An exercise bike may include a magnetic braking system to resist rotation of a flywheel. The magnetic braking system may be magnets mounted on brackets selectively pivoted relative to the frame to increase or decrease the resistance opposing rotation of the flywheel. The brackets may be pivoted using a brake adjustment assembly joined to the brackets in such a manner that the magnetic forces resisting rotation of the flywheel increase or decrease in a proportional manner over at least a portion of the adjustment range of the brake adjustment assembly. The exercise bike may further include a console that displays information, such as power. The power may be estimated from a look-up table using the crank or flywheel speed of the exercise bike measured using a speed sensor and the tilt angle of the brackets relative to a reference point measured using a power sensor that includes an accelerometer.
1. An exercise bike, comprising:
a frame;
a drive train operatively associated with the frame;
a flywheel operatively associated with the drive train; and
a braking assembly comprising:
an elongated adjustment member defining a longitudinal axis;
a friction brake operatively associated with the elongated adjustment member, wherein pressing down on the elongated adjustment member engages the friction brake with the flywheel
a magnetic brake comprising:
a first bracket joined to at least one first magnet, operatively associated with the frame, and positioned proximate the flywheel; and
a second bracket joined to at least one second magnet, operatively associated with the frame, and positioned proximate the flywheel; and
a link assembly including at least one link operatively associated with the elongated, adjustment member, the first bracket, and the second bracket;
wherein the elongated adjustment member, the magnetic brake and the link assembly are configured such that rotation of the elongated adjustment member around the longitudinal axis of the elongated adjustment member causes the first bracket and the second bracket to pivot in the same direction and moves the first bracket and the second bracket via the at least one link between at least first and second positions where at the first position the at least one first magnet and the at least one second magnet at least partially overlap the flywheel to operatively associate the magnetic brake with the flywheel and at the second position the at least one first magnet and the at least one second magnet do not overlap the flywheel to operatively disassociate the magnetic brake with the flywheel,
2. The exercise bike of claim 1 , wherein the flywheel includes an inner radial portion formed of a first type of material and an outer radial portion formed of a second type of material different than the first type of material.
3. The exercise bike claim 2 , wherein the second type of material comprises a non-ferrous, conductive material,
4. The exercise bike claim 3 , wherein the first type of material comprises steel second the type of comprises aluminum.
5. The exercise bike of claim 1 , wherein the first bracket and the second bracket pivot about a common pivoting axis.
6. The exercise bike of claim 5 , wherein the common pivoting axis of the first bracket and the second bracket is substantially parallel to a rotating axis of the flywheel.
7. The exercise bike of claim 5 , wherein the common pivoting axis of the first bracket and the second bracket is above a rotating axis of the flywheel.
8. The exercise bike of claim 5 , wherein the common pivoting axis of the first bracket and the second bracket is above and outside an outer radial surface of the flywheel.
9. The exercise bike of claim 5 , wherein when the first bracket and the second bracket move towards the first position to operatively associate the magnetic brake with the flywheel, the first bracket and the second bracket pivot about the common pivoting axis in a first direction; when the first bracket and the second bracket move towards the second position to operatively disassociate the magnetic brake with the flywheel, the first bracket and the second bracket pivot about the common pivoting axis in a second direction that is opposite the first direction.
10. The exercise bike of claim 1 , wherein the link assembly further includes a link plate including a hole that receives the elongated adjustment member therethrough, the at least one link is operatively associated with the elongated adjustment member by pivotally joining the at least one link to the link plate, and the at least one link is operatively associated with the first bracket by pivotally joining the at least one link to the first bracket,
11. The exercise bike of claim 10 , wherein:
the at least one link defines a link longitudinal axis;
in the second position, the link longitudinal axis extends at an angle from the longitudinal axis of the elongated adjustment member; and
as the first and second brackets move from the second position to the first position, the at least one link pivots relative to the link plate and the first bracket in such a manner that the link longitudinal axis more closely aligns with the longitudinal axis of the elongated adjustment. member at the first position than at the second position.
12. The exercise bike of claim 1 , wherein the elongated adjustment member, the magnetic brake, and the link assembly are further configured such that for at least a portion of an adjustment range, an incremental rotation of the elongated adjustment member causes a substantially proportional change in a resistance exerted by the magnetic brake on the flywheel.
13. The exercise bike of claim 1 , wherein the friction brake comprises a brake pad joined to the first bracket and the second bracket, and the brake pad includes a curved surface that conforms to an outer surface of the flywheel
14. The exercise bike of claim 1 , wherein when at the first position, at least a portion of the flywheel is positioned between the first bracket and the second bracket.
15. The exercise bike of claim 1 , wherein when at the second position, at least a portion of the first bracket and at least a portion of the second bracket are located above an outer radial surface of the flywheel,
16. The exercise bike of claim 1 , wherein when the first bracket and the second bracket move towards the first position to operatively associate the magnetic brake with the flywheel, the first bracket and the second bracket move towards a rotating axis of the flywheel.
17. The exercise bike of claim 1 , wherein when the first bracket and the second bracket move towards the second position to operatively disassociate the magnetic brake with the flywheel, the first bracket and the second bracket move away from a rotating axis of the flywheel.