How to pivot a large motorcycle in a small space.
Step 1: The Problem
I've got a big motorcycle and a one-car garage that it lives in. I'd ride the motorcycle into the garage at the end of a ride, and then later to go for another ride I'd have to turn the motorcycle around. It's very big and heavy so doing a series of three-point turns was a serious invitation to lose control and drop the motorcycle. So what I wanted to do was turn the motorcycle 180 degrees, in place inside the garage.
This problem has arisen in various other forms in the past (for example, when moving: I'd ride the motorcycle into the back of a U-Haul truck and then be faced with the problem of getting it out again), so it's preyed on my mind for many years.
Step 2: Possible solutions
I started by imagining something like a railroad turntable in my garage! Hmm, we could jackhammer out a big circular depression (bigger than the bike), gouge out a ring-shaped trough at its circumference, put a bunch of huge ball-bearings into the trough, and lay a gigantic circular piece of steel in the depression, resting on the ball-bearings and flush with the floor. The bike would be driven into the garage and onto the piece of steel. To rotate the bike, rotate the whole piece of steel on the ball bearings, just like a railroad turntable.
Okay, so that's ridiculous; I'm obviously not going to mess up my garage floor...