We Use a 1-Seater Bike Trailer
I bought a 1 Child Seater Red Bike Trailer for about 100 bucks...it had great reviews, it was put together fairly easily, and it holds up. Nina absolutely LOVES being pulled in it, whether its attached to the bike or if you're just pulling it by hand. I looked up the differences between baby bike seats and trailers, and the trailer just seemed safer. If the bike tips, the trailer stays relatively upright. It doesn't affect the weight of the actual bike for turning, it's just you might wanna change gears on the bike. I always use the highest gear my bike has, and towing nina along makes it a little harder, but it's good exercise and we both enjoy it. It has a plastic window to roll over the regular net/door, for when it rains or to keep out dust or dirt or bugs. There's a pocket in back for a diaper bag or purse or whatever. I've seen some people toy pets along in them, lol. Overall, we love our bike trailer.