Firstly, you need to think of a way to get all your bikes to the location and the best way to do this is normally with one or several push bike racks for cars. You can always set off from your home and ride in your area, or ride to the scenic area you want to drive in. However for most of us who live in urban areas this isn’t always very scenic – it also probably means riding on the road which can be dangerous and if you have children. Additionally you’ll be cycling in single file which ruins the sociable nature of the activity somewhat. Then when you get to your actual location you might be very tired. Using one or several bike racks then can be a much better idea as it enables you to store the bikes on top of the car and drive to your location. You can also store other items in the car such as picnic items, a torch if it might get dark, a first aid kit etc etc. This also means that you won’t have to be squashed in next to a large bicycle. Another alternative is to rent bikes when you arrive, which is fairly cost effective, though you risk being lumbered with a bike that you’re not comfortable with.
And that’s another point to consider – making sure that all the bikes are in good condition and that they’re suitable for the terrain you’re going to be riding on. If you’re riding on pavement then racing bikes are a good idea as these are very quick and require the most minimal effort. If you’re going to be riding up hills and across bumpy terrain however then you’re going to need to use a mountain bike. Make sure as well that all the bikes are in top condition – that all the gears work and that the tyres are fully pumped up. If you do not, then you risk someone lagging behind at the back and having to put in a lot of extra effort which can be unpleasant for them. By checking in advance you ensure this isn’t the case and that everyone can enjoy a smooth ride. Obviously you may need to supply stabilisers or a tricycle for some of the less confident cyclists.