Why can’t you just put the bike upside down, with the bars tie
Wrapped to roof bar, with foam in between. Then just secure seat to other bar.

You could do.

Please let us know how you get on.

I have been doing this for years with my Orange 5, and several other bikes. Double sided velcro from Halfords is your friend. Have pics of my set up if you wish.

Pics would be ace.
It’s my old, old bike, for a little morning blast around woolacombe.
So it’s light, rigid, I recon it’ll be okay.

Yup but I used zip ties

If you want cheapness i’ve carted around bikes before strapped to a set of kayak uprights. £20 and job done, never had a problem.

I’d quite happily invert them on the roof like you say if I could get the handlebars in front of the roof bars and the stem on top, a bit of pipe lagging on the roof bars would help.

I have now seen the light though – it’s a lot easier with a pair of thule 591’s on the roof…

Well it got me to Woolacombe nah bother.