Possible to do multi-speed transmission with v-belt?

[RogerR]

team 694 used this method to turn the kit bot into a two speed drive train. there's a thread, but all the links are broken. i do have one of their promo videos, which shows the bot shifting, but its too large to upload.

they modified the frame to run 6 wheels, and all the wheels on one side a connected using belts. the front and back wheels are also connected to the kit gearbox, but the gear ratio is different for the front and back wheels, and the gearbox moves back and forth, tensioning one belt and loosening the other when its moved in one direction by a pneumatic cylinder, and vice versa when its moved the other. a very simple and elegant drive train; one of my favorites.