Rim brake system and a tire

A rim brake system for a wheel having a wheel rim, comprising:

• at least one brake element;
• a frame holding at the least one brake element with a rim-bearing face that faces the wheel rim;
• each of the at least one brake element being capable of reciprocating in a forward-rearward direction between front and rear positions and being biased by at least one first urging element into the front position, the elements being configured such that in their rear position the rim-bearing faces are distanced from the rim, while bearing on the rim in the front position;
• an actuation element associated with a second urging element that can be displaced between first and second states and biased into the first state in which it forces the braking elements to be in their rear position against the bias of the first urging element;
• and
• a user-operable actuation mechanism configured to switch the actuation element into its second state, whereby the brake element is free to move into its front position.