Fnhon DB12: SRAM Force AXS 12 Speed Cassette and Chain

My 1x11 speed Fnhon DB11 was completed at the end of 2019, and I have been happily riding it for about 1.5 years. There was basically nothing much that I want to upgrade, since it is already using top level components, such as XTR brake levers and brake calipers, and Dura-Ace/Ultegra Di2 shifting components. I purposely chose an aluminum wheelset as I don't like high profile carbon rims on small wheels due to aesthetic reasons. 

Therefore, this following modification is mainly down to itchy backside syndrome, as there is no real need to modify, nor can it really be considered a substantial upgrade.

I have been wanted to try the SRAM AXS system since it was launched, mainly due to the unique shifter that looks and works differently from others. However, it is difficult for me to use it, as it means I need to change the whole drivetrain ecosystem over to SRAM 12 speed.

SRAM AXS shifter with the unique ergonomics

At the start, it was only the MTB 12 speed system that was available, with a super wide range 10-50T cassette that is only suitable for MTB. Since I had already sold off my MTB due to very very limited use, I don't have a bike that can actually use this 12 speed system.

Alternatively, I could have used the road 12 speed AXS eTap system, but I didn't like the idea of using DOT fluid in my hydraulic brakes, plus I preferred the ergonomics of the Di2 hydraulic shifters over the SRAM road hydraulic shifters.

Then, I came across this SRAM Force 10-36T 12 speed cassette, which looks interesting as it is small enough to be used on small wheeled bikes, which gave me this wild idea to install a 1x12 speed AXS system on this Fnhon folding bike.

First I had to do some preliminary study to make sure that all the 12 speed components are compatible with the bike. The cool thing is that I can use a AXS shifter (for MTB flat handlebar) with a AXS rear derailleur (road short cage type).

AXS Shifter - Fits on standard flat handlebar

AXS Rear Derailleur - To use the road/gravel type, with a shorter cage than MTB spec

AXS 12 speed Cassette - Needs XDR freehub body on the rear hub

AXS 12 speed Chain - Need compatible front chain ring for AXS chain

Spoiler: Yes it all works, as you will be able to see from subsequent posts. The tricky part was converting the rear hub from the existing 11 speed road (Shimano spline) to the SRAM XDR freehub body, which will be shown in a later post.

Before that, let's take a close look at the SRAM 12 speed cassette and chain.

Here is the SRAM Force XG-1270 12 speed cassette

Using my home workshop with some Park Tool items!

This is the Force 10-36T spec, with some pinned sprockets instead of a one-piece machined design on the SRAM RED version.

Only the largest sprocket is black in colour, unlike the older version where the whole cassette is black in colour.

First time I will be installing a SRAM XD or XDR cassette. Still uses the same lock ring tool though.

This 12 speed cassette only fits on XDR freehub bodies.

Only the largest sprocket has splines that engage with the XDR freehub body, plus a screw thread engagement on the inside, similar to that of a freewheel.

Lots of small rivets between the multiple sprockets, transferring the load to each other instead of directly to the freehub splines.

Sprocket sizes are: 10,11,12,13,15,17,19,21,24,28,32,36.

I like the sprocket combinations, as it maximizes the range without making the steps between gears too big. In fact, it is exactly the same as the Sunrace RX1 11-36T 11 speed cassette, just with an additional 10T sprocket at the top.

There is this light grey rubbery layer between the 32T and 36T sprocket. It seems that this is to dampen the driving sound during riding.

The black "spacers" you see between the smaller sprockets are actually rubber rings to dampen the driving sound. The smaller sprockets are actually machined as one piece, so there is no need for spacers between them.

This 12 speed 10-36T cassette weighs just 310 grams, which is lightweight for the size.

I was impressed with the low weight of this Force cassette, as it is lighter than the Ultegra HG800 11-34T 11 speed cassette, which is 337 grams, despite having a wider range and one more gear.

A 12 speed AXS chain is also required, as this AXS system is not compatible with other chains, due to larger rollers being used on the SRAM AXS 12 speed chains. There will be a separate chain comparison post later on.

SRAM Force AXS 12 speed chain

Made in Portugal!

These 12 speed AXS chains have a distinctive look, with the Flat Top design to add some strength, to compensate for the thin side plates.

Weighs 299 grams before cutting, inclusive of the box weight.

It is the first time I am using the XDR freehub body, in order to use this 12 speed cassette. It is new to me, as my previous 12 speed cassettes were using a standard freehub spline, with a top sprocket size of 11T instead of 10T. In the next post I will show how I changed the freehub body to the XDR type.