I need to transport an "open frame" bike on a Saris Bones 3 car rack. This is the bike - http://arragons.com/online-store/bikes/hybrid-bikes/ridgeback-element-open-frame - and this is the rack - http://www.wiggle.co.uk/saris-bones-3-bike-rack/.
I'd like to like to know whether I need to shell out for one of these bars - http://www.wiggle.co.uk/saris-bike-beam-bar/ - which create a temporary top tube for ladies bike. The top tube on the bike in question doesn't seem that low so I might get away without the bar.
What would the effects of not using a bar? I've read that these bars are necessary for ladies bikes, but why if all it means is the bike sits more level? Will the rack be unstable? Will it mean other bikes won't fit on the rack? etc etc