to offer you some insight... I do not like trixie wheels, as lots of people including me. has had issues, most of the time you can modify the wheel to make it function better, but for me it isn't worth it... the wheel is loud and hits the stand (for alot of people)... you can also hang it upside down and secure it with zip ties etc that some say fix lots of the problems but still.. would avoid the hassle.
Unless you get the wooden trixie wheel, that is abit better, but also bad if your hamster decides to pee on it, as if it soaks into the wood it will be impossible to clean, to get rid of the smell, so the only solution is using Plastikote on it, it's basically a pet safe paint you can get in clear or various colors, to water proof the wheel for easy cleaning...
The wheel I have is a plastic wheel, so easy to clean etc, but mine I bought from Ebay and is a DIY wheel someone makes and sells, but It's very well made and my hamster loves it.. here's a video of it if you're curious (Yes the person who sells them does pink as well! however if you did want to go down that route, make sure you have the space, all though it's a 12 inch wheel, the wheel has a deeper depth then most typical wheels so takes up a little more space.
https://www.youtube.com/watch?v=zcTaW-82iGY
but spite that, what sushi says is correct, for a Syrian, you for sure what an 28 cm /12 inch wheel, sure if yours is just baby a small wheel like 8 inch is minimal, however I'd still go for the big 12 inch wheel, as if your hamster is still young he/she will grow into it, my hamster is like over a month old ish, and as you can see, he is running on the 12 inch wheel fine, so I do suggest going straight to the best size for a Syrian!