Thursday, October 4, 2018

Fabike C3: Frame and Fork

What are the important attributes that a commuting bike should have? For a start, it should be able to handle all kinds of weather, especially rain in Singapore. Of course there is no snow here, but that is extreme and will require a special kind of bike.

In Singapore, there is only rain or sunshine. Any bike can handle sunny days, but not so many bikes are able to handle wet weather well. By handling, I mean being resistant to rust even when not serviced after riding in the rain. Normal bikes with derailleurs cannot handle wet weather well, as there are many parts in the drivetrain that are prone to rust, such as the chain, cassette, derailleur.

As for braking, rim brakes don't perform well when the rims are wet. Without a doubt, hydraulic disc brakes are more superior in this aspect, as they maintain excellent braking performance regardless of weather.

Lastly, a commuter bike must be able to maintain its function well even when not being serviced much. Although a bike with derailleur can be ridden in the rain, it needs to be serviced quite often, or the drivetrain will rust and not work well.

A summary of features to look for in a good commuting bike was already prepared before, just check out the link for the details.

Key requirements for a good commuting bike:
1) Disc brakes, with hydraulic type strongly preferred for more power
2) Belt drive, to make it maintenance free
3) Internal hub, to have multiple gears for efficient pedaling, and yet low maintenance
4) Mudguards to prevent road spray when riding over wet roads
5) Stainless steel hardware on bike to avoid rust

My previous commuting bike, the Avanti Inc 3, satisfies all these conditions. As with most of my bikes, I have modified and upgraded the parts extensively from the original components, until only the frameset is left.

The Avanti Inc 3 is a good bike and I have no regrets getting it, but I had 2 main complaints about it.

1) Aluminium frameset seems to be quite heavy, made even worse by the internal hub (+1 kg from normal derailleur bikes, based on whole system)
2) Unusual geometry. It is a small sized frame but with a long top tube and short seat tube. This means a less responsive ride, and also requires a very short stem to work. Probably works well for a trekking bike, but not for a road bike style which I preferred.

Other than these issues, it is a perfect commuting bike. I had upgraded it to a drop bar bike with Alfine 11 Di2 shifting, but it still does not ride like a road bike due to the geometry and the weight.

I have considered getting a new frameset to replace the Avanti Inc 3, but it is difficult to find a suitable frameset, especially a carbon fibre frameset with the requirements listed below.

Main requirements for the frameset:
1) Carbon fibre frame for lighter weight.
2) Belt drive compatible. This means having a split seat stay design.
3) Eccentric bottom bracket is strongly preferred for belt tension adjustment.
4) Mudguard mounting points are necessary.
5) Internal hub compatible, with rear 135mm OLD.
6) Disc brake compatible, with Flat Mount preferred for a cleaner look.
7) Road bike geometry, as it is my preference to have it ride similarly to the Canyon Endurace.

If you try to Google for such a frame, it is impossible to find a frame that has all these features. From what I see, the rarest combination of feature is to have a carbon frame that is belt drive compatible.

I chanced upon a picture of a belt drive bike by Fabike, which seems to have some of the features listed. After emailing Fabio from Fabike, I found that they were actually developing a new frame, the Fabike C3, which has all the features that I wanted! Fabio was also very patient and detailed in answering all my technical questions.

The Fabike C3 frame was not quite ready for mass production yet, so I had to wait patiently while they got it ready. Finally, after some waiting, the frame was ready for purchase, although not through the official website yet. After making the online payment, the frameset was sent to me, which took a few weeks as it passed through a few countries.

Finally, the Fabike C3 frameset is here! The C3 frameset was first shown at Eurobike 2017, but even until now (September 2018) it is not offered officially yet. No matter, now I have the C3 frameset, and it satisfies all the requirements that I had.

Fabike C3 carbon fibre frame! Looks very much like a road bike frame. I was in between XS and S size, but Fabio recommended S size to prevent toe overlap as I wanted to install mudguards.

Headtube with the Fabike badge in blue, and the ports for inserting the Di2 wire and the rear brake hose for internal routing.

Integrated headset design, no need to press in any headset cups. Just place the sealed bearings in and you are ready to go!

Two bottle cage mounts are available! Very useful to have.

Integrated seat clamp design. There is a choice of colours for the anodized parts on the frame, I chose blue, out of the other choices of red, yellow, green, black.

Plate on the seat tube which covers a hole. You can install a front derailleur mounting bracket (not included) and leave it open to run a Di2 wire for the Di2 front derailleur. I don't think it is possible to run a mechanical front derailleur on this frame.

Bottom bracket shell. Press Fit 30 size, which means that you can install an eccentric bottom bracket using this! More on that in another post.

Flat Mount disc brake mounting on the left side chain stay. Hole for running the rear brake hose internally.

