Fnhon DB11: Frame and Fork

The time has come to build a new bike! For the year 2019, the major project was the Bike Friday Haul-A-Day, which is a really versatile cargo bike that I use to bring my kid out for rides. In the year 2020, I will start with a new folding bike project to replace my Dahon MuEX.

Why the need or desire to change the Dahon MuEX? It has been a very good folding bike, which has been customized to be a lightweight, high specification folding bike that rides really well. However, after a ride in the rain, that changed.

With V-brakes, the ride in the rain caused the rims to become really dirty with the residue from the brake pads. This is unavoidable, as long as you are using rim brakes (V brakes or caliper brakes) in the rain. I was so annoyed as I spent more time cleaning up the bike than the actual duration of the ride itself.

This can be fixed by avoiding rim brakes, which will cause brake pads to literally disintegrate in the rain. The brakes don't work so well in the rain, plus they mak…

GRX Rear Derailleur: RD-RX815 vs RD-RX817

For the new GRX groupset, there are a total of 4 derailleurs, as shown in the picture below. There are 2 mechanical rear derailleurs and 2 Di2 (electronic shifting) rear derailleurs.

The 4 types of GRX rear derailleurs available.
I am using the GRX RD-RX815 Di2 rear derailleur on my Canyon Endurace for gravel riding, and you can read all about it here. Let me just explain briefly what are the differences between these rear derailleurs.

There is a 1x11 and 2x11 speed spec. The 1x11 speed spec has a shorter cage, and a greater slant angle, in order to shift across the wide ratio cassette (up to 42T sprocket). The 1x11 speed spec cannot be used for front double systems, as the chain capacity is insufficient. This 1x11 speed spec is very similar to the MTB version of Di2 rear derailleur (such as Deore XT RD-M8050), as it is used for wide ratio MTB cassettes.

On the other hand, the 2x11 speed spec is quite similar to road rear derailleurs, like the Ultegra RD-R8050. It has a longer cage to cat…

Polygon Cozmic CX3.0: Shimano XTR M9100 1x12 Speed Drivetrain

I have been trying out different 12 speed groupsets on my Polygon Cozmic CX3.0 MTB, just to compare and feel the differences between them.

The S-Ride 1x12 speed was the first one to be tested, as it was the only upgrade available at that time (August 2018), because SRAM NX Eagle was not available yet. After that, the SRAM NX Eagle 1x12 speed upgrade kit was tested.

Finally we move on to the XTR 1x12 speed setup, which should work better than the other two 12 speed groupsets as it is the top of the range MTB groupset from Shimano. Let's try it out and see how it goes.

XTR RD-M9100 12 speed rear derailleur
There is no longer an extra adapter on the rear derailleur, like other Shadow type rear derailleurs.
Clutch mechanism, with the lever to turn it on and off.
Cable fixing bolt at the inner link of the rear derailleur.
View of the cage set. The guide pulley has a big offset from the rotation axle of the cage set, so that it can reach the larger sprockets of the cassette.
The 51T marking on …