Have Your Bike Dialed
The fit, from frame to stem to pedals to bars to brake levers, is critical in your ability to go fast. If you're not comfortable on your bike you won't be able to go fast. Get the fit dialed then make sure your brakes and shifting are spot on. If you don't have confidence in your equipment, you can't go fast. Experiment with settings like tire pressure and if you have suspension get it dialed as well. Once your bike is dialed and race tuned, keep it that way even if you don't race. A clean, well lubricated and adjusted bike is a happy and fast bike.
Practice, Practice, Practice. . .
Seriously. You must be able to know how your bike will respond in EVERY situation. If you are even a bit unsure, you will not be able to go fast.
Get fit. You can't go fast downhill unless you can go fast. Gravity is your friend but it doesn't do all the work. A big chainring will only give you more top end if you can push it.
Read the Trail and Pick your Line
In general, look as far down the trail as possible. The faster you go the further ahead you need to be looking. In general, you and your bike will tend to go where you are looking. If you are looking right at that big rut down the middle of the trail, it will most likely make a meal out of your front wheel. Identify possible hazards in your path as soon as possible, then don't focus on them. Instead, focus on the best path around, over or through them and focus on that line as you continue to scan the trail ahead. In a real scary section, look where you want to go, not at big rocks and ruts. NEVER look down at, or just in front of your front wheel at speed unless it's for just a split second. Keep your head up and eyes down the trail. It's okay to let your eyes flit up and down the trail, but concentrate on looking ahead as much as possible.
Hop Your Bike
I hate the term bunnyhop, but I love to practice the technique. It is a must do to being able to go fast. Most of the time you don't need much height. This is especially true at speed. Learn to time your hops so that you spend the least amount of time with your wheels off the ground. Learn to do it several times in rapid succession. Learn to do it and be able to change direction slightly. This comes in real handy in really rough rocky or rutted sections.
Let the Bike Work for You
Try to think of your tires as edges on a pair of skis. Keep your weight centered over your bike and let your bike dance around beneath you. Keep your grip firm on the bars, but your arms and legs lose. Keep your but just off the saddle. Don't put much weight on the saddle and remember keep the weight on the outside pedal. I like to have the outside pedal slightly towards the rear of the bike and put as much weight on it as possible. The inside foot is either resting lightly in the clips with the knee pointed away from the bike or I pull my inside foot out and stick it up near the front wheel and out slightly. It depends on the speed and terrain. If you don't have suspension don't worry about the wheels wanting to bounce around. Let them. Just keep your weight centered, look where you want to go and keep the bars pointed in that general direction.
Know When to Go Slow
This is one of the most often overlooked parts of going really fast. Knowing when to slow down, and more importantly, how much to slow is critical to blazing fast times. The brakes are your friend. Use them wisely. Remember, about 70+% of your braking ability comes from your front wheel. When you really need to scrub speed quickly, grab a healthy handful of front brake. Never lock up the front wheel and do not try to scrub speed once you have committed to a line through a corner. That would be a really bad move. If you come in to a corner too hot and you need to scrub speed, use both brakes and use them sparingly. Or, better, just lean more sharply. It's best to enter the corner at the fastest speed that you can safely carry through the corner. Practice braking later and later for the turn. Many times the person that brakes later, and correctly, will be the first one out of the turn and on the pedals sooner.
Wear the Gear
Wear your helmet, glasses, gloves, cycling shoes and shorts. There is nothing worse than having a bug or small bit of debris fly into your eye at speed, or to have a bush or tree branch reach out and whack you upside your unprotected head. If you fall without gloves and helmet I guarantee it will be painful and ugly.
No Fear. . .
This is what really separates the posers from the people that go fast. If you have confidence in your equipment and your abilities, then you are well on your way to increased speed. Confidence = trust = no fear.
I have found that a big ear-to-ear grin and rebel yell will definitely make me go faster. Try it. Don't be so serious. There is nothing like being in really good physical shape and being really in tune with your bike and the trail. Good luck!
By Chris Barrett.