I primarily use my road bike to pull my son in a trailer - a Bianchi Sport SX (I think). It has no granny gear - which really stinks, but when I ride regularly it builds my leg muscles - getting up hills is rough though. I've never had a problem. I occasionly use a really old Schwinn (a bike I got in the sixth grade that somehow still fits me) hybrid bike. This is more comfy for me, but the bike is in such bad condition I don't like to be seen in public with it.