Every competitor must ensure that his machine is so constructed, equipped and maintained as to be capable of being ridden on the road safely at all times and in all conditions. The riding position shall be set so that the competitor has good forward vision when in a competitive position. In particular but without prejudice to the general principles of this regulation:
(a) Brake levers must be secured to the handlebars in such a position as to enable the competitor to readily apply both brakes whilst holding the handlebars at their widest point. The width of handlebars shall be no less than 35 cms.
(b) On tricycles and tandem tricycles, two brakes may operate on the front wheel but otherwise the braking systems must operate independently on both front and rear wheels.
(c) Bicycles with a fixed wheel shall have a left hand threaded locking device securing the fixed sprocket. Similarly, tricycles with a fixed wheel shall have a suitable locking device or alternatively shall include an integral system as part of the design. Machines with fixed wheel require only a brake operating on the front wheel(s).
http://www.cyclingtimetrials.org.uk/Regulations
COMPETITOR
Every competitor must ensure that his machine is so constructed, equipped and maintained as to be capable of being ridden on the road safely at all times and in all conditions. The riding position shall be set so that the competitor has good forward vision when in a competitive position. In particular but without prejudice to the general principles of this regulation:
(a) Brake levers must be secured to the handlebars in such a position as to enable the competitor to readily apply both brakes whilst holding the handlebars at their widest point. The width of handlebars shall be no less than 35 cms.
(b) On tricycles and tandem tricycles, two brakes may operate on the front wheel but otherwise the braking systems must operate independently on both front and rear wheels.
(c) Bicycles with a fixed wheel shall have a left hand threaded locking device securing the fixed sprocket. Similarly, tricycles with a fixed wheel shall have a suitable locking device or alternatively shall include an integral system as part of the design. Machines with fixed wheel require only a brake operating on the front wheel(s).