If you want to attach it to the bars, I'd say get a wodent wheel and hang it from the top of the cage. I have this (although have the largest wobust wheel) and it is as silent as you'll get - don't hear a thing except a faint swish. It depends on your cage - if you have a top door on the cage it depends where a wheel stand will sit without fouling up the top door. I find they work best hung upside down due to the gravity. When ours was stood on the cage floor it could move around and judder.
The Karlie Wonderland wood wheel is also virtually silent but sits on the cage floor. However it is very stable. I wouldn't put it on top of the substrate though in case a hamster tried to get under it, as they are heavy. I had my previous one directly on the cage floor and just sloped the substrate up away from it. It has a clear area in front of it and Charlie used to like running and then jumping out and flopping on the substrate.
The downside to the wood ones is they need checking for splinters - maybe a light sanding if there are rough areas, and then painting with a couple of coats of plastikote paint which helps waterproof them and seals any rough bits as well. You'll need the 29cm karlie wheel or the 27cm wodent wheel for a Syrian. Wodent wheels are hard to come by - in the Uk there is just the sugarglider shop or petplanet sometimes have them in stock in just blue and white.
11" Wodent Wheel (Senior) & Free Tail Guard
Wonderland Exercise Wheel: Great Small Pet Accessories at zooplus
This is our wobust wheel hung from the roof. You slot the stand through the top bars a few bars from the back (so it doesn't rub against the cage base where it slopes in), and attach the wheel to the stand inside the cage (or with the top off the cage). The top stand is held down with just 3 cable ties - I found this works best - it keeps it very stable. When I had lots of cable ties on it made the wheel hang at an angle.
Silent wheels
Linear Mode
