Bicycle Tutor

Hi forum.
I'm new on here but have a question for you all...
I'm after buying two bike racks to go on my Ford Focus.
I have the right roof rack and am looking at buying 2 of the Thule 530 FreeRide.
In the specifications it mentions the following:

Q. Will the FreeRide be suitable for my bike?
A. The FreeRide is designed to fit all sizes and styles of bikes with down tubes ranging from 22mm to 70mm and oval tube dimension of 65mm x 80mm. The wheel straps are adjustable for all sizes of wheels.

I have an old Scott Purgatory that has a down tube that changes shape, from a vertical oval at the top to a horizontal oval at the bottom and an okd Ridgeback Mountain Sport with a round tube.

Maybe a silly question to you all but do I just measure around the tubes? The measurements seem to be far greater than the specifications mentioned.

What do you think?
Cheers, Mcpee

Yes start with measuring the tubes. There are bike racks designed to hold 2,3, and 4 bicycles at one time. Just take your time and asked the sales person for exact advice before purchasing. If you are getting it at your Local Bike shop then they should be able to get you fixed up.