I have to tell you, most Cat 3,4,5 cross racers are pretty terrible at cornering. I’ve literally passed half-a-dozen people in a single corner in a CX race. I’m sure they all passed me right back on the next climb on long straight-away, but the point is, they lost a lot of time because they didn’t know how to get through a corner effectively. Multiply that by every corner in the race, and multiply that by every lap. Mountain bike races have a lot more corners than a cross race, and most of them are more technically challenging. Aside from getting fitter and stronger, learning to corner faster and harder is probably the best way you can make up more time in races.
Use the whole trail: Let’s start with the basics. A single track trail might be 8” wide, it might be 2’ wide. There’s no rule you need to ride right down the middle of it. Before we get to cornering proper, you have to think of the trail, not as a single line, but as a broad swath of route options. Imagine a gently bending section of trail. Now imagine yourself riding the straightest line possible through these gentle bends. There are a lot of factors that might effect the fastest line down a particular section of trail, but the straightest line between two points is always the shortest, and its a good place to start. Now, let’s apply this concept to corners proper.
Wide-tight-wide: You want to use the whole corner so you ride the straightest, and therefore fastest line through it. That means starting wide, entering on the outside of the corner, cut tight to the very inside corner, and exit wide to the outside again.
Put your outside foot down: You’ll be leaning towards the inside of the turn so keep that inside foot/pedal up and out of the way. You should actually be pushing down through the outside foot to increase the load on the tires, and thus traction (more on this below).
Loading your tires: Pushing your bike down into the corner will give you more grip in the corners. You’re driving the bike through the trail with your downward thrust. Your outside pedal should be down and you should be pushing down through it. Typically, I load the front tire a little bit more than the rear, pushing through the corner with the front tire. You should be putting force down on the rear tires too, but the difference is that if the front tire slides out, you are going down. If your rear tire slides out, you can usually recover.
PRACTICE!: Feel out how hard you can corner. Get a baseline feel for how hard you can corner at various speeds. Find someplace that’s just packed dirt, maybe a construction site, maybe a firmed-up baseball field, a packed-gravel lot if you have to, whatever. If you can’t find a big area of dirt, lawn will suffice. The dynamics and break-away points will be different than on dirt, but what you’re trying to determine is the feel of your body and the bike before breaking traction. Now, just practice making turns. Go a bit faster and/or tighter each time, lean your bike over harder each time, incrementally, until your tires start to let loose and you skid or go down. You may want to do this without clipping in. A good tire will give you some warning before it lets loose, but its not uncommon for a tire to just let go in the corner unexpectedly. See how you, your bike and your tires handle corners so you have a feel for how hard you can push it on the trail. Now, that you know the limit, keep it going a few more times, keeping yourself just inside the breaking point for traction.
PRACTICE!: You’ve got to be smooth before you can be fast. Start out practicing cornering at a slow speed, a speed at which you can easily handle the speed and can think through what you’re doing as you’re doing it. Get the technique down, get the line down. You should feel smooth and steady. Then once you think you have it, start pushing yourself to go through the corners progressively faster. Good technique is more important than absolute speed at this point.
Now that you have a plan, find yourself a short section of trail with several corners that you can easily repeat and ‘session’ over and over. You’re going to want to ride each corner 5-10 times each in this outing. Now, here is what you’ll be practicing:
Do your breaking before the corner: The contact patch of your tires only have so much grip. That grip can be used for braking or corning, or some combination there of. If you’re using some of that traction for braking, you’re not using all of it for corning as fast as possible. Decelerate to the right speed before you hit the corner. Then hold your conviction, keep your fingers off the brakes, and rail it.
If you must brake mid-corner, use your rear brake only. The rear tire might skid around if you over do it, but this is easier to recover from. In certain conditions a skilled rider can even use a rear wheel skid to adjust their angle on the trail and exit the corner faster.
Look through the corner to the exit: Seeing as far as you can through will help you understand how to set-up for it. Look for the line that will give you the fastest exit. Look for any anomalies that might cause you to alter this line a bit. You can’t always see all-the-way through a corner, but look as far as you can. Keep your eyes on the point you need your bike to go. Push your body and drive your handlebars to get there.
Bermed Corners: Once you learn to handle them, a berm allows you take a corner fast. You can lean into the turn and the centrifugal force you generate becomes downforce pushing your tires into the berm, giving you better traction. So how do you make the most of it? You still want to maintain as much momentum as possible. In this case you’re going to use your momentum to build elevation up the side of the berm, and then set up your exit for the berm so that you turn that elevation back into momentum. The faster you are going the higher you should go up the side, but if you go too high you will bleed off too much speed, and of course, you are riding a longer distance and taking more time covering that distance. You should feel like you’re forcing the bike to stay down a bit more than it naturally wants to. You should reach your highest elevation on the berm at the midpoint of the turn or slightly before you reach the midpoint. Its smoother and easier to have a steady arch through the turn, but squaring the turn a bit earlier gives you a little better control and speed for your exit.
Finding berms on flat corners: Modern trails are built, to shed water off the side rather than letting it run down the length of the trail. As trails are used more, they tend to cut in, developing a shallow rut from erosion and soil compaction. As a result of this design and wear on a trail, trails will often form mini-berms in flat corners. Try to uses these little edges when you can find them to push against, hold more traction and maintain more speed through the corner.
Sometimes a berm is a distraction: Sometimes poorly made berms, are not the best line through a corner. Same goes for those wear-created mini-berms, after all, most people don’t take the best line through the corner. Don’t force yourself to use a berm if it doesn’t seem like the best line.
Pass on the inside on corners. Now that you’re smooth and fast in the corners, use this to your advantage. If you’re looking to pass the rider in front of you, watch for an opportunity when they will hit a corner wide. You will need to anticipate this, accelerate before the corner, set-up wide, come through the corner inside of them, and get by them in time to exit wide.