Brompton M6R: Introduction

Time for a new bike! I have owned and modified many bikes, but have never owned or modified a Brompton before. Before this, I never had a need for a Brompton as I have my other Dahon folding bikes if I need a compact fold. Now, I plan to put a child seat on a bicycle, and I have thought about which of my bikes to put the child seat.

I prefer to have the child seat in front of the rider, which means that all the bikes with drop bars are out. This means that the Java Freccia mini velo, Merida Scultura 5000 road bike and Avanti Inc 3 cannot be used. As for the Dahon MuEX or the Dahon Vitesse, only rear placement child seats can be installed on the seatpost, which will add on more weight to the rear of the bike and possibly make it easier to tip over backwards. Also, it will be good to put the child's weight at the front of the bike to balance out the rider's weight, instead of adding more weight to the rear of the bike.

Bobike child seat mounted on Brompton

Then, I came across the Bobike child seat mounted on the Brompton, and I knew that it was the one that I wanted. Problem is, I did not have a Brompton. I considered getting replica Bromptons such as the Cigna or the 3Sixty, but I was not too impressed with the folding which is still not good enough. Besides, I was reminded of the Flamingo bike that I had previously which was a Brompton replica, and it was just not good enough. Instead of having to fix problems here and there from getting a replica bike, I decided to get a real Brompton and also get a chance to study the real thing.

Initially, I had considered getting a 3 speed Brompton, but 6 speed Bromptons are more common. Besides, no harm having more speeds just in case I need to climb up slopes with extra weight from the child.

I also considered getting a second hand Brompton, but since I was totally unfamiliar with a Brompton, I am not sure what to look out for when getting a second hand Brompton. There are many proprietary parts on a Brompton, and replacements can be hard to find or are costly. Therefore, after checking out the bikes at the local distributor, I finally committed to getting a new Brompton M6R.

There was also a choice of getting the pre-2017 models, or the new 2017 models. For me, the main difference was the shifters, where I liked the 2017 shifters just a little bit better. However, the price difference was $500, which is a lot just for different shifters. Therefore I got the pre-2017 models which are less expensive.

Brompton M6R in Lagoon Blue on all frame parts!

Pre-2017 model, with older shifters

3 speed shifter for the Sturmey Archer hub. At least the brake levers are nice.

2 speed shifter for the 2 speed rear derailleur. Foam grips, not so nice.

2 speed shifter is integrated with a bell

Lagoon Blue handlepost for M bar

Front caliper brake with front reflector and front mudguards

16 inch 349 wheels, with 15mm nutted axles, and fitted with Brompton Kevlar tires

Cable routing to enable proper folding with just the right amount of cable slack

Handlepost and frame hinge clamps, with aluminium clamp plates and plastic levers

From the local distributor

Brompton saddle mounted on the unique Brompton saddle clamp that mounts the saddle forward for a compact fold

Stock elastomer suspension with a Firm rating instead of the softer Standard type

12% reduced gearing with 44T front chainring, on an old school square taper crankset

Rear drivetrain and shifting components. Looks rather haphazard with lots of exposed bits.

Indicator chain that controls the 3 speed hub, along with the 2 speed side swing rear derailleur and the chain tensioner

Rear caliper brake. Note that both caliper brakes have cables that route from below instead of from the top.

Rear rack with stock easy wheels for rolling the bike along when folded

Sturmey Archer 3 speed hub, special Brompton Wide Ratio version, paired with 16/13T sprockets for 6 speeds

In parking mode, with just the rear triangle folded under the frame

Square taper bottom bracket, looks like it can be removed with a standard bottom bracket tool

Zefal pump included with the Brompton bike and cradled in its unique mount

Close up look at the 2 speed side swing rear derailleur and the pulleys

Made in London

The chain tensioner takes up the chain slack when the rear triangle is folded to prevent chain drop

Brompton fully folded. Very compact!

