Wheel-type resistance device for a bicycle exerciser

A wheel-type resistance device for providing a resisting force to a bicycle exerciser which includes an axle defining an axial direction, and a hub member mounted rotatably on the axle and driven to rotate by a pedaling action of a user, said wheel-type resistance device comprising:

• a flywheel having left and right end walls, said flywheel being adapted to be mounted rotatably on the axle such that said left end wall is proximate to and is rotated together with the hub member around the axle, and such that said right end wall is distal to the hub member, said right end wall having an accommodation chamber therein indented axially and leftward so as to form a dragging force generating wall which is spaced apart from said right end wall in the axial direction and which has a first circumferential portion extending in a radial direction relative to the axle;
• an angular magnetically attractive member disposed on said first circumferential portion;
• a dragging force adjusting member adapted to be mounted on the axle and having a right major surface and a left major surface which is spaced apart from and opposing said dragging force generating wall and which is provided with a second circumferential portion that is registered with said first circumferential portion;
• upper and lower magnetic members disposed movably on said second circumferential portion and spaced apart from and in symmetry with each other relative to a horizontal line transverse to the axial direction;
• an actuating member connected to said upper and lower magnetic members for actuating linear movement of said upper and lower magnetic members toward the horizontal line along a transverse direction relative to the horizontal line so as to decrease extent of overlapping of said upper and lower magnetic members with said second circumferential portion;
• at least one first keyway disposed on said dragging force adjusting member and extending in the transverse direction toward the horizontal line;
• at least one first key disposed on each of said upper and lower magnetic members and inserted into and guided by said first keyway to assure the linear movement of said upper and lower magnetic members;
• and
• means for biasing said upper and lower magnetic members to increase the extent of overlapping thereof with said second circumferential portion against action of said actuating member.