Saturday, January 26, 2019

Java Neo 2 vs Dahon MuEX

How does the Java Neo 2 folding bike compare to other folding bikes? After introducing the main features and specifications of the bike in Part 1 and Part 2, let us now compare it with another bike. In this case, it is fair to compare it with a Dahon folding bike as both bikes are using 20" 406 wheelsets.

For comparison, I used the Dahon MuEX as that is the only 20" folding bike that I have currently. For those who know, the Dahon MuEX is a high end Dahon folding bike, with many top level and lightweight components. However, for this comparison, I will not be comparing the bike weight or components specifications, as components can be changed easily. Furthermore, it is not fair to compare the stock components of the Java Neo 2 to the upgraded components of the Dahon MuEX.

What I will compare is generally the bike geometry and size, plus other features such as ease of folding. The Dahon MuEX geometry will be representative of most other 20" Dahon folding bikes. First, let's look at the wheelbase and overall length of these two bikes.

Same as for other bike geometry comparisons, I used the centre of the bottom bracket as the datum for aligning the bikes.

Chain stay length of the Dahon MuEX is slightly longer than the Java Neo 2, by about 10mm.

Distance from front hub to bottom bracket is also longer on the Dahon MuEX, by about 25mm.

Bottom bracket on the Java Neo 2 is higher than the Dahon MuEX, which is quite unusual. This might be due to the folding rear triangle design which requires this.

What this means is that the wheelbase of the Java Neo 2 is shorter than the Dahon MuEX, while the bottom bracket is higher. This means less stability on the Java Neo 2 as the wheelbase is shorter, while the centre of gravity is higher due to the higher bottom bracket.

Java Neo 2
Chainstay length: 390mm
Wheelbase: 985mm
BB height: 310mm

Dahon MuEX
Chainstay length: 400mm
Wheelbase: 1020mm
BB height: 284mm

Height of top tube (or main frame) is about the same at the head tube area. However, the Dahon MuEX frame curves downwards near the seat tube. This means that step over height is about the same.

How about the folded size? This is a very important factor as a folding bike needs to fold easily and compactly, in order to justify the higher weight and cost compared to a non-folding bike of the same specifications.

When folded, the Java Neo 2 is about the same length, but is quite a bit taller, due to the long seat post and the high seat tube. This is a big issue for me as I cannot fit the Java Neo 2 upright into the back of the car, unlike the Dahon MuEX.

For folded width, both bikes are about the same, even though the Dahon MuEX handlepost folds inwards while the Java Neo 2 handlepost folds outwards.

Up till now, we can see that the Java Neo 2's folded size is taller than the Dahon MuEX, even though it has an innovative new folding design. In my opinion, if a new folding design does not result in a more compact fold or easier fold, what is the point? It may be cool or interesting to have a new folding method, but it has to be at least equal in size to the market standard, which is the Dahon fold.

If a new folding method results in a smaller folded size, it may be acceptable to have a more complicated fold. Or, if the folded size is larger, but is easier to fold, it may also be acceptable. Some other folding bikes also have a larger folded size plus a more complicated fold, but they have other features. For example, the Birdy fold is larger and more complicated than a Dahon, but it has full suspension. A Tyrell FX also folds larger and is more complicated than a Dahon, but it rides very well due to the rigid frame.

However, in this case, the Java Neo 2 has a larger folded size, plus a more difficult fold (refer to Part 2), with no other feature that makes it better than a Dahon.

Let's check out the weight of some stock components. From what I see, the handlepost can be easily upgraded to a more lightweight type (non-adjustable), while the handlebar components (shifters, brake levers, grips) are more or less standard with similar weight no matter what you upgrade to.

The stock crankset is a square taper type, which is quite heavy. Upgrading to a Hollowtech II type of crankset and bottom bracket will save quite a bit of weight. The exact weight is not known as I will not be disassembling those parts.

However, other components that are easily removed will be weighed, such as those shown below.

Weight of super long seat post (650mm) plus stock saddle is 761 grams. In comparison, a Litepro seatpost (320g) plus a mid range saddle (230g) will weigh just 550 grams.

