Fnhon Ultegra Di2 12 Speed: Ultegra R8100 Crankset and new Kickstand

Final post for the Fnhon Ultegra Di2 12 speed folding bike! In the previous post I prepared the Ascent Cirrus Elite carbon wheelset for use on this bike. Due to the change of wheel size from 451 to 406, the gear ratio has been reduced by approximately 10%.

As the gear ratio should be carefully chosen to match the usage and rider's abilities, any significant change in the gear range will affect the suitability of the gearing. The previous gear range was 30 - 92 gear inches, which is ideal for climbing and relatively fast rides on the road.

However, changing the wheel size from 451 to 406 will cause this gear range to decrease to 27 - 84 gear inches, which does not have sufficient top speed for road riding.

Therefore, the easiest solution is to increase the chain ring size to compensate for the smaller wheel size. A Stone 46T narrow wide chain ring was used, and this will be changed to a larger 50T chain ring.

Stone 50T narrow wide chain ring. Weighs 118 grams, which is 20 grams more than the 46T version.

Compatible to Shimano 12 speed chains, and also the Shimano 4 arm road crankset BCD.

Close up look at the narrow wide teeth, for good chain retention. Chamfered teeth to reduce driving noise.

New 50T chain ring installed on the Ultegra R8100 crankarm! Along with my iconic coloured chain ring bolts.

Alongside the left crankarm

Right side crank arm with 50T chain ring weighs 480 grams

Left crank arm with crank arm fixing bolt weighs 195 grams

Total crankset weight is 675 grams, which is decent. This is the same Ultegra R8100 crankset that was on the Focus Paralane. After I disassembled that bike, I reused the components across a few of my other bikes. Now, the Fnhon Ultegra Di2 12 speed bike has a full Ultegra R8100 groupset.

After swapping from 451 to the smaller 406 wheelset, the kickstand does not work so well any more. The kickstand length is important, as it determines how much the bike tilts when parked. It is related to the wheel size, as a larger wheel diameter means that the axle height of the bike is higher.

With smaller 406 wheels and previous kickstand (optimized for 451 wheels), the bike angle is too straight when parked. This causes it to tilt over very easily.

I ordered a shorter kickstand to replace the original kickstand.

Original kickstand for 451 wheels weighs 158 grams

New shorter kickstand for 406 wheels weighs a bit less at 152 grams

With the correct kickstand, the bike leans to the side a bit more, which is what I wanted. Too little or too much tilt makes the bike unstable.

New shorter kickstand also helps to create a bit more clearance with the rear rotor when put up.

There is little space to fit a kickstand between the rear rotor and the rear wheel spokes.

With the new kickstand installed successfully, the modification of the Fnhon Ultegra Di2 12 speed folding bike is completed! Below are the pictures of the bike in its final state (I think). It has evolved a lot over the years, starting from a 11 speed flat handlebar setup with XTR Di2 components, to its current drop bar setup with 12 speed Ultegra Di2.

Ascent Cirrus Elite front wheel with new Panaracer Minits tires and Ashima Ai2 rotor!

5 mm adapter added to push out the rotor, from the Birdy position to the standard position.

Same setup for the rear wheel, but with a smaller 140 mm diameter rotor.

Shimano Ultegra R8100 crank arm, with Stone 50T narrow wide chain ring.

Here is the refreshed drivetrain! Matte grey rims and crank arms give a different look. The rear derailleur has a custom short cage to have more ground and tire clearance.

Full bike view with high profile carbon rims but smaller 406 wheel size.

Previous setup with larger 451 wheels but low profile rims. I like both even though they give off different vibes.

All the components you see here are high end stuff!

Saved 200+ grams with these upgrades. Now the bike weight (excluding pedals and kickstand) is just 9 kg! Just slightly more than the flat handlebar Fnhon DB11 setup.

Extra pictures of the bike out for test rides. Here is the giant pumpkin at Elementum, near Buona Vista.

At the old Bukit Timah Railway Station.

