Adon
2018-07-21
My wife and I have used this: https://www.topeak.com/global/en/products/child-carrier
We bought one seat and two racks, one rack for each of our bikes so we could just switch the seat and not the rack.
There are a lot of nicer looking seats out there (and maybe more expensive, too), but we've found this to be perfectly fine.
We bought one seat/two racks 7 years ago, and our youngest, so it's been through an older kiddo and is not on kiddo #2 who is two and a half and loves it.
Here are even a few links to used sets on CL: https://portland.craigslist.org/search/sss?query=topeak%20baby%20seat&sort=rel
Hope this helps.