Weight of high profile front wheel (wheel + tire + tube + rotor + QR axle) is 1639 grams. In comparison, a Wheelsport Smart front wheel (584g) + Kojak (230g) + tube (100g) + rotor (125g) + QR axle (50g) will be just 1089 grams. Much room to save weight here.

Weight of high profile rear wheel (wheel + tire + tube + rotor + QR axle + cassette) is 2083 grams. In comparison, a Wheelsport Smart rear wheel (793g) + Kojak (230g) + tube (100g) + rotor (125g) + QR axle (65g) + cassette (300g) will be just 1613 grams.

From this, we can see that the stock high profile wheelset is quite heavy. Changing to a mid range Wheelsport Smart 1.0 wheelset plus better Kojak tires would save you 1 kg, while keeping the other parts the same. If you spend more for high end parts (lightweight wheelset and tires, titanium QR axles, etc), you can save another 300 grams or so from just the wheelset.

With these weight estimates of the various bike components, plus the weight of the overall bike, I was able to make a rough estimate of the frame weight (main frame + rear triangle only). This is just an estimate as I do not have the exact weight of many other components, but it should be around this range.

Full bike weight is 12.3 kg without pedals in stock condition. After deducting the weight of all the components, the estimated frame weight is 3.6 kg. This does not include the front fork. For comparison, the other bike frame weights are shown below. Some of these weights include the rear derailleur hanger or seat post clamp, or the headset weight, so the comparison is not exactly accurate, but the general trend is there.

Frame only weight estimates (excluding fork)
Java Neo 2: 3600 grams
Dahon MuEX/MuSP: 2400 grams
Crius AEV20: 2440 grams
Java Freccia: 1060 grams
Canyon Endurace: 807 grams
Fabike C3: 1296 grams

Note that the Java Freccia, Merida Scultura 5000, Canyon Endurace, and Fabike C3 are carbon frames, while the others are aluminium frames.

From this frame weight comparison, we can see that the weight of the Java Neo 2 is not competitive at all, being much heavier than the aluminium Dahon frame. The carbon frame version of the Java Neo will weigh less, but it will also cost a lot more.

Disadvantages of Java Neo 2 compared to Dahon
1) Taller folded size.
2) Long seat post is necessary for folding, cannot change to shorter and lighter seatpost.
3) Frame is heavier than Dahon.
4) Folding and unfolding steps is awkward.
5) Some lateral flex (between seat tube and rear triangle) at rubber stopper area.
6) Not possible to change to 451 wheels as it will affect the folding.

Advantages of Java Neo 2 compared to Dahon
1) Drivetrain is tucked inside when folded.
2) Can lay the frame down on the side easily, ideal for putting into car boot lying down.
3) Frame folding lever is nicely integrated into the frame.

My initial intention of getting the Java Neo 2 folding bike was to see if it is good enough to replace the Dahon MuEX. If it was, I planned to transfer all the compatible components from the Dahon MuEX to the Java Neo 2. However, after comparison, the Java Neo 2 loses out to the Dahon MuEX in almost every aspect. Note that I did not compare the components specifications, just mainly the frame weight, the folded size, and ease of folding.

The conclusion for me is that the Java Neo 2 is not good enough to replace the Dahon MuEX. On its own, the Java Neo 2 is a decent folding bike. With its unique folding design and sharp appearance, it looks quite good. However, in my case, it is not better than a Dahon in terms of weight, folded size or ease of folding.

Friday, January 18, 2019

Java Neo 2 Folding Bike: Introduction Part 2 of 2

Continuing from the first part of the introduction to the Java Neo 2 folding bike, let's take a closer look at the folding method and design!

The most interesting feature of this new folding design is the way the rear triangle is folded. On other bikes with folding rear triangles, the pivot will be located behind or in front of the bottom bracket, such as on the Brompton, the Birdy, the Bike Friday or the Dahon Curl. This is done for practical purposes, as locating the pivot away from the bottom bracket is much easier for manufacturing and design.