Birdy AXS: Assembly Part 2

Even before I got the Birdy City, I already planned to make major modifications on it. In fact, the modification ideas have already been floating around in my head for quite some time, just that I didn't proceed with it.

For full bike modification projects, I think it is a good idea to test out the bike in its stock condition first, so that you know the baseline performance. Afterwards, when the modifications are complete, the performance can be compared so that you can appreciate the upgrades and improvements.

As planned, many of the drivetrain and components will be moved over from the Fnhon DB12, as the Birdy will be replacing the Fnhon as my go-to folding bike. As such, I won't be sharing the details of the existing components, as the information can be found over at the Fnhon DB12 blog page.

For those components that are new, the details have already been shared in the earlier posts, or you can find the links at the relevant picture captions below.

Let's start with a picture of the completed bike, before zooming into each component for more detailed pictures.

Birdy upgrade complete! The new model is now Birdy AXS 12 Speed.

Birdy AXS: Hubsmith Freehub Construction and XDR Freehub Body

In the previous post, I wrote about how I wanted to transfer the compatible components over from the Fnhon DB12 to the Birdy folding bike. The SRAM AXS groupset will be transferred over, but this is not so straightforward.

The SRAM Force 10-36T 12 speed cassette requires a XDR driver, which is not commonly found on small wheeled bikes. On the custom 451 wheelset by Ascent Bikes, I was lucky the Novatec rear hub has a compatible XDR freehub body which enabled the modification.

On the new Cirrus Elite 406 carbon wheelset, I checked to make sure that the Hubsmith rear hub has a compatible XDR driver, so as to use it with a SRAM cassette. The default freehub body is the Shimano HG spline design, which may be useful one day, so I will keep it around.

XDR freehub body for the Hubsmith rear hub. This is an additional part which I purchased together with the Cirrus Elite wheelset.

Birdy AXS: Ascent Cirrus Elite Carbon Wheelset (20" 406)

Finally, after thoroughly studying the Birdy City in its stock configuration, and disassembling the frameset to study the individual frame parts, I can now move on to share about the new components!

Prior to getting the Birdy City, I already had a rough idea of what I wanted to modify on the Birdy. Most of the components are decent, and would be good enough for casual riding. However, since I wanted to use the Birdy to replace my existing Fnhon DB12 folding bike, I plan to transfer most the compatible components such as the SRAM AXS drivetrain over to the Birdy.

The main major component that cannot be transferred over would be the custom 451 wheelset on the Fnhon DB12. For a start, the 451 wheel size is too big to fit on the Birdy, as it can only accept a maximum wheel size of 406, and that is with slim tires.

Next, the Birdy requires a special front hub, with inward offset hub flanges and rotor mounting. Therefore, a new wheelset is needed for the Birdy, due to the special hub design.

Whenever I want to get a new wheelset, I will always consider getting one from Ascent Bikes. I have actually gotten quite a few wheelsets from them, with some of them custom built.

1) Extra strong 20" 406 wheels custom built for the Bike Friday Haul-A-Day cargo bike.

2) Low profile lightweight 20" 451 wheels custom built for the Fnhon DB12 folding bike.

3) Zenith Elite 700C road wheelset with a quiet rear hub for the Cervelo Aspero, and later the Focus Paralane.

Therefore, I decided to get a high end carbon wheelset from Ascent Bikes for the Birdy. The model is Cirrus Elite, which comes in either 406 or 451 rim sizes, and various other hubs. In this case mine is a pretty standard configuration for Birdy bikes.

Birdy Wheelset Specifications:

Birdy compatible Hubsmith front hub and rear hub.

Quick release axles.

100 mm front OLD, 135 mm rear OLD.

Shimano HG spline on the rear hub.

Disc brake mounting (only 6 bolt is available, not Centerlock).

50 mm tall 406 carbon rims with black bladed spokes and spoke nipples.

3M reflective decals (Darklight).

