As you got an engineering background, you should be able to calculate the propertys of the tubes.
There are usually no data sheets with mechanical propertys available for cured composites parts. But you can usually assume the carbon to be ht-type and the resin to be at least standard epoxy. For products like tubes you can also assume the fibre content to be about 60%.
There are basically two types (plus filament winding, if you want custom taylored tubes) of commercially  available cf tubes. Pultruded tubes consist of fibres, wich are all parallel to the tube axis. I would not recommend those for your project, as they are not very damage resistant.
Roll wrapped tubes consist of 50% of the fibres parallel to the tube axis, and 50% fibres at 90% (usually. You may contact the manufacturer for detailed information).
With this information, the tube dimensions and your background, you should be able to calculate the flex of the tubes quite easily.

Hi
I am looking to build a trike unit for a microlight aircraft as in the photo.
but using CF tubes in place of the aluminium tubes.
Some tubes needs to be rigid with good tensile and compressive strength but with little or no flexibility.
The pair of undercarriage legs, 1 meter each, need to flex about 3 to 4 inches when landing.
Total weight including pilot is 170 kg.
Recommendations please on the type of CF tubes by Easy Composites.
Also is there a website or calculator to figure out how much a particular type of tube will flex for a given load?
Thanks!