Above all, the bike must be incredibly nimble in order to leap across gaps, or drop off from great heights. A lighter bike is desirable to make it easier to manoeuvre, but it goes without saying that this type of riding puts the bike in line for constant abuse from the constant bouncing, hopping and landings not to mention the inevitable misfortunes of crashing. Strength and durability are therefore paramount for the frame and wheels especially. Frames are usually very small, keeping them compact and strong, but also keeping them out of the way, so as not to impair the riders movements. Although 26 inch wheel trials bikes are used for competition, the smaller 20 inch size is used for purpose built trial machines. Wheels have wide rims often built with with more spokes than a standard wheel in order to increase their strength.
On a trials bike the tyres, especially the rear as many moves are performed with the front wheel off the ground, are critical to the overall performance, and must provide grip on a variety of surfaces, sometimes when there is very little surface to grip on. Because they are not ridden huge distances, like other forms of bike riding, trials tyres can benefit from softer rubber compounds and are run at very low tyre pressures, for maximum grip and to add a little cushioning for the rider. For this reason very wide tyres are used, to have a large volume of air, with a knobbly tread pattern to hook up on the edges of obstacles.
Brakes are a key element to many of the moves required in trials riding. Many trials techniques require the front or rear wheel, or sometimes both, to be completely locked. Individuals may have their own preferences but generally a hydraulic system is required, either as a disc brake, or hydraulic rim brake, to provide a very powerful brake. Gearing is generally low to provide a quick acceleration or pick up. Single speed is common, with a very small driving sprocket at the front. Sometimes trials bikes utilise a freewheel on the crank as opposed to the rear wheel to improve the speed of pick up. Wide handlebars are much better for control, so trials riders will use wide upswept bars for maximum leverage.