Carl B. Latro

reading some technology reporting today and they're using the term flywheel, a pet peeve of mine. I have written about this before on some ephemeral social media, but I am moved now to repeat my objection in a place of greater posterity.

the word "flywheel" seems to have entered the business-writing lexicon with a book about amazon called "good to great". I have not read this and have no intention of reading it. perhaps the metaphor was used sensibly there. it is no longer used sensibly. here are a couple representative samples I just found via google of the way it is used nowadays (emphasis mine):

By definition, a flywheel is a heavy revolving wheel that is used in a machine to increase momentum and therefore provide greater stability to the machine. Given its weight, the flywheel is difficult to push from a standstill, but once it starts moving it gradually builds momentum, which eventually enables the wheel to turn by itself and create even more of its own momentum through a self-reinforcing loop.

or:

A flywheel is a massive metal disk, or wheel, that often weighs over 2,000 kgs. It takes a lot of effort to get it started, but once it starts to turn there are counterweights around the outside of the wheel that start to take effect and it starts to build momentum almost by itself. From that point, the same effort can be placed on the flywheel and it will start to turn faster and faster.

this is characteristic of the way people use the term now. they talk about "getting the flywheel going" on their business, because once you're over some kind of threshold the flywheel will somehow magically start spinning faster and faster on its own.

that is not what a flywheel is or what it does at all.

a flywheel is a kinetic battery. you put angular momentum into it when you have a surplus and you can take some back out when you have a deficit (assuming friction hasn't lost it all yet). other metaphors that have a similar effect are account balances, or warehouse inventory, or queues. or taking an average of something noisy over time. take your pick.

a wheel that somehow went faster of its own volition would be a perpetual motion machine. a fantastical solution to all the world's energy needs. but also fairly prohibited by .. physics. there is no such thing.

people using the metaphor this way seem to be getting it confused with positive feedback phenomena. which do exist! even in business! here is a classic one: sales volume up => unit production cost down => sale price down => customer demand up => sales volume further up. a.k.a. "economies of scale". great stuff, bravo capitalism. it has some other positive feedback loops that are not so great like "overproduction crisis" or "market panic" but we need not dwell on those.

there are also lots of other non-capitalism examples of positive feedback phenomena. population growth, cytokine storms, even the digital flip-flop circuits storing this post are positive feedback systems.

but: a flywheel is not a positive feedback system. not at all. please, I beg you: for pity sake stop using it as a muddled metaphor for one.