I ordered new 12x3 Cheng Chin tires for my 700li and installed them last night. A couple of observations. First of all they are slightly larger than the original tires, which improves the overall look. The front rim is simple to remove. The back one requires a lot of work, including removing the chain, brake, side guards, and the seat so you can unwire the motor from the wiring harness. The tires fit very very tight and took some effort to get over the rim without damaging the aluminum. You also have to be very careful not to bend the hub bolts on the rear wheel as you are wrestling with it. I had to re-use the original rear bent stem tube as I was unable to find one. I installed a new heavy duty tube on the front.
I was amazed how soft the rubber is on these tires. My 700li rides much smoother than before, and there is no noticeable road noise. It might have picked up a km/h or two due to the larger diameter. Overall a very nice update!