One Wheel
Legend
I've actually prepared ferrofluid in college, so I know about this!
Here are a few issues:
1. Some ferrofluids are extremely caustic, this is because of tetramethyl ammonium, and they will burn your entire nasal tract down to your throat if you sniff it. I made the huge mistake of sniffing it once...
2. The rockwell hardness of the iron particles is much greater than the plastic, and it'll wear away at the plastic. This might help to break it in though, especially at such a small particle size, hmmm... maybe good!
3. Over time, ferrofluid dies, and dries up into metal particles and gunk.
It's an interesting concept, lubes that slow down or speed up in the presence of magnetic force, interesting thought!
Bummer! Ah well, it's a cool thought if it would work. Maybe someday of you figure out an alternate method of doing it and want to credit me with the idea that made you a billionaire you can send me a bottle to test