I like the bike, but the tire setting are on 23 for a 26 inch tire. There are many S830 settings that are incorrect and locked. It will do 23mph on the flat with a fully charged battery. "Unlocking" the speed limit changes nothing. I have a friend with the C05 model. I unlocked the speed limit for him. He can now go about 28mph. It must be because the YY26 is so darn heavy. I would not recommend this bike to anyone under 5'10" I'm happy that the battery charges quickly because the battery runs out much faster than advertised. It's built very well. The stock seat is surprisingly comfortable. It's even softer and more comfortable than the aftermarket seat I had planned on using. Using the thumb throttle is a breeze and requires little effort to operate, and in my opinion, far better than twist throttles. Just rest your palm lightly on the throttle lever and glide effortlessly. Self-assembly was a breeze. All of the parts shout quality, down to the last bolt. I get a lot of compliments. People have many questions. It was delivered very quickly and came in perfect condition. There aren't direction on how the bike controls operate and or to set the controller. With the many Youtube instructional videos available, that's really not a big deal. Overall, it is a good bike and worth the money. The money is put into the bicycle, not extras like racks and baskets. I recommend the suspension seat post for a smoother ride.