Modifications to Flamingo London NX7: Crankset, Chainguard, Pedals & 1 Roller Wheel

Some upgrades to my humble Flamingo! Most of the time, an upgrade to the Flamingo is done not because I want to go faster, but just because it can be done!

I have recently upgraded the crankset for the Flamingo, from the stock Driveline 48T crankset to a new Shimano Sora 50T crankset. The inner 34T chainring was removed as it is not needed.

New Shimano Sora 50/34T crankset!

The stock chainguard cannot be used as the BCD of the crankset is different. The stock Driveline crankset has a 130mm BCD, but the Sora crankset has a compact BCD of 110mm. This is why I could not just install the same chainguard.

Without the chainguard, there isn't actually much of a problem. The chain does not drop off as it does not need to shift across a cassette at the back, because this bike uses an internal hub. The only issue is that because of the exposed chain,my leg sometimes touches the chain or chainring, leaving a mark on my leg.

Thus I sourced for a suitable 50T chainguard with a 110mm BCD. Ironically it is a Driveline branded chainguard.

The chainguard that comes with longer chainring bolts

Less common specifications, 50T with 110 BCD. Found only on compact cranksets.

At the same time, I also got new pedals for the Flamingo. The stock plastic pedals are starting to develop quite a bit of play, and the bearings are becoming less smooth. Thus I got another pair of folding pedals. The best folding pedals that I know of are the MKS folding pedals, which I had used since my very first folding bike in 2008.

MKS FD-6 folding pedals

Chainguard and pedals installed!

The black and white artwork on the crankset and chainguard matches well with the Flamingo logo on the frame

Installing the chainguard was not so straightforward as there is very little clearance between the chainstay and the back of the chainring, when the bike is folded. This causes the rear of the chainring bolt to scrape against the chainstay when I tried folding the bike. I had to try a few different combinations of chainring bolts and spacers before I could get a good setup that allowed the bike to be folded.

Damage caused by the chainring bolts, before I figured out how to solve the issue.

The eventual arrangement of spacers, chainring and chainguard that solved the problem.

Another thing that I changed on the Flamingo is one of the roller wheels. I had previously changed the whole set of roller wheels to enable better rolling. As one of the roller wheel fixing points was bent, I had to use a bent bolt to realign the roller wheel. You can read all about it here.

As a side effect of that, one of the roller wheels is at a different level from the other 3. That causes the bike to lean to one side, and only 3 wheels touches the ground at any one time, which makes it a little unstable.

To solve that, I bought wheels that are slightly larger, about 10mm larger in diameter. By changing one wheel, it allows all four of the wheels to rest on the ground when folded.

Larger wheel shown on the right, larger by 10mm in diameter.

One big one small! Looks funny but it works well. 

With the larger roller wheel, all four wheels can rest on the ground at the same time, making the folded bike much more stable.

Flamingo with the modifications. Crankset, chainguard, pedals and roller wheels.

Part 7: Cheap Bikes vs Premium Bikes: What is the Difference?

Before I continue with the article, I would like to thank all my readers, some of whom have given me valuable feedback and compliments. Without all your continued support and encouragement, I would not have found the inspiration and drive to write all these articles on my blog. Thank you!

The Drivetrain! It is the heart of the bicycle, without which the bicycle is just a Flintstone-style vehicle. The drivetrain is the system that transmits the power from the rider to the bicycle, powering you forward. A good drivetrain will be very efficient, using almost 100% of the rider's input to drive the bicycle forward. It is not possible to be 100% efficient, because energy losses are unavoidable. However, we can try to minimise the energy loss with good engineering. Let us first take a look at what the drivetrain of the modern bicycle consists of.


Components that make up the drivetrain:
1) Bottom Bracket (BB)
2) Cranks
3) Chainring
4) Chain
5) Cassette sprockets

Useful accessories that help to keep the drivetrain running properly:
1) Chainguard
2) Bashguard

Now for the comparison! I don't have complete information on the Aleoca R2R's drivetrain, so I will give it my best shot at guessing the parts, and give it the benefit of the doubt. Hope it does not affect the credibility of the comparison too much!

