Dahon MuSP: Sora 1x9 Speed Flat Handlebar

When I got the Birdy City folding bike, I created this plan to transfer components across these few bikes.

1) Dahon MuSP with Ultegra Di2 11 Speed

2) Fnhon DB12 with SRAM AXS 12 Speed

3) Birdy City with Sora 9 Speed

This is a good chance to refresh the components on the bike, and upgrade to something more modern. 

Key objectives:

1) Sell away the old Dahon MuSP frame with rim brakes.

2) Sell away the older 11 speed Ultegra Di2 groupset.

3) Upgrade the existing drop bar folding bike (Dahon MuSP) to Ultegra Di2 12 speed.

4) Upgrade the Birdy City to a high end folding bike with premium components.

With some planning, lots of time and effort, plus some cost, I managed to complete this 3 bike swap successfully!

Overall plan to modify these 3 bikes. The SRAM AXS components have already been transferred onto the Birdy folding bike earlier.

With the Birdy City stripped of its stock 1x9 speed Sora components, these Sora components can then be installed onto the Dahon MuSP frameset. In this post, I will focus on the specifications of the Dahon MuSP, which has a freshly installed 1x9 speed Sora groupset.

Sub-project, to convert the Dahon MuSP from a high performance 1x11 speed Ultegra Di2 groupset to a mid-range 1x9 speed Sora groupset.

With some planning, I was able to reuse many of the new components from the Birdy City folding bike. These are basically brand new components, taken off the stock Birdy City and installed onto the Dahon MuSP frameset. If you recall, I got the Dahon MuSP as a frameset instead of a full bike, so it is no problem for me to disassemble the bike again.

Check out the full specifications of the reborn Dahon MuSP below!

Full bike picture of the reborn Dahon MuSP

Original Dahon frame, with a rare blue coloured headset.

Super high gloss frame, with smooth welds all around, such as the head tube junction shown here.

Only premium frames have an internal frame clamp design. Smooth welds at the joints.

Smooth welds along the curved frame and seat tube junction as well. Blue seat post clamp is pretty uncommon as well.

Here is the drivetrain! This includes the rare item, the blue Wheelsport Smart 451 wheelset for rim brakes.

Sora 9 speed rear derailleur, cassette and chain, all from the stock Birdy City. 

Note the little blue cable end cap as well!

Stock Birdy crankset and bottom bracket from the Birdy City, with 52T chain ring and chain guard. 

Folding pedals are from my spare parts collection.

Including these Wheelsport wheels on the bike is a good deal! Even the tires are high quality Panaracer Minits Lite.

Best of all, the Ultegra R8000 road caliper brakes remain on the Dahon MuSP!

Ultegra R8000 road caliper brakes front and rear, rim brakes doesn't get much better than this.

The reason I am willing to include the high quality Wheelsport wheelset and Ultegra R8000 brakes with the Dahon MuSP, is because I am transitioning all my bikes away from rim brakes and onto disc brakes. I can't use these components on any of my other disc brakes bikes, while it will be difficult to dismantle and sell them separately. I would just rather make it a sweet deal for the lucky buyer who gets to use these high quality components. From my experience, it is much easier to sell a full bike than to sell the components piece by piece.

Converting the Dahon MuSP from a drop bar back to a flat bar setup. Also changed to a spare taller one-piece handlepost which was from the previous United Trifold project.

Lightweight and rigid 2-bolt handlepost clamp, and a Toseek carbon flat handlebar. Good stuff here.

Sora brake levers, shifter and grips transferred over from the stock Birdy City.

Even the Birdy saddle is transferred over, while the Litepro seat post remains.

Dahon MuSP 1x9 speed shown as folded. As compact as it gets for a bifold folding bike.

Reborn as a freshly furnished bike, completely cleaned up and well adjusted. Likely to work better than most stock bikes.

Folding the handlebar inwards makes the folded package much narrower, unfortunately this is only possible with flat handlebars and not drop bars.

Final weight of the reborn Dahon MuSP 1x9 speed is 9.7 kg including of pedals, which is a pretty good weight!

Of course, building up this Dahon MuSP again is not as easy as it looks in the pictures above. I had to redo all the inner cables and outer casing, as well as disassemble and assemble all the components.

Here is the masterplan! The Birdy and Dahon MuSP have been completed and shown, while the Fnhon DB12 with Ultegra Di2 12 Speed will be shown later.

With this 3 bike swap, I was able to achieve all the objectives, which is basically a refresh of my bike collection from 11 speed to 12 speed, and from rim brakes to disc brakes.

Key objectives:

1) Sell away the old Dahon MuSP frame with rim brakes.

2) Sell away the older 11 speed Ultegra Di2 groupset.

3) Upgrade the existing drop bar folding bike (Dahon MuSP) to Ultegra Di2 12 speed.

4) Upgrade the Birdy City to a high end folding bike with premium components.