Hmm what could it be
If there were a mouse on that wheel, I’d say we were looking at Mike’s cranium from the inside …
Taking a guess, I’d say that belt drives a mechanism for a hanging arm. Knowing 25 that arm is probably long enough to legally attach to the bar from the pit area.
Well its obiously a timing belt idler, with the belt backward. But maybie its more than an idler. Does the key lie in the bearing? The gas strut i nthe background is a hint too.