The wheelset is actually hand built in Singapore, with some of the components flown in from overseas. So you could actually customize it if you wanted to, subject to part compatibility and availability. I did not have to wait long for the wheelset, it took just slightly over a week.

New wheelset fresh from Ascent Bikes!

Dura-Ace C50 R9270 vs Ascent Zenith Elite Wheelset

Here is a comparison between two carbon road wheelsets with similar specifications. Both are 700C road wheelsets, with 50 mm rim height. The wheelset weight is is also similar as you will see below.

In this comparison, it is mainly about the physical characteristics of each of the wheelset. Let's check out the new Dura-Ace C50 R9270 wheelset, versus the previous Ascent Zenith Elite wheelset. For the detailed analysis of each wheelset, check out the individual posts via the links.

Dura-Ace C50 R9270 vs Ascent Zenith Elite wheelset! Different spoke lacing pattern as seen here.

Fnhon DB12: Ascent Revolution BB

While modifying the Fnhon folding bike to a 12 speed drivetrain, I took the chance to swap the bottom bracket as well. Not that the existing SM-BBR60 bottom bracket had any problems, but because I wanted to try the new bottom bracket by Ascent Bikes.

Special packaging! Very premium looking design.

This is for Shimano type of Hollowtech cranksets, which uses a 24 mm spindle diameter, and 68 mm wide, English threaded bottom bracket shells.

Full aluminium construction, where the left and right adapters are mated to each other for better concentricity control. It comes with a 1 mm spindle spacer in case you need it.

Designed in Singapore! The center cover extends out from one side of the adapter, instead of being a separate plastic piece like on Shimano bottom brackets.

Bearing dust cap on the side of the bottom bracket.

The left and right adapters are mated together during assembly, which helps to align the left and right side.

Since the threads on the left and right side of the frame are machined separately, there will be some tilt or concentricity error between the left and right side. Also, the faces of the bottom bracket shell may not be completely parallel to each other, causing the adapters to tilt slightly once fully tightened.

If the left and right adapters are not completely concentric to each other, there will be some imbalance and resistance to rotation, once the crank spindle is inserted. If the deviation is big, there will be extra friction and possibly lower bearing life.

This Ascent Revolution Bottom Bracket is designed to solve this issue, by using an extended center shaft to join the left and right side adapters together. This ensures that the concentricity error, if any, will be mitigated by the shaft alignment. However, in actual practice, if the deviation is so much that the shaft is needed to align them, it might not even be possible to assemble the bottom bracket, since the two halves will not be able to slot into each other.

Once fully tightened, I am not sure if the adapter position will be determined by the mating of this shaft, or will it be determined by the outside faces of the bottom bracket shell. I think it will help to a certain extent, especially if the outside face of the bottom bracket shell is poorly faced, like I encountered on the Brompton.

Bottom bracket weighs 111 grams, a noticeable increase over the BBR60 bottom bracket which weighs 76 grams.

During installation, the non-drive side bearing dust cap got pushed out by the crank spindle. Not a big problem as it can just be pushed back in.

New bottom bracket installed! No spacers needed under the bottom bracket, as the chain line is OK.

The benefit of this bottom bracket is smoother crank rotation, due to better bearing alignment and smoother bearings. I did find that the rotation is smoother than the BBR60 bottom bracket, but it is not buttery smooth like ceramic bearings.

Video showing the Ascent Revolution bottom bracket in action.

The BBR60 bottom bracket was only able to spin about 1-2 rounds in stock condition, so this Ascent Revolution bottom bracket is an improvement as it can spin 6 rounds.

I would say it is an upgrade over the BBR60 bottom bracket, due to the improved rigidity and also smoother rotation. However, it is not a day and night difference, like if I changed to a super high end ceramic bottom bracket where the cranks just keep spinning for more than 10 rounds.

Cervelo Aspero: Front Single Road and Gravel Drivetrain

From the first set up of the Cervelo Aspero, where I first used a 2x11 speed drivetrain for road and gravel riding, I have now changed to a dedicated 1x11 speed gravel drivetrain.

