Saturday, July 12, 2025

Brompton P Line: Stock Condition in Emerald Lacquer

It has been a year (literally) since I got the Brompton P Line, and now I am finally getting around to writing about it. The pictures were taken long ago when I got the bike, showing it in the stock condition.

I had a Brompton M6R some time ago, and that bike was mainly used to carry my kid around in the Bobike child seat upfront. When my child outgrew the child seat, I found myself using the Brompton a lot less. Therefore I sold it away as I had many other bikes to ride.

Let's check out this Brompton P Line and see the main differences and improvements compared to my previous Brompton M6R!

Let's start with a full bike view! Still the classic Brompton silhouette which is super recognizable.

There is no mistaking a Brompton fold, as it is super compact.

Notice that there is no rear rack? Will elaborate more on that later.

Large sticker on the top tube, which I removed after just a short while.


This is the S Bar spec, with  flat handlebar instead of the taller M or H handlebar type.


The bike comes with the front carrier block, which is great! Made of plastic but still more durable than many aluminium ones.

Can be used to carry a front carrier bag, with a max load of 10 kg.

Rear reflector is included as well, which I will remove.

All unnecessary accessories removed, since I don't need them.

Front and rear reflectors, plus front carrier block, weighs 177 grams.

Stock Brompton P Line (S bar, no rear rack and accessories) weighs 9.7 kg, which is a lot lighter than the 12.3 kg of the Brompton M6R.

One important reason why I decided to get the Brompton P Line is because of the gorgeous paint scheme! This Emerald Lacquer colour looks best under sunlight, where the layering effect becomes more pronounced. Check out the pictures below to see what I mean!

Without a rear rack, the bike rests on the 2 roller wheels on the rear triangle, and a tiny wheel on the rear mudguard.

On an S Bar Brompton, the handlepost/stem is taller than that used on the M or H bar.

Another full bike view, this time under sunlight and without accessories.

I chose an S Bar spec because I wanted the handlebar to be lower for a more sporty riding posture.

The old threaded headset design is still being using on the P Line. But at least the hardware is black which looks better when matched to the Emerald green colour.

Love the paint work! The layered paint can be seen when changing the angle of the light.

The visual effect of this lacquer paint is complex, and it not achieved simply by using metallic paint.

Glossy top coat over the Emerald green paint.

The brazed joints have a different colour from the rest of the metal, which gives it a really interesting look.

The Brompton logo is a clear decal pasted over the paint.

Alright just one more picture showing how good the Emerald Lacquer paint work looks.

Taking some measurements of the Brompton P Line.

Folded length with stock saddle is 58 cm.

Folded height with stock saddle is 60 cm.

The reason why I am measuring the folded size with the stock saddle is because I plan to change the saddle later. Since the saddle design directly affects the folded size, I would like to know how a change of saddle affects it.

Saturday, March 29, 2025

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.


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.


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.