However, if the rotation centre of the rear triangle is not the same as the centre of the bottom bracket, there will be a change in chain stay length during folding. This is a major limitation for all these folding bikes, where an additional chain tensioner or chain catcher is needed to prevent the chain from falling off the chain ring during folding or unfolding. At the same time, installing a front derailleur on these kind of bikes with a folding rear triangle is challenging due to the movement of the chain during folding.

The Java Neo 2 does the folding of the rear triangle differently. By letting the rear triangle pivot around the bottom bracket, the centre of rotation of the rear triangle is the same as the centre of the bottom bracket. In other words, the chain stay length is constant whether the bike is folded or unfolded. Therefore, there is no need for any additional chain tensioner or chain keeping device to prevent the chain from dropping off, and this is the main advantage.

This is not a new idea, but it is the first time that I saw it being implemented for a mass production bike. It is challenging to design the rear triangle pivot such that it rotates around the bottom bracket, as there is limited space and width at the bottom bracket area.

Another advantage of this folding bike is that practically all components on the bike are standard components, without the use of proprietary parts such as on the Brompton.

Other than the folding method, I also like the use of disc brakes, which have a better braking performance than rim brakes in almost all weather conditions. Although it is heavier, it is an acceptable trade off for better braking performance.

Instead of writing any more, let's look at the pictures of the new Java Neo 2!

Java Neo 2 with the special rear triangle that folds and pivots around the bottom bracket.

To release the rear triangle, press down on this lever located on top of the rear triangle. Also note the transparent elastomer that the seat tube will rest on when you ride the bike.

Once the lever is pressed, it will release the hook that holds the seat tube to the rear triangle.

A bit difficult to see clearly, but the hook catches a protrusion which is mounted on the seat tube. This is what prevents the rear triangle from detaching when you lift up the bike. Similar in concept to the Brompton.

This is the little aluminium protrusion that the rear triangle will catch on. Although it is not under load when you ride the bike, the aluminium piece looks quite small and weak, and might break off under the stress of repeated folding and unfolding. Luckily it is replaceable.

Another highlight of this folding bike is the latch for the main frame folding. Lever is nicely integrated into the frame without protruding outwards, plus a nice red dial that is the secondary safety catch to prevent accidental opening of the latch.

The latch works by holding the two halves of the frame together. As you can see, the shaft on the latch will press against the pin on the frame when the latch is closed. Safety catch at the right side works similarly to your mailbox lock.

Another view of the folding joint, and how the latch is integrated into the frame.

I found that the latch kept getting looser as I opened and closed it, and found that the bolt that adjusts the tightness of this latch is very loose. I had to add loctite to the threads as shown by the red arrows to prevent loosening. There was a split washer but it was not effective at all.

Similarly, I added loctite to the set screws to prevent self loosening and a chance for the hinge pins to fall out.

As for the handlepost, the folding mechanism is slightly different from what I have seen on Dahon or Tern, but the concept is the same. Shown here is the bolt that is used to adjust the tightness of the handlepost folding lever.

Uses a large threaded bolt to secure the handlepost to the steerer tube, same as the Dahon. Note the top section of the handlepost at the left side, which allows the handlepost to be raised to unrealistic heights.

Folding the Java Neo 2 is actually not so easy. Although the folding mechanism is nicely designed, with a well designed swinging rear triangle and a folding main frame, the actual process of folding and unfolding the bike is quite awkward and cumbersome. I shall attempt to describe the folding process and steps below in words, as there is no way to take pictures during folding because both hands are needed from start to finish. Please try to visualize it for now, I am sure someone else will upload a video of it in the near future.

