frame is done by movement of the steering gear application_number US 72485510 A description as described in the inventor 39 s earlier applications exercise during controlled instability provides positive health results and qualities to a person 39 s muscles tendons and overall balance of the body both during strength training and during rehabilitation after an injury the following description will show how an exercise apparatus in the form of an exercise bicycle for indoor use is designed to give a person simulated experience as if using a more ordinary mobile bicycle fig1 show an exercise apparatus representing an indoor stationary exercise bicycle including a first lower frame 1 stable relative to a floor which supports a second upper frame 2 which is tiltable attached to the first frame 1 as shown in fig2 and 3 the second upper frame 2 is tiltable through axis 4 relative to the first lower frame and the floor bearings not shown connecting the two frames 1 and 2 are positioned in the forward 5 and rear 6 part of the frames the bearings being of for example slide bearings or ball bearings tilt motion is indicated by arrow 7 a flywheel 10 is rotatable fastened to the upper frame 2 connected to drive means as a belt or a chain 11 which via a cog or sprocket 12 transfers motion to the flywheel through a crank 13 with pedals 14 and 15 the drive means are mechanically similar to that of prior art and is therefore not shown in more detail on the figures thus will not be commented any further a seat 17 is fixed on the upper frame 2 in a familiar manner.