Bottom Bracket (BB)
The bottom bracket, also commonly known as the BB, is the core of the drivetrain. For the square taper BB used for both the Aleoca R2R and the Dahon MuP8, the BB has bearings at either end of the BB, together with the square taper axle.

The square taper BB has been around for a long time, and is still very commonly used nowadays. It is also cheap, and nowadays people don't service square taper BB's. When it wears out, it is much easier to just change out the BB.

The BB screws into the bottom bracket shell on the frame of the bike. Point to take note is the direction of the screw thread used. To loosen the BB from the frame, the BB cups have to be turned in the pedalling direction. This helps to prevent the BB cups from tightening further during pedalling, which will make it impossible to remove in the future. The BB cups will have a left-hand thread on the right side, and right-hand thread on the left side. Confusing?

Aleoca R2R Bottom Bracket: Square Taper (Cup & cone bearings with ball retainer)
Dahon MuP8 Bottom Bracket: Square Taper (Cartridge type, sealed bearings)

Cartridge-type BB on top, Loose bearing type at the bottom. Note the difference in the number of parts!

The excellent picture above shows the difference between a cartridge-type BB and a loose bearing BB. The cartridge-type is non-serviceable, you just replace the whole unit when it is broken.

Both the BB's are square taper BB. When mounted on the bike you cannot really tell the difference. The difference is in the construction. The Aleoca R2R uses an older type of square taper BB, with loose bearings (kept together with a ball bearing retainer) that can be serviced. This is the same stock BB used on the Dahon Vitesse D7. The disadvantage is that it is not as well sealed against dirt and water as the sealed bearing type. Since BBs are rarely serviced nowadays, there is hardly any advantage to be able to service the bearings. Just change the BB!

The Dahon MuP8's square taper BB is the newer type, with sealed bearings that come from the factory almost fully assembled. You just need to screw in the cartridge from the right side, and then insert the left side BB cup. Cartridge type refers to the construction, where the BB comes as a cartridge that you can just change out as a single unit. This type of BB is better sealed against the elements, thus it should be more durable.

Comparing these 2 BB's, there is frankly not much difference here. Cost savings are made here since it cannot be seen by the user anyway. Performance wise there isn't much that can go wrong here, even cheap BB's will perform decently.

Cranks
The cranks link the pedal to the chainring, which in turn pulls the chain and drive the rear wheel. To be efficient, the cranks have to be very stiff to endure the high forces that the rider exerts on the drivetrain. The ultimate crank would be super stiff and ultra lightweight. Carbon cranks come close, but at a high price! Nowadays, cranks are mostly made out of aluminium, because it is relatively lightweight and strong.

Aleoca R2R Cranks: Cold-forged aluminium, crank+chainring
Dahon MuP8 Cranks: Kinetix Supra Crank, forged aluminium

Cranks that come attached with chainring. Similar to the type found on Aleoca R2R.

Kinetix Supra crank. Note the 5-bolt chainring mounting and the beautiful surface finish!

Aluminium cranks are always cold-forged for strength, which is especially important for cranks. It would be very "exciting" and dangerous if your crank were to snap while pedalling hard!

The main difference here is the way in which the chainring attaches to the right-side crank. For the Aleoca R2R crank, the chainring is permanently press-fitted onto the crank with a splined interface. Good system, just that you cannot change out your chainring if it wears out or if you want a chainring with different number of teeth.

The Kinetix Supra crank uses the 5-bolt mounting with 130mm bolt circle diameter (BCD). This is a pretty standard mounting for most road bike cranksets nowadays, which means that you are free to change your chainring as you please. What stands out here is the polished surface finish of the Kinetix Supra crank! Really beautiful finish that greatly elevates the aesthetic value of the cranks.

Chainring
The chainring drives the chain, and by varying the number of teeth on the chainring, you can alter your gear ratio. Some strong riders like to change their chainring from the standard 52T chainring to a larger 56T or even 60T chainring to compensate for the smaller wheel size of the 20" bikes. Since there is no front shifting for these two bikes, there is no need to get highly engineered chainrings (with ramps and pins and profiled gear teeth for optimum front shifting) used for bikes with double or triple chainrings.


Aleoca R2R Chainring: Steel chainring
Dahon MuP8 Chainring: Aluminium 6061 chainring

Typical aluminium chainring with 130 BCD mounting.

