I'm not sure this belongs on a folding bike forum, but here goes .....
I've been wanting to transport a workout bike in the trunk of my Porsche vs using a trunk mounted rack, so this solution is the simplest I could come up with.
I purchased a sacrificial lamb .... Specialized Rock Hopper for $30.00, used my high-tech hacksaw to cut through the top and downtubes, and made sleeves from 1 3/8" 6061-T6 aluminum tubing. Total cost to convert the Rock Hopper to take-apart duty was about $5.00. Forte Slick City ST tires (26 X 1.25) were another $10.00 each at Performance.
I've ridden the bike well over 200 miles so far, and it's plenty rigid for the steep climbing / descending I do on the paved Rocky Mountain roads I normally ride. I'm planning to make a 3 piece take-apart handlebar and possibly add cable break connectors.
Below are a few pics I took today of the bike before, during, and after loading into the front and rear trunks of the car.
Simple is as simple does ..... Tom
After unbolting the SS machine screws / lock nuts, the sleeves slide forward to separate the frame sections.
Everything in this pic will be loaded into the Porsche. I roller ski and bike on Mondays and Friday's and with the exception of the panniers, this is the gear I use.
Take-apart and assembly take about 5 minutes each. The rack is optional.
The folded bike frame and cycling gear fit into the rear trunk. A PVC liner with velcro attachment keeps the trunk clean.
26" wheels, roller skis and gear fit into the front trunk. Ski poles fit between seats.
Earlier this year I made a bike rack for the Boxster. I've owned this Cannondale ST 400 for 25 years .
My favorite homebuilt rack setup ... Specialized TriCross Comp and Triumph Sprint