1.3.020 For road, track and for cyclo-cross competitions, the frame of the bicycle shall be of a traditional pattern, i.e. built around a main triangle. It shall be constructed of straight or tapered tubular elements (which may be round, oval, flattened, teardrop shaped or otherwise in cross-section) such that the form of each element except the chain stays and the seat stays encloses a straight line. The elements of the frame shall be laid out such that the joining points shall follow the following pattern: the top tube (1) connects the top of the head tube (2) to the top of the seat tube (4); the seat tube shall connect to the bottom bracket shell; the down tube (3) shall connect the bottom bracket shell to the bottom of the head tube. The rear triangles shall be formed by the chain stays (6), the seat stays (5) and the seat tube (4) with the seat stays anchored to the seat tube at points falling within the limits laid down for the slope of the top tube. (See diagram «Shape (1)»). The seat post shall comply with the dimensional restrictions that apply to the seat tube and may be attached to the frame anywhere on the seat tube and/or top tube. (See diagram «Shape (2)»). 

The maximum height of the elements shall be 8 cm and the minimum thickness 1 cm. The minimum thickness of the elements of the front fork shall be 1 cm; these may be straight or curved (7). (See diagram «Shape (1)»). 

The top tube (1) may slope, provided that this element fits within a horizontal template defined by a maximum height of 16 cm. 

The effective width of the head tube zone may not exceed 16 cm at the narrowest point between the inner join of the top tube and down tube and the front of the box for the head tube. 

Additional frame components can be added between the head tube and the handlebar stem. These must be inside the dimension of the head tube box. 

Isosceles compensation triangles with two 8 cm sides are authorized at the joints between frame elements except at the joints between the chain stays and seat stays where triangles are not authorised (See diagram «Shape (3)»). 

(text modified on 07.06.00; 01.01.05; 01.02.12; 01.01.16; 01.01.21) 

