I don't know of any tires that fit those 55 series wheels. I think there was a thread about that topic that lead to this conclusion. Since it already has the 23mm hex, you can use the pro-line wheels. I've installed the 40 series on my Genesis, but removed them because I have beadlock wheels and the tires always pulls away from the wheels. So if you're going 40 series, stick to glue.