- Parent Category: MTB in Hong Kong
- Published on 17 June 2008
- Written by Julien Lallemand
Core Skills: Braking
Riding trails on a mountain bike makes you brake much more than you ever used to in any other type of cycling. You will often have to use the full capacity of your brakes in order to stay on the track. You must explore how quickly your brakes can stop so you’ll know your optimum braking distance for a given speed
Always be ready to brakeYou must ALWAYS ride with at least ONE finger on top of your brake levers. You must be ready to brake anytime.
Adjust your brake levers so your fingers fall on the lever’s tip, and your forearm, wrist and fingers are aligned.
Remember from the Balance section how your center of gravity projects a point on the ground that falls midway between your two tires.
Graphic: The harder your brake or hit something, the more you will be pulled forward by gravity
When hitting the brakes this line attached to your heart is moving forward – like a string with a free weight attached.
If this string ¬points further than the front tire’s contact point with the ground, you’ll be pulled forward and go over the handlebar. Braking hard is like hitting a rock—if your brakes are strong your center of gravity will be thrown forward beyond your ultimate balance point.
Graphic: braking or hitting an object is the same, your center of gravity must remain behind the front wheel's contactop int with the ground
This balance point shift has a dramatic effect on your braking. All your weight gets on the front tire and the rear one is left with almost no traction. You need traction (or grip) to brakes. With weight your tire plants into the ground and stops you. Without it, it just skids.
Brake balanceBalancing your brakes means applying sufficient power to slow down the wheels without stopping them from turning, or causing the bike to skid. Because braking involves a mass transfer from rear to front, you’ll need more power to slow down your front wheel than your rear. The brake balance varies with how hard you are braking and how steep the slope is that you’re going down.
Riding on a flat section of tarmac, the braking balance between front and rear will be about 70% front / 30% back. But as soon as you’re braking harder, the front percentage will increase up to 100% front / 0% rear in extreme cases.
MISCONCEPTION: Some people think the back brake is safer going downhill. This is absolutely wrong. You cannot stop on a steep downhill with your back brake only.
Some extreme situations make braking impossible. If the deceleration is too brutal or if the slope is too steep, the mass transfer will be completely horizontal. No weight will be applied to the front tire and no grip will be available to stop you. You will only slide down. Avoid putting yourself in such a situation in your early mountain biking days! The only way to get out of such a situation is to let the bike go until you hit a spot, giving you enough grip to brake again – these are advanced riding skills.
Braking postureBraking harder than usual is like hitting an obstacle.
Get off the saddle and shift your hips back, get your upper body closer to the bike and allow some flexibility to your arms to absorb the impact.
Going down a step or over any kind of obstacle will require releasing the brakes for a split second – just enough time to get over the obstacle. You do not want to add up the impact of an obstacle with the impact of braking. So if your bike tilts down while rolling down a step, you must release your brakes to avoid your center of gravity being thrown forward and over.
Graphic: braking adds up with impact and slope
Practice: Caution!All the following exercises can be conducted any time during a ride. Start on clean, paved paths and repeat the practice when you can on other terrain. Go from paved ground to hard packed dirt to loose soil, mud and gravel (the most dangerous). Your goal is to brake progressively harder and in the shortest distance possible, without skidding.
Practice: Discovering your brakes.
- Find a flat surface where you can ride for 100 meters at moderate speed.
- Find a mark on the ground that will define your braking point.
- Ride towards it at moderate speed.
- Get in a safe position, off the saddle (very slightly), stable on both feet, horizontal crank (if your crank are not horizontal you will automatically turn while braking).
- Get ready for braking by shifting your upper body backward. Here again shift your hips back first, collapse your upper body and then push slightly back on your bars but DO NOT have your arms fully extended – you’re ready for the braking impact.
- BRAKE ON A STRAIGHT LINE. DO NOT attempt to turn while braking. Use more power on your front than your back brake. DO NOT cling on both brake levers, go progressively, and repeat the drill to increase the braking power.
- Come to a complete stop and notice how far you are from your braking point
- Repeat the exercise until you feel comfortable braking hard and you’re not skidding anymore.
- Then find a gentle slope where you can gather a lot of speed, and try to stop in the shortest distance possible without skidding.
CAUTION: DO NOT HANG from your bar, with your arms completely extended pulling on the grips. This posture will release most of the weight from your front tire and will not allow your front tire to gather the initial traction to stop you. Instead, it will end up skidding.
CAUTION: If your front tire skids, IMMEDIATELY release the front brake.
Practice: Getting over rear skiddingRepeat the skidding exercise but use your FRONT BRAKE only.
You will notice that your braking distances are almost equal to your previous ones using both brakes. This is the demonstration that most of your braking power goes into your front tire.
Now try to apply the back brake again, just a little, a very little. If you skid you’re applying too much of it.
Practice: Slowing down on a steep slope.
- Find a paved, clean and dry steep path
- Gather a moderate speed.
- Adopt a balanced position off the saddle (see practice in Balance chapter).
- Progressively apply the brakes and slow down to a walking speed.
- With the slope you will be likely to skid more, so be very gentle on your back brake.
Try then to come to a complete stop on the slope’s steepest section. Try to hold your balance for one second (for this keep looking further down, don’t look at your bike), then release your brake and let it go.
Braking hard without skidding is essential to staying in control of your bike. You’ve discovered here how to balance your front and rear brakes, and how to avoid skidding. Braking balance will be essential later in many typical riding situations. Now that you also know how to counter the effect of mass transfer, you’re ready to hit a very wide range of obstacles. Bear in mind that you will use exactly the same braking skills going down a steep trail.