show a mode where a power unit device is integral with a tread wheel which reduces mass and takes up less room there has always been a need for a lightweight human powered transportation device to extend the range of walking and better the speed to save time now environment protection emphasizes the need for non polluting transportation a comfortable simple to operate easy to mount and dismount transportation device extends the spectrum of users to casual weekend athletes there is a need for lightweight energy recovery and energy storage until useful so much of an operator 39 s energy is wasted and effort stressed unnecessarily by insight hard work and good fortune this novel invention has been inspired to satisfy all these needs to an extent never before thought possible concentrated urban areas will benefit the most as people who would normally drive their cars discover the incomparable exhilaration of rushing along silently under their own power of course claims define scope and elements of this disclosure include all the undisclosed parts necessary for their function all possible combinations apply 1 tread wheel 2 adjustable axle 3 drive wheel 4 a and 4 b controlling means 5 a and 5 b rear frame members 6 a and 6 b lower frame members 7 drive wheel axle 8 saddle tube inverted y shape 9 a and 9 b substantially vertical frame members 10 speed ratio mechanism pulley cluster 11 transmitting means a pulley cluster ratchet driving a tread wheel 12 shifting means derailleur.