Main difference here is the material! A steel chainring is very durable, but it is heavy and may be prone to rust after some time. Aluminium chainrings are the norm nowadays, being light and strong. A chainring can always be replaced if it wears out, which is possible only if the standard 5-bolt mounting, such as those found on the Kinetix Supra crank is used.

With the 5-bolt mounting, the mounting points of the chainring onto the crank is much closer to the edge of the chainring. This reduces the likelihood that the chainring will be bent during transportation or usage, as the chainring is better supported by the crank spider. This contrasts with the one-piece crank+chainring set found on the Aleoca R2R, where warping of the chainring is much more common.

Chain
Not much to compare here, pretty standard chains used for the bikes! A nicer chain would usually be nickel or chrome plated for better appearance and corrosion resistance. The most important aspect is not the surface finish of the chain, but how you take care of the chain. As long as you remember to clean and lubricate the chain regularly, even the dull looking cheap chains will run nice and smooth.

Typical bike chain. Dull surface finish.

Dura-Ace 10 speed chain with durable zinc-alloy silver finish for corrosion resistance.

In the previous post of the bike comparision article, which is Part 6: Gear Shifting System, I mentioned that the recommended chain for an 8 speed system should be an 8 speed chain. (6,7,8 speed chains are the same). However, you can also use a 9 speed chain on an 8 speed system with not much of a problem. Being narrower, the 9 speed chain should run quieter, as it is less likely to rub on adjacent sprockets, especially when cross-chaining. The compromise here is the gear shifting, where it might be hesitant to downshift (change to lower gear), as the chain is narrower and will not climb as well onto the larger sprockets. But it is usually not a big issue. Just don't use an 8 speed chain on a 9 speed drivetrain, as the wider 8 speed chain will be too wide to fit properly on the narrower 9 speed sprockets!

Cassette Sprockets
In the previous part, the cassette sprockets were discussed when the gear shifting systems were compared. The sprockets are also part of the drivetrain, as the sprockets drive the freehub, which then turn the rear wheel. This will not be discussed further as it has already been compared in Part 6: Gear Shifting System.

Chainguard and Bashguard
Other little parts that complement the drivetrain would be the chainguard and the bashguard. The chainguard and bashguard are commonly mis-labelled, with the bashguard also being called the chainguard.

Strictly speaking, the chainguard is the little black tab that wraps around the seat tube, which helps to prevent the chain from falling inward off the chainring. The bashguard is the large disc that encircles the chainring, preventing the chain from falling to the outside of the chainring. With these, the chain will stay on the chainring, and not fall off when shifting too quickly or riding over bumpy terrain.

Aleoca R2R: 2-piece plastic bashguard
Dahon MuP8: Chainguard and alloy bashguard

2-Piece plastic bashguard. Sandwiches the chainring to prevent chaindrop.

Black chainguard and edge of bashguard shown. Together, they prevent chaindrop.

The very stylish bashguard that was on my Boardwalk! It has since been removed as I have added a front derailleur (FD), and the FD will prevent chaindrop.

An alloy bashguard would be more durable and resistant to damage compared to plastic bashguards. But performance wise, there is no difference here. It does not contribute to drivetrain efficiency, although it may improve the appearance!

Comparing the drivetrains, the significant differences are the cranks and also the chainring. Other than that, the other components are quite similar. I would have expected the Dahon MuP8 to have a better BB, such as a Shimano Octalink BB (stiffer and more efficient). However, this would mean upgrading the crankset too, which I guess is not possible if they need to keep the production costs down.

One good thing is that the Dahon MuP8 frame is a good frame, thus it is worth upgrading the drivetrain to a Shimano Hollowtech II drivetrain. The Hollowtech II drivetrain is much stiffer and also lighter at the same time, making the drivetrain more efficient as less energy is lost to the flexing of the BB axle and also the cranks.

You can read the other parts of the article at the links below!

Cheap Bikes vs Premium Bikes: What is the Difference?
Part 1: Frame & Fork
Part 2: Frame & Fork (continued)
Part 3: Contact Points and Steering System
Part 4: Wheels and Tires
Part 5: Braking System
Part 6: Gear Shifting System

In the next and last part of this article, other less well-defined aspects of the bikes will be discussed and compared. Examples would be the folding joints that are used on the bike, and the Pre-Delivery Inspection (PDI) conducted by the bike shop before selling the bike to the consumer.