The Aspero is now a dedicated gravel bike, which is why I have changed some of the components to make it more suitable for gravel riding, instead of striking a balance previously between road and gravel usage.

Other than the drivetrain, I have also changed to the GRX Di2 shifters, which has ergonomics that are very well suited for gravel riding. The default wheelset is also the excellent Hunt 650B carbon wheelset, with WTB Venture 47 tires.

That said, if I want to, I can still swap it to a road wheelset, if I ever want to ride fast on the road with this Cervelo Aspero. This is because the Ascent Bikes Zenith Elite wheelset is using the Sunrace RX1 11-36T cassette, which is relatively similar in size to the SLX CS-M7000 11-42T cassette on the Hunt wheelset. Previously I have swapped between the 11-30T cassette and the 11-36T cassette, without adjusting the rear derailleur at all, so I think swapping between the 11-36T and 11-42T cassette is possible.

Default gravel wheelset on the left (Hunt 650B + Venture 47 tires + 11-42T cassette) and the road wheelset on the right (Zenith Elite + GP5000 tires + 11-36T cassette).

From the picture above, you can see that the external wheel diameters are similar. This post shows the size difference in detail. The Zenith Elite carbon wheelset is currently being used on the Focus Paralane, as my all-weather commuting road bike.

Road wheelset with 11-36T cassette installed on the Cervelo Aspero.

Distance between the largest 36T sprocket and the guide pulley is a little further, since the rear derailleur is set for a 42T large sprocket. However, shifting is still OK.

Looks good as a road bike too!

With a carbon road wheelset, this Aspero can be converted into a pretty fast bike as well. It is only limited by the small 38T chain ring, which is good for gravel riding but rather small for road riding.

Full specifications of the Cervelo Aspero in road setup. Weighs about 7.5 kg without pedals.

As for the gravel setup, it will definitely be heavier, due to the heavier wheelset and larger cassette.

Installed the XTR RT-MT900 rotors onto the Hunt wheelset.

For a comparison of MT900 vs MT800 rotors, check out this article.

Full gravel setup

I think this setup is perfect for gravel riding!

The gravel setup weighs about 8.1 kg without pedals, with the additional 600 grams of weight coming from the wheelset.

Although it is possible for this Aspero to be set up as a road bike as shown above, it is not so likely that I will use it for road riding. I would just take the Focus Paralane instead, as it has more road specific components, such as a slightly larger chain ring and road shifters.

In any case, this Aspero is so versatile that it can be setup as a full road bike or full gravel bike, or anything in between.

Focus Paralane: Road Bike Setup

Upon completing my Focus Paralane all-weather road bike, I felt like there were still some areas which can be optimized. Now that this is my fastest bike, it is my first choice bike for commuting, regardless of weather.

While looking at my Focus Paralane and Cervelo Aspero side by side, I realized that I can swap some of the components around to optimize either one or both bikes.

After I had built this Focus Paralane as my road bike, I realized that I didn't need the front double gearing on my Aspero for road riding. Therefore, I will be converting the Aspero to a front single drivetrain, and make it optimized for gravel riding instead. I will no longer use it to double up as both a road bike and a gravel bike, after my failed trial of having a wide range cassette with a front double Di2 system.

Focus Paralane: For road cycling (either wet or dry), with close gear steps

Cervelo Aspero: For gravel riding, wider gear steps are acceptable

One of the first component that I identified was the front single chain ring. I found that it would be preferable for me to use the relatively small 38T Wolf Tooth chain ring on the gravel bike instead, and get a slightly larger chain ring for the Focus Paralane road bike. After all, I don't need high gearing when riding on gravel with wide gravel tires.

As first tested on the Fnhon Gust, the Stone branded narrow wide chain rings from Taobao work well, and are half the price of Wolf Tooth chain rings. They also make a wide range of chain rings to fit different cranksets, and also different number of teeth.

Stone narrow wide chain ring

"Chocking" hazard, "prodoct" contains small parts. With this kind of spelling, the last 3 words are not necessary to know the place of manufacture.