About 2cm of clearance between the foam grip and the ground when folded

Weighs 12.3 kg stock, including the Zefal pump

This bike will be mainly used to carry the child when I cycle, so that everyone can ride together. Cutting weight from this bike is not necessary as there is not much point. Reason being that this bike has a heavy steel frame, and so any weight savings from components will be quite insignificant. From my experience, reducing the bike weight from 12 kg to 10 kg does not make a big difference, as it is still relatively heavy. Also, putting a child of 10+ kg onto the bike will negate any weight loss. Lastly, there is no need to carry the bike when folded, as I can roll it along most of the time.

I have already identified a few areas on the bike that can and should be improved, and these upgrades will be made soon. These upgrades will not make the bike any lighter or ride any faster, but are mostly cosmetic and functional upgrades.

Lezyne Lite Drive Pump for Road Bikes

Here is a short review of the Lezyne Lite Drive Pump which was designed for the high pressure tires of road bikes. I was looking for a slim and lightweight pump for the Java Freccia carbon mini velo, and this one seems ideal.

All black pump with a simple pump mount

Hose is stored inside the pump body itself, and can be reversed for Presta or Schrader valves

Full length of the pump when extended with the hose

Comes with a rubber ring to push against the pump handle to prevent rattling noise due to looseness

89 grams without mount

Exactly 100 grams including the mount

This is a lightweight and functional road mini pump that will match well to any bike. With the hose attachment, it makes it easier to position the pump during pumping, and also prevent the valve from being damaged by the pumping action. A good addition to any bike.

Java Freccia Carbon Mini Velo: Part 7 - Dura-Ace 9000 Groupset

The Java Freccia carbon mini velo is almost completed! All that is left to do is to fine tune the adjustments and it is ready to go.

Java Freccia carbon mini velo, built up with Dura-Ace 9000 components

Looks great!

During my test ride, I found that the riding geometry is really low and aggressive, due to the low handlebar height. In fact, after comparison, the handlebar height is even lower than the Merida Scultura 5000 road bike! It is too low for comfort, which is why I decided to flip the stem to make it more comfortable.

Handlebar height on the Java mini velo is even lower than the Merida road bike

Controltech 80mm stem was originally installed with a downward tilt

After flipping the stem to be upward tilting, the geometry is better and almost the same as the Merida road bike

Another view of the full bike with the geometry properly set up

Full bike weight is only 6.7 kg inclusive of pedals!

Full specifications of the bike. I did not use any boutique super lightweight components, all can be found easily. Theoretical weight is equal to actual measured weight. Only 6.3 kg without pedals!

Completed bike spotted in the wild

Using the Ridea brake pad extenders with Ridea brake pads

Same for the rear wheel. Braking power is better than expected.

Java Freccia carbon mini velo project completed!

Yet another bike building project has been completed, and I am very pleased with the results. This mini velo is very lightweight at only 6.3 kg without pedals. Also, it rides really well, despite the short chain stays. Braking power using the Ridea brake pads is actually quite good, and I don't miss the SwissStop brake pads. Shifting performance with the Dura-Ace groupset is of course top class, while the Wheelsport Smart 1.0 451 wheels roll really well.

Despite my initial worries, there has been no creaking sounds from the press fit bottom bracket, while the integrated seatpost clamp has not given me any problems with slippage. Other than the insufficient reach from the road brake calipers and the slightly tricky internal cable routing, there has not been any real issues with the installation.

I have tested it while riding with some road bikes, and this mini velo actually feels just as fast as my Merida road bike! The weight difference is felt most during climbing, where this bike just keeps moving instead of dragging you back like on some heavier bikes. Carrying the bike up the stairs or anywhere is a breeze due to the low weight. It is currently my favourite bike to ride as I have rediscovered the joy and fun of riding a mini velo!

 Riding the Java Freccia mini velo by the sea

Java Freccia Carbon Mini Velo: Part 6 - Almost Completed

In Part 4 of this bike project, I showed that the drivetrain of the bike was already installed. Prior to that, I had to first install the press fit bottom bracket into the frame, before the crankset can be installed.

