72 and 74 extending to each of the front wheels 42 respectively in a conventional manner which will not be described herein adjustment of the steering beam 70 results in concomitant movement of the steering bars 72 and 74 which through the various pivot connections steer the front wheels the present invention may however use any other steering mechanism which may be convenient a main drive roller 76 is mounted on the main drive roller bar 50 when mounted on the mower frame 12 the rear wheel 20 of the bicycle is in contact with the main drive roller 76 best illustrated in fig1 of the drawings the bicycle rear axle supports 56 and 58 are fixed to the rear wheel axle 28 of the bicycle in such a way as to insure that the rear wheel is firmly in contact with the main drive roller 76 the main drive roller 76 when rotated drives a shaft 78 and sprocket 80 the first mesh gear bar 52 has mounted thereon a first mesh gear 82 and a shaft 84 the second mesh gear bar 54 has mounted thereon a second mesh gear 86 and a shaft 88 the first mesh gear 82 and second mesh gear 86 are of a size and spaced from each other such that they are permanently engaged the main drive roller 76 drives shaft 78 and sprocket 80 a chain 90 extends between the sprocket 80 and a sprocket 92 on the shaft 88 at the.