Over the Bars (OTB) One of a beginners most feared events on (or rather off) the bike is an unplanned trip over the handlebars. Two things cause this. First is the front wheel suddenly stopping or slowing too quickly, and second is poor weight balance. Reasons for the front wheel stopping too quickly include pulling too hard on the front brake and putting the front wheel in a hole or dip it cannot easily roll out of. Both are relatively easy to avoid with a little attention. Adjusting weight balance to avoid a trip over the bars is a skill which can be mastered with a little practice.

 Balance is Crucial To balance properly on your bike start with the ready position. Body weight should be evenly distributed on the left and right side of the bike. For complete stability think about forward/back weight balance in addition to lateral weight distribution. A trip over the bars is a big uncontrolled forward weight shift. Most of the mass in your body is located in your torso. Hands and feet are fixed on the bars and pedals. Weight shifting is accomplished by moving your torso around. 

Center of Gravity To have perfect balance your center of gravity should fall at a point on the ground halfway between the front and rear wheel. On flat ground that is accomplished with a normal seated riding position and also the ready position. 

Balance Visualization Imagine a flashlight tied on a string, dangling from the front of your waist. Where the light shines on the ground is where your center of gravity falls.

Uphill Balance If you do not weight shift when the terrain heads uphill your center of gravity will fall back over the rear wheel. Your front wheel will begin to pop up or become light and wobbly. This will cause you to lose traction with the ground, become too unbalanced to power the pedals and probably not make it up the hill. So you climb off, push your bike up and climb back on. Meanwhile your buddies are two minutes up the trail having expended less energy than you!

Descending  Most over the bar spills occur when the terrain heads downhill. Pointing a bike downhill moves your center of gravity forward. Weight must be shifted back to keep it balanced between the two wheels.

How to shift your weight on the bike There are actually many different methods.  A key common point to each method is to keep your arms and legs bent and whenever possible lower your center of gravity by bringing your torso down towards your frame.

To weight shift forward you can remain seated or be out of the saddle. Bring your sternum (breast bone) close down towards your stem. Keep your elbows tucked in and low. To weight shift back you must raise your butt out of the saddle and move your hips back. Remember to also lower your center of gravity by lowering your torso down towards your frame.  Keep your arms bent – a must for steering. 

Steep Downhills  As the downhill becomes steeper you need to shift your weight further and further back and lower you center of gravity more. At the extreme position you can be so far back your seat is at your chest and your hips so low the rear tire will buzz your butt. If you try this be sure to keep your arms bent. I doubt that in this position it is possible to fly over the handle bars. 

Practice these positions on flat ground in a traffic free area. See how flexible you can be and how far you can move around over the bike. It is very hard to get back far enough to buzz your butt on the rear tire – give that a go, you might like it!!