I have never installed a press fit BB before, so I had to do some research to make sure I do it properly. Also, I have heard of some cases of press fit BB causing creaking sounds during pedaling. Therefore, it was even more important that I do the installation properly to avoid any creaking later on.

As already checked previously, this frame accepts a Shimano type press fit BB. To ensure good performance and low weight, I chose the Dura-Ace grade press fit bottom bracket. Although it is not the smoothest bottom bracket around, the sealing should be good, while it is also relatively cheap and lightweight.

Dura-Ace grade press fit bottom bracket, SM-BB92

Plain looking bottom bracket, with the two press fit diameters at both sides

Press fit bottom bracket cups are made of engineering plastic, PA+GF for strength while also being lightweight

Press fit BB weighs only 55 grams, which is lighter than threaded type BB

Using the proper press fit tool for pressing the bottom bracket cups into the frame. It is very simple, basically a threaded rod with correctly sized plates at both ends to push in the cups.

Done! Greased the contacting surfaces and managed to press in the cups easily and fully.

Installing the press fit bottom bracket was actually quite easy. The resistance felt just right, while the cups were able to enter fully until they were flat against the frame. Hopefully there will be no creaking sound when I ride the bike later on.

After the press fit bottom bracket was installed, the Dura-Ace 9000 crankset was then installed without any issue.

With the drivetrain and brakes installed, the next thing to install would be the controls of the bike, which is the handlebar. Since the handlebar and shifters will be the same as that on the Wheelsport mini velo, I can transplant the whole handlebar setup over without removing the shifters.

The shifter inner cable will be changed, since the old one is already worn out and is also a bit too short. The brake inner cables can be reused. However, all the outer casing will need to be changed as the cable entry point for the shifter cables into the frame is different, while the brake cable routing has been changed from semi outer casing (with external cable stoppers) to full outer casing.

In this case, there is no choice but to remove the bar tape to redo the outer casing coming out from the shifters. No problem, since the bar tape is due for replacement anyway.

Handlebar setup shown as removed from the Wheelsport mini velo, before installing new inner cables and outer casings.

After much work, the handlebar setup is completed! New cabling all done up nicely.

80mm Controltech stem matches nicely with the colours on the FSA K-Force carbon handlebar

Rear shifter cable enters the frame at the downtube for neat internal routing

Rear brake cable enters the top tube from the front, and exits at the rear. Clean internal routing for this frame.

Using the same lightweight Selle Italia SLR Kit Carbonio Flow saddle on the new aero seatpost

Front single drivetrain for this bike. Look at the massive bottom bracket junction for stiffness!

Dura-Ace 9000 crankset!

Full Dura-Ace 9000 1x11 speed drivetrain!

Left side view. Since the bottom bracket bearings are fitted within the frame, this frame can be wider than an equivalent frame with an external threaded bottom bracket.

Using a custom tool to center the handlebar with the front wheel. The idea is to place the jig on the stem and handlebar, while a laser pointer will indicate the centreline of the handlebar, which is where the front tire should be.

Once done, just line up the front wheel with the laser pointer and the handlebar should be perpendicular to the front wheel.

During this alignment, I found that there are a few issues that can affect the accuracy of this laser guided handlebar alignment jig.

1) The placement of the laser pointer within the jig itself will affect the accuracy. If the laser pointer is tilted just a couple of degrees off, it will not be accurate anymore.
2) The laser beam may not exit the laser pointer exactly straight. This can be remedied by rotating the laser manually during calibration.
3) Distance from handlebar to front tire can affect the accuracy, especially if the laser is tilted to one side slightly.

In my case, the jig is for reference only. Final alignment is still based visually and my feeling during riding.

This bike is almost completed! In the next post, the full bike build will be shown, along with the bike weight (it is really lightweight!) and the component specifications.