Kids' bike trailers are safe alternatives to bike-mounted kids' seats, though they can be more expensive. When choosing the best one for your needs, first decide how you are most likely to use it. Kids' bike trailers can usually accommodate either one child or two children, so be sure to buy the appropriate size. Some trailers will convert from a trailer into a stroller as well, making them a versatile choice for both bike rides and runs along the walking path.
The enclosures included with kids' bike trailers should be made from durable materials such as rip-stop nylon or other heavy-duty synthetic materials that will resist tearing. It helps if this material is waterproof or water-resistant as well so the child stays dry and comfortable in all weather. Many kids' bike trailers feature a flap that can be secured down to completely enclose the child, and it can be fastened up to allow the child to be exposed to the open air. A plastic window is often built into this flap to allow the child to see out and the parent to see in, even when the flap is closed.
Make sure any kids' bike trailers you are considering have strong, sturdy frames and an easy method for attaching or detaching the unit from the bicycle. The point of attachment should protect the bicycle as well, preventing scratching, gouging, or other damage that can compromise the strength of the bike. Many kids' bike trailers feature a quick-release function that allows the user to attach and detach the trailer quickly. Look for such a feature to make the process much easier on you. The frame itself should be made of high-grade metal, though it is helpful to choose a frame that is not too heavy.
The wheels of the kids' bike trailers you are considering should be easily installed and removed. This will make both the intitial assembly and changing flat tires much easier. Make sure the wheels are a common size so you will be able to purchase replacement tubes and tires easily when necessary. Uncommon sizes will make the purchase of replacement parts much more difficult. Larger wheels will allow you to ride off-road, while smaller wheels will only be appropriate for on-road use. Be sure to determine what kind of riding you will be doing before purchasing a trailer.