The chassis features extra holes which allows to move the whole suspension more forward to extend the wheelbase of the car. The chassis features 3 wheelbase adjustment positions. The full backward position is identical to the original X1 chassis wheelbase. The other two extra positions extends the wheelbase of the car by 4 and 8mm. The longer the wheelbase is, the car is more stable and easier to drive. However longer wheelbase decreases car response, rotation and steering. Shorter wheelbase is recommended for smaller technical tracks and longer for more open tracks. The 2.5mm chassis & top deck are made from high quality graphite material.