Folding the Java Neo 2:
1) Raise the seatpost so that it does not protrude from the bottom of the seat tube. Yes you need to raise it, not lower it.
2) Open the latch on the frame (with the open/close switch), and fold the hinge slightly.
3) Press the folding lever on the rear triangle, and lift up the frame so that the rear triangle swings downwards.
4) While the frame is lifted, use your foot to push the rear wheel inwards such that it swings under the frame. This is similar to folding the Brompton.
5) At the same time, you need to fold the front half of the frame, or the front wheel will block the rear wheel from tucking in under the frame. This is the difficult part, trying to fold the front and rear of the bike at the same time.
6) Once the rear wheel is tucked under the frame, the front wheel should also rest beside it. There is a hook beside the front fork (shown in the pictures below) which needs to hook onto the right side chain stay. This hook is difficult to engage as it tends to snag on the outer casing running on top of the right side chain stay.
7) At this point, the handlepost is still not folded, while the seat post is still high up in the air. You have to keep holding the bike or it will fall over!
8) Now, you can lower the seat post all the way down until it touches the ground. At this stage, the folded bike is balanced.
9) Finally, fold the handlepost and rest it beside the front wheel.
10) The bike is able to balance itself when fully folded, but not when half folded.

Unfolding the bike is comparatively easier, as you can use gravity to help you unfold the front fork and the rear swing arm at the same time, similar to the Brompton method.

I wondered why the stock seat post (diameter 33.9mm) is so long at 650mm, as other folding bike seatposts are usually around 560mm to 600mm maximum. Is it possible to change to a shorter seat post?

When the rear triangle is folded, the seat post needs to be raised higher, to prevent it from blocking the movement of the rear triangle. This is an additional step which is not found on other folding bikes.

This is the hook on the right side of the front fork. It will hook onto the right side chain stay when folded. Strange to see the hook covering the Neo logo...

When folded, the front fork and right side chain stay will be next to each other. The hook needs to be engaged to prevent the rear triangle from dropping down when you lift the folded bike.

Java Neo 2 full folded! The reason for the long seat post is so that it can reach the ground and balance the bike. If a shorter seat post is used, the folded bike will fall over.

Handlepost folds outwards and rests on the side of the front wheel. A longer handlebar (stock width is 540mm) will result in a larger folded size.

Folded width is quite decent, but note that this is without pedals. In a separate post, this Java Neo 2 will be compared to the Dahon MuEX.

The rear brake cable and shifter cable runs between the seat tube and the rear triangle, on both sides. Note that sufficient cable slack is necessary to allow proper folding.

While studying the bike, I also checked the clearances so that in the future, if anyone wants to upgrade or change the components, here is a reference to see if it is possible or not.

Some clearance between chain and seat stay. Possible to use a larger chain ring or larger cassette.

Small clearance between chain and frame, need to take note if chain line is adjusted, such as if the crankset is changed.

When the rear derailleur is in the lowest gear, the cage goes quite close to the rim and tire. Probably cannot change to a long cage rear derailleur as the cage will touch the tire, unless you use a narrower tire.

Some of the features of this bike printed on the seat stay, although it doesn't mean anything to me.

Full bike picture! The lines of the frame have an angular look with hardly any rounded corners.

View from the drive side. The black components and high profile wheelset matches this frame quite nicely.

Other specifications of this bike are shown below
Weight: 12.3 kg in stock condition without pedals
Wheelbase: 985 mm
Chain stay length: 390 mm
Bottom Bracket height: 310 mm

With a stock weight of 12.3 kg, this bike is not lightweight. In fact, for an aluminium frame folding bike, this is considered rather heavy, as most other aluminium frame folding bikes at this price range weighs less at 10+ to 11+ kg.

As for the other specifications such as chain stay length, it is not useful data on its own, as we need to compare it to another bike. This will be done in another post, where this Java Neo 2 will be compared in detail to the Dahon MuEX, which is used to represent a standard folding bike.

Friday, January 11, 2019

Java Neo 2 Folding Bike: Introduction Part 1 of 2

New folding bikes are introduced every year, but it is rare to see a new folding method that is different from previous designs. There are two main types of folding methods that are popular, which I will call the Dahon method and the Brompton method.

The Dahon folding method has a hinge in the middle of the main frame, plus a folding handlepost. Most folding bikes use this method, as it is simple and straightforward. However, it is not the most compact method.

Another type is the Brompton method, where the rear triangle swings below the main frame, while the front half of the frame is folded. A variation of this is seen on the Birdy folding bike and the Tyrell folding bike, where the front fork folds and tucks the front wheel inwards. This method is quite compact, but a chain tensioner or chain keeper is needed to prevent the chain from dropping off during folding.

