With currently having a small 3 door hatchback car, transporting the bike with kit all the time can be challenging. Recently I gave the issue some thought and came up with buying a pair of low range Shimano Hubs and fitting an old cassette to the rear, and using them whilst the wheels are out of the bike.
The idea being that it protects the frame which can be vulnerable without the wheels, and keep the chain tension as it would be the wheels fitted, which also protects the frame from when the chain is slack. The wheels can also be left in the protective bags when arriving home rather than taking them in and out of both the bag and bike.
This ‘transport hub’ method has also created a bit more space at home which can be of the essence without a garage. Using these for the last week I have not yet come across any problems.