Folding Bike 3-way Component Swap

This was a relatively complex bike modification project, as it involved 3 different bikes with many different components. Main reason for all these swapping is to upgrade to the latest components, and sell away the older and more basic components.

Flowchart showing the bikes before the component swap.

After the component swap

In the pictures above, you can see that I removed the stock Sora 1x9 speed drivetrain from the Birdy City. The Birdy will then be upgraded to a SRAM AXS 12 speed setup, with the components coming from the Fnhon DB12.

I kept the Fnhon frameset, as it is a nice frameset with disc brakes. The Fnhon frameset is then upgraded with the latest Ultegra Di2 12 speed drivetrain, to make it a drop bar folding bike with disc brakes.

Meanwhile, the Dahon MuSP's existing Ultegra Di2 11 speed drivetrain is removed, and replaced with the Sora 1x9 speed drivetrain taken from the stock Birdy City.

Finally, the Ultegra Di2 11 speed drivetrain is sold away, as it is considered an older groupset, since the new 12 speed version is better is nearly every way.

The Dahon MuSP is reborn as a basic folding bike with Sora 1x9 speed mechanical drivetrain. This bike is now considered surplus to me, since I already have the Birdy AXS 12 speed flat handlebar folding bike, and the Fnhon Ultegra Di2 12 speed drop bar folding bike. Therefore, the Dahon MuSP was sold away after all these modifications.

Birdy upgraded from the stock Sora 1x9 speed to SRAM AXS 12 speed

https://handsonbike.blogspot.com/p/birdy-axs-12-speed.html

Fnhon modified from AXS flat handlebar to Ultegra Di2 drop bar, also 12 speed.

https://handsonbike.blogspot.com/p/fnhon-ultegra-di2-12-speed.html

Dahon MuSP modified from Ultegra Di2 11 speed drop bar to Sora 9 speed flat handlebar.

https://handsonbike.blogspot.com/p/dahon-musp.html

In summary, with all these swaps, I upgraded my drop bar folding bike from Ultegra Di2 11 speed with caliper brakes, to the latest Ultegra Di2 12 speed with hydraulic disc brakes.

Flat handlebar folding bike changes from the Fnhon to the Birdy, keeping the same AXS 12 speed drivetrain, but with the addition of the Birdy suspension for comfort. Weight increases by about 300 grams, from 9.4 to 9.7 kg inclusive of pedals and kickstand.