stays 22 slope upward from the rearward standard 20 to the forward standard 20 other seat supporting and elevating constructions can be used if desired a seat 24 is positioned above and supported by the seat standards 20 in the illustrated arrangement the seat 24 preferably is positioned over a slide plate 26 that is mounted to the seat standards 20 the slide plate 26 can be mounted at an angle a to horizontal h see fig4 and 7 by mounting the slide plate 26 at an angle the seat can be adjusted both toward the pedals and up and down in a manner that allows proper ergonomics to be achieved the seat 24 preferably engages the slide plate 26 in a manner that secures the seat from being lifted from the slide plate 26 in one embodiment the seat 24 can be mounted on rollers 27 that roll within a channel formed in the slide plate 26 or the slide plate can contain rollers over which a rail connected to a portion of the seat 24 rolls other manners of allowing the seat to translate also can be used the slide plate 26 comprises inwardly extending channels that are positioned on the lateral sides of the plate 26 a framework 28 is supported by rollers 27 that are positioned within the channels such that the framework 28 can be formed fore and aft along the slide plate 26 this arrangement allows the slide to be adjusted forward and rearward in any suitable manner in one arrangement a seat lock 29 has a handle 31 that.