I'm still on a wheel research mission! Just for the heck of it really. So the Niteangel wheels. I'm not sure it's worth all the extra cost to ship one to the Uk. That makes it a really expensive wheel. They look really nice. But there are also a lot of negative reviews that say they stop being silent after a few months (maybe need oiling) and one that the wheel just shattered (probably a rare thing). About £63 in the Uk!
We have the wood cork wheels by Getzoo and Rodipet available that work out cheaper and they're not cheap at about £45 (but plastic is easier to clean long term). And Rodipet seem to be permanently out of stock. I prefer the design of the Rodipet to the Getzoo as they have no lip but it's a minor thing. I do like the cork running surface on those.
Neither of these will fix easily to cage bars without some adaption - except the small ones. Pip has the 21cm rodipet wheel and I just screwed it to the bars as it is - works fine and still silent. It tips very slightly forwards - that would be more of an issue with the larger ones.
I'll wait for Cloudy to give us feedback on the TicTac wheels
They are at least designed to attach to bars. About the same price as the Rodipet and Getzoo wheels (on offer price anyway).
Meanwhile I've just had a lime green Trixie 28cm wheel delivered as my spare wheel/playpen wheel at £12!. Don't want to not have a spare wheel again. I appreciate them more seeing the costs of the others!
Silent runners are still good of course but I am very iffy about those little gaps. I've emailed the manufacturer to say it didn't used to be like that, is that right? And has manufacture changed.
In reality the gap doesn't go all the way through - the base is behind it, and it it's unlikely a toe would get caught - but I don't like the gaps. A wheel surface should be solid and no gaps.
We also still have the Trixie Wood wheel in the Uk at £20 odd on Amazon or cheaper on Zooplus. A lot of people have complained about the quality of these recently - me included. I sent mine back and got the Karlie Wonderland one from Amazon for about £23 - which looks identical! But they do seem to be better made.
I liked that wheel hung upside down but that won't work on the Plaza cage due to the edge strips being in the way a bit. And it would pull at the lid too much.
So lots of choice for silent free standing wheels but not a huge choice for bar mounted wheels without adaptation.