40T chain ring, which is suitable for my riding style and speed.

Machined narrow wide teeth for secure chain retention.

Weighs 78 grams for a 40T chain ring, which is quite average.

Other than the chain ring, I decided to move the Dura-Ace R9100 crankset over from the Aspero to this Paralane. I think it is not ideal to use the nice-looking Dura-Ace crankset for off-road bashing on the Aspero. Let's put the Ultegra R8000 crankset on the gravel bike instead.

Besides, if I am going to be riding the Paralane frequently for commuting, I might as well use the best components that I have. My concept is that my best components should be used on the bike that I ride most frequently.

New 40T Stone chain ring on the Dura-Ace R9100 crankset. In my signature Infinity Stones colour scheme as seen on the Dahon MuSP, Fnhon DB11, and Cervelo Aspero.

Drivetrain completed, with new crankset and chain ring.

Using the Dura-Ace R9150 Di2 rear derailleur and Ultegra R8000 11-32T cassette.

With this 40T chain ring, my gearing on the Focus Paralane is thus 34 - 98 gear inches. Slightly higher than the previous gearing of 32 - 93 gear inches. Should be good for road riding as calculated.

The road hydraulic shifters were also changed from Ultegra to Dura-Ace. I basically swapped most of the groupset from the Cervelo Aspero over to the Focus Paralane. As to what shifters the Aspero is now using, that is a story for another day.

Using the new TL-BR001/002/003 bleeding tool kit from Shimano. The adapter is now integrated with the cup.

The syringe is also much better, with a screw-on connection at one end, a well-fitting nozzle at the other end, and a clip in the middle to stop fluid flow.

Dura-Ace ST-R9179 road hydraulic Di2 shifters, first used on the Canyon Endurace.

A fresh set of bar tape always makes the bike feel new again!

Since my target is to optimize the Focus Paralane for road riding, I might as well go all out and put on the best road wheelset that I have. Although I already have the pretty decent RS770 wheelset, I do have an even better road wheelset, the Ascent Bikes Zenith Elite wheelset.

This high profile carbon wheelset was used in rotation on the Cervelo Aspero, to convert it between a road bike and a gravel bike. However, since the Aspero will now be used primarily as a gravel bike, I can use this Zenith Elite carbon wheelset full time on the Focus Paralane. This interchangeability is possible because all these disc brake wheelsets are using 12x100 and 12x142 mm E-thru hubs.

High profile carbon wheelset

Looks awesome in the sun!

Now it looks different, with a high profile carbon wheelset!

This carbon wheelset will be undergoing a pretty harsh test as it will be used in wet weather as well.

Usually carbon wheelsets are not used for commuting, as they are deemed to be "too good" for regular commuting. However, I want to commute fast, and I want the ride to be just like a proper road bike. Therefore I don't mind using a carbon wheelset on this Focus Paralane. Otherwise the wheelset will just be hanging on the wall instead...

Testing the new gearing by riding to the top of Jurong Hill

Lowest gear of front 40T and rear 32T is just enough for riding up the short but steep slope at Jurong Hill.

Mudguards are not that obvious, after I changed to the high profile carbon wheelset.

Also tested the gearing by riding up to Mount Faber.

It was tough for me to climb the longer slope at Mount Faber, as my low gear is not low enough. I needed one more lower gear which I didn't have.

Updated bike specifications, with the conversion to full road bike setup. Now only 7 kg without pedals or mudguards, which is on par with most high end road bikes.

I'm really pleased with the full road bike conversion, especially with the high profile Zenith Elite carbon wheelset. It is more aerodynamic, and yet also lighter than the RS770 wheelset.

The weight of 7 kg (without pedals or mudguards) is on par with most other high end disc brake road bikes. This is a far cry from my first attempt at making a drop bar commuting bike with the Avanti Inc 3. That setup weighed 10.9 kg without pedals or mudguards, a whole 3.9 kg and 55% heavier than this Focus Paralane.