Check out Part 8 here!
Part 8: Folding Joints and Miscellaneous Stuff

fortgesetzt werden!

Preparing the bike for King of Da Hill !

This coming weekend, we will be conquering all the hills at the southern and western part of Singapore! Some of the hills include Mount Faber, Bukit Chandu, Kent Ridge Park etc. I have not been to any of these hills before, so it will be an interesting trip for me!

Can't say that I have been training much for this, nor can I say that I am well prepared. But no matter what, I'm just going to have fun! I have heard that it is very difficult to get up some of the hills on a 53T Front/28T Rear combo, with a 20" wheel bike. Not good news for me, because that is the exact same lowest gear ratio that I have!

Some of the KODH participants have a double chainring up front, which makes it much easier to cycle up the hills with the lower gear ratios. However, for those of us who only has a single chainring up front, there is a limit to how low the lowest gear can go, without affecting the top gear too much.

With my Dahon Boardwalk, I have 9 speeds, with a 53T chainring in front and the largest sprocket at the rear being 28T. To get a lower gear ratio, I will need to have a larger rear sprocket or a smaller front chainring.

Contemplated getting a front derailleur adaptor for the Boardwalk, so that I can fix a FD and add the 39T chainring up front, to give me a 2x9 gear system. However it is quite troublesome, since I will have to fix the adaptor, FD, front shifter, cable housing. Also, I can't see myself using the 39T chainring other than for KODH or for touring?

Another solution is to change the cassette to one with a larger sprocket, such as 32T. However, this is also not as straightforward as it seems. Because of the larger sprocket size, my short cage X9 RD will not be able to handle the 32T gear. Short of changing the RD, I also cannot use a different cassette.

Finally, I hit upon another solution, which is to change the current chainring size! From the current 53T chainring, I can change it to a 45T chainring, which lowers all my gear ratios by 15%. Although I lose the top end speed, I gain by having a lower gear ratio to use while climbing the hills. This is a temporary arrangement, all for the KODH challenge!

Brought out my new bike workstand from X-Tools which I bought about 2 weeks ago! Ordered it online at CRC, had it shipped over and it is still cheaper than buying locally, haha. It is of good quality too!

Being able to fold the workstand is very important, as I can put it in one corner and not have it take up space when not in use.

Sturdy large diameter tubing, adjustable height and angle.

Solidly built clamp head, with cleverly designed latching mechanisms and easy adjustments.

Lever with cam profile allows quick clamping and loosening of bike.

Ta-da! All set up and ready for use! It only takes 15 secs to set up the workstand!

Although the workstand has a rubber clamp area, I still prefer to use a separate old seatpost for clamping, instead of my black seatpost. With the workstand, it is now much much easier and comfortable to work on the bike, since the wheels and cranks can spin freely without the kickstand or the ground getting in the way.

Note the different seatpost that I use. Very sturdy and stable workstand!

45T chainring with bash guard. Lowers my gear ratios by 15% compared to the 53T chainring.

An issue which I overlooked was the fact that the chain length would not be correct, since the chainring is now smaller. In fact, at the smallest sprocket at the back, the chain actually becomes loose! Luckily I could still adjust the B-tension screw on the RD to take up the slack on the chain. That was not the original design intention of the B-tension screw, but it works, and it is only temporary so it is fine. Shifting is not as crisp because the guide pulley is now further away from the sprockets, but again it is fine because it is only temporary.

Will be testing out the new system very soon, hope it works well and comes in useful for KODH!

New Bashguard for my Boardwalk!

Just got some new stuff to "zhng" my bike today! Remember the last time when I added a bashguard to my bike? It is to prevent chain drop, which tends to happen when I upshift when pedaling down a slope. I am happy to report that after installing the bashguard, there has been no chain drop issues at all! I can pedal and change gears whenever I like without fearing that the chain will drop off the chainring.

However, the bashguard which I installed the last time was gold in colour. Even though gold is part of my bike's colour scheme, the big disc of gold stands out too much and does not fit the overall look of the bike. The new black bashguard looks so much better! Also, I get to use my gold chainring bolts hahaha...