We are surprised at how much these solid comfort tires improve the comfort of the ride on my wife's new segway. We have been riding segways for some years now. This one replaces he original machine which she wore out. She got the S-Max for the increased range. We are delighted at the improvement in that respect. However, we are upset that Ninebot markets its S-Max with those ridiculous solid tires as if everyone who buys the S-Max will want to get the go cart as well. Not! So we had to pay an extra hundred dollars just to get a ride that we feel should have come with our purchase. (A side note: we made the mistake of buying our segway on Amazon instead of at Segway Los Angeles. Who knows what sort of deal Segway of Los Angeles would have worked out with us had we purchased our machine there?) The tires: 5 stars. Segway Los Angeles: 5 stars. Segway: 5 stars...if our Segway had come with these comfort tires, otherwise, 2 stars.