Why Use A Short Steam-Wide Bar Combination?
It’s all about bike control. Shorter stems center your weight and quicken the steering response. Wider bars give you more leverage and more control over the steering. A wider bar will shift more of your weight forward and the shorter stem will compensate for this.
When you pair a short stem with wide bars you are increasing your leverage and reducing the force rocks and roots can exert on the front wheel. Moving your bars back with a shorter stem gives you a better center of gravity on your bike which lets you tackle steeper sections with confidence and less chance of being pitched over the bars. Also, you can tip the bike into corners further while remaining centered over the bike for better grip.
What Width Bar / Length Stem To Use?
The general rule of thumb is to maintain a 2:1 ratio of handlebar width to stem length. For every 20mm increase in handlebar width you should reduce your stem length by 10mm. So if you’re running 660mm bars with a 100mm stem and want to try a handlebar that is 720mm wide you will need to pair that 720mm handlebar with an 70mm stem to maintain a relatively consistent position on the bike.
Like most rules of thumb, this 2:1 ratio is by no means absolute and it is only useful if you’re starting from a comfortable fit position.
It’s easy to experiment with handlebar width, with a wider bar installed, mount your controls and if after going for a ride the bars feel too wide gradually move the controls inboard until you find a position that’s to your liking.