Six months is young, no doubt about it, but I know of plenty of people who cycled with their LOs, even younger than that. I think it really depends on:1. your child's development.
You might check with your pedi and get his/her opinion on where your LO one stands, developmentally. Ask specifically about this activity which will include a degree of bouncing.2. your intentions as a cyclist
(smooth pavement vs trails; daily vs weekends only; 10 mph vs 20 mph; 5 miles vs 45 miles, heavy traffic vs cows, etc)3. the equipment you have available to you.
The two most popular ways of transporting LOs in this country is via bike seats or trailers. Not all trailers are created equal. Suspension systems, air ventilation, wheel types all have a huge impact on the comfort and safety of child inside. Some parents have installed infant car seats into their trailers to help provide a safer ride. Here is some helpful info about different methods of cycling with your LO:http://hea-www.harvard.edu/~fine/opi...dcarriers.htmlhttp://www.bhsi.org/little1s.htmhttp://www.ibike.org/education/infant.htm
Giro and Specialized both make helmets for kids under the age of three.4. the laws in your state and community.
State law where I live specifically states the following:
a. If you carry children or other passengers inside an enclosed trailer or other device that will adequately restrain them and protect their heads in a crash, they need not wear helmets.
b. You may not carry any child between the ages of 1 to 4, or weighing 40 pounds or less, anywhere on a single-passenger bike except in a baby seat attached to the bike. The child must be able to sit upright in the seat and must be held in the seat by a harness or seatbelt. Their hands and feet must be out of reach of the wheel spokes.
c. You may not carry any child under the age of 1 on your bike, even in a baby seat; this does not preclude carrying them in a trailer.
Soooo... under age of 1, child must be in trailer (NOT in bike seat). While in trailer child does NOT need to wear a helmet. Why? You ask? Because a good trailer not only has the steel cage covered in fabric surrounding them, but they are also secured by a 5-point harness. I know of parents who have picked up the trailer and turned it over (not riding bikes at the moment) just to see how secure their LO is in there. Good trailers aren't going to tip anyway, even if the bike does, but it is nice to know your precious cargo is safe back there!
PM me if I can help at all. I kinda researched this topic to death a couple of months ago.