Bicycle Head X-Rubi I 29", Size 20.5" (52cm), Black/Orange

The frame is made stronger than other types of bikes, and is designed for the best possible rideability. The geometry can be chosen for optimum stability or manoeuvrability.

Wheel sizes can be varied according to the purpose of the ride. 26" wheels are usually used for more challenging trail sections. These wheels are the strongest and most manoeuvrable, but have poorer rolling characteristics compared to discs. The 27.5" size is ideal for maintaining the ratio of manoeuvrability to stability. Many manufacturers use these wheels on low-frame bikes to maintain good rolling characteristics and a low centre of gravity. 29" wheels are used on most mountain bikes. They have good rolling characteristics and slightly improve shock absorption.

Wide tyres with deep tread, chosen according to the surface conditions - a narrower and rougher tyre is best for sand, while a wider tyre with a smoother tread is better for a more efficient and more comfortable ride.

The rim is open for easier access for cleaning and changing. This is important because the higher load of the mountain bike chain will cause the chain to wear out more quickly.

Mudguards are less commonly available, but are essential for clean clothing and comfortable riding in the rain, and can be fitted as an option.

The saddle is narrow - for a firm and flexible enough seat for uphill pedalling.

Made with both dynamos for comfort and with separate battery-powered lights to maintain a lighter construction.