Plastic jumping bean track type thing

So many toys from the 70s conjure up images of people at large toy companies sitting about in boardrooms trying to dream up ideas for the next thing they can persuade a viable number of kids to pester their parents into buying, if only the TV ads are jazzy enough. One such thing was this clunky contraption, which I've forgotten the name of. It consisted of three plastic plank-type things, about a foot long, each with four semi-circular grooves running the length of it, and a hole at each corner on the top and bottom where a rod of dowelling fit in, so you could connect the three planks together and stand the thing on the floor. Now came the fun part. you had four plastic bean-shaped things - a plastic shell containing a ball-bearing - that would roll end-over-end down this track. You had to set them off at once and race them.
That was it. It got dull pretty quicky as you can imagine, but I bet the TV ads made it look fantastic.