Chris Filkins – Venice, CA. Etsy web page — Chris makes excellent wheels. He tends to use short solid steel inserts.
Hugo Noel / Circus Concepts - Canada. circusconcepts.com. I haven’t met Hugo, but I’ve seen his new wheels and they are excellent. I believe he uses steel inserts.
Backstage Fab: http://backstagefab.com/CustomWheels.html — I haven’t seen their wheels personally and don’t know much about them. But they look pretty.
Daniel Cyr: http://www.cirque-eloize.com/en/who-are-we/the-cyr-wheel – The originator of the cyr wheel, as we know it. I’ve heard he may not be making wheels anymore.
RB Workshop: http://ateliersrb.com – Located in Quebec – word is they have good wheels, but I haven’t seen them. The man who makes them has a daughter (Valerie Inertie) who uses his wheels, and has been doing high level cyr wheel work for many many years, so I’m sure they are well made.
FireToys (UK): http://www.firetoys.co.uk/balance-props/cyr-wheels-german-wheels.html — I heard their wheels aren’t that good from one source, but that may have changed.
Juggle Gear: http://www.jugglegear.com — I haven’t heard much about these wheels.
Contact me if you want me to add your company or name to this list.