Originally Posted by
LesterOfPuppets
Yep. Biopace et al were big in the mid-late 80s. IIRC my 400T had SR Sakae Ovaltech rings on it.
Your memory is right - Trek 400's (including the T model) of the time were specced with SR Oval-Tech cranksets & models higher up the line were Biopace
While we are on the subject...
Fun Fact: Sugino also offered its own elliptical crankset around the same time called Cycloid