This new Java Neo 2 folding bike uses a hybrid of these folding methods, plus some new ideas, to create a really unique folding design. The first generation is actually the Java Neo, which is the carbon frame version of this folding bike. The Java Neo 2 is the aluminium frame version which is cheaper and also heavier.

The stock components on the carbon Neo and the aluminium Neo 2 are also different, to meet different price points. On the carbon Neo, the stock drivetrain is 1x11 speed, while the Neo 2 has a 1x9 speed drivetrain. Most other components such as brakes and crankset are also different. As for the price, the aluminium Neo 2 costs just 40% of the original carbon Neo.

Before we look at the innovative new folding method, let's take a look at the stock setup of the 1x9 speed Java Neo 2.

Java Neo 2 folding bike, with a nice looking frame shape. I'm not a big fan of the colour schemes though.

Neo 2 model name indicated on the main frame (top tube). The paint finish quality is quite good.

Flat handlebar setup (540mm wide), with a Deca aluminium handlebar and OEM lock on grips. Top of handlepost has a quick release clamp which is the same design as a Dahon/Fnhon handlepost.

Shimano Altus SL-M2000 9 speed MTB shifter, with OEM brake levers.

Other than the top clamp, the height of the handlepost is also adjustable. I don't like this as it tends to rotate even when the lever is adjusted to clamp very tightly, plus it adds unnecessary weight.

Handlepost clamp, somewhat similar to older Dahon handleposts or the Tern handlepost. Looks bulky but works well.

Java logo found on the head tube. Large welds on the aluminium fork is unsightly, after I am used to the smooth finish on the Dahon MuSP.

This locking lever plus safety catch on the main frame looks very good. It is nicely integrated into the frame, with a little switch to act as a safety latch to prevent accidental opening of the lever. Note that this switch is not found on the carbon Java Neo.

Hinge near the front of the main frame, similar in position to the Brompton. Once again, good paint quality can be seen here.

Although the paint quality is good, the welds are not polished, giving a very rough and cheap appearance.

A little bit of internal cable routing here, with the rear shifter and brake cables entering the main frame, and exiting just in front of the bottom bracket area.

Cables exit here, and go to either side of the seat tube.

There must be sufficient cable slack in order for the rear triangle to fold without being overstretched. Also, the rear triangle pivots around the centre of the bottom bracket, meaning that chainstay length is always constant.

On the left side, the rear triangle is tightened into the central bottom bracket unit, using the black part which can be turned using a pin spanner. Not too sure how a Hollowtech II bottom bracket will be fitted as space is limited.

Drivetrain as seen from the right side. Crankset comes with a 52T chainring that is removable, with an integrated chainguard.

Square taper type of bottom bracket, with a square taper crankset. Simple and works well but is rather heavy compared to Hollowtech II type.

Sora RD-R3000 9 speed rear derailleur, with an unknown 11-28T 9 speed cassette and KMC chain.

Front wheel has a high profile aluminium rim (estimated to be 40mm tall), 24 spokes, with a 160mm 6 bolt disc brake rotor.

100mm front OLD, with quick release axles and a mechanical disc brake caliper. Brake caliper mounting requires an adapter to convert the IS mount to Post Mount type.

The front fork has eyelets which I presume is for front mudguard mounting.

Rear brake caliper mounting is of the Post Mount type, but an adapter is still required. 135mm rear OLD, with a similar 160mm 6 bolt rotor.

Rear wheel also has a spoke count of 24, and uses the same mechanical disc brake caliper.

Stock CST tires have a dimension of 40-406, which is quite wide. The rated PSI on the tire is only 35-45 PSI!

Deca branded OEM saddle which is of decent quality. Attaches to the seatpost with a clamp design that is similar to Litepro seatposts.

In the second part of the introduction, I will share more regarding the folding mechanism and method for this Java Neo 2 folding bike. We shall see what is special about the new folding method and mechanism that makes it unique!