View from outside of the rear brake mount. Mounting point for mudguards on the seat stay, as shown by the bolt.

Mounting point for rear mudguards is hidden under the seat stay bridge.

Joint on the right side seat stay, which splits open to allow the installation of a belt. Also note the special dropout design.

Parts of the rear dropout includes the two special non-turn washers on the left and the two aluminium black axle bushes on the right.

Non-turn washers slot into the dropout, and the profile in the middle locks onto the hub axle which has two flat profiles, to prevent rotation.

The black axle bushes have a chamfered profile, which centers itself onto the chamfers on the dropout. Main purpose of this special dropout design is to avoid the use of conventional non-turn washers on the outside of the dropout which can be unsightly.

Frameset also comes with a carbon fork, which has a really long carbon steerer tube.

Oversized carbon steerer tube. Although the surface condition is not so nice, it does not matter as it cannot be seen once installed, and does not affect function anyway.

Internal routing for the front brake hose!

Brake hose exits near the front brake caliper. Also note the subtle Fabike branding on the inside of the fork legs.

Flat Mount brake caliper mounting, for a clean appearance.

12mm thru axle for mounting the front wheel, which is better for disc brakes. Location of the bolt indicates the mounting point for front mudguards.

Another view of the front fork legs

Mounting point for front mudguards is hidden at the back of the front fork

Weight of Fabike C3 frame includes seat post clamp, non turn washers and axle bushes shown here. 1296 grams, which is quite heavy considering that the Canyon Endurace frame weighs only 807 grams!

Weight of fork is including compression plug (28 grams). Actual weight of fork alone is 512 grams (uncut). Also considered heavy as the Canyon Endurace fork weighs only 361 grams.

The total frameset weight is thus about 1808 grams, not including the headset. From this, we can see that this is not a lightweight carbon frameset. In fact, the weight is similar to that of a good aluminium frameset that has a carbon fork (about 1400g + 400g).

Other than the weight, here are some other details of the frameset:
1) Seatpost diameter is 31.6mm. Due to the curved shape of the seat tube, it will only be possible to insert 120mm of the seatpost into the frame. This means cutting of the seatpost is almost guaranteed, as the insertion length has to be between 100mm (usual minimum insert length) and 120mm (maximum insert length allowed in this frame).

2) Wheelbase is 995mm, which is short for quick steering, just like a road bike.

3) Chainstay length is 415mm (BB centre to rear dropout, not accounting for eccentric BB adjustment). This includes the clearance for rear mudguards, which is impressively short. The Avanti Inc 3 has a much longer chainstay length of 444mm.

4) Thickness of rear brake mount (Flat Mount design) is only 7mm. This is thinner than the minimum of 10mm as recommended. I'm not worried about the strength of the mount, just that I will need to get the shortest bolt and still add spacers to make it work.
Recommended bolt lengths for different frame mount thickness.

The introduction of the Fabike C3 frameset is complete! Although this carbon frameset is not that lightweight, it is still quite a bit lighter than the current Avanti Inc 3 aluminium frameset. Also, it has some unique features that cannot be found in 99% of other carbon framesets, such as belt drive and internal hub compatibility, eccentric BB, Flat Mount disc brake mounting.

In the next few posts, we shall take a closer look at the other parts of the frameset, such as the special rear dropout, the eccentric BB and others.

Tuesday, September 25, 2018

Shimano Dura-Ace R9100 vs Ultegra R8000 vs 105 R7000: 11-30T Cassette

The 11 speed 11-30T cassette is a very versatile cassette, given its relatively wide range (for a road bike) and still has sufficiently close ratios due to the 11 gears. Previously, when a cassette was just 9 or 10 speeds, it is not ideal to have a low gear of more than 28 teeth, as the gaps between the gears will get uncomfortably big. Now, with 11 gears, it is possible to have a low gear of 30 teeth or even 32 teeth without sacrificing the gear steps.

This 11-30T cassette can be found on the 11 speed road groupsets, which are the Dura-Ace, Ultegra and 105 series. The gear ratios are exactly the same (11,12,13,14,15,17,19,21,24,27,30), as first seen on the Canyon Endurace. Differences are the material used, the construction, the weight, the surface treatment and of course the price.

Let's compare the Dura-Ace R9100 cassette with the Ultegra R8000 cassette, both of which are the 11-30T variety. Why does the Dura-Ace cassette cost twice as much as Ultegra cassette? Is it purely due to the use of the titanium sprockets in the Dura-Ace cassette?

Nomenclature:
R9100 - Dura-Ace R9100 cassette
R8000 - Ultegra R8000 cassette
R7000 - 105 R7000 cassette

R9100 has the largest two titanium sprockets (27T and 30T) mounted together on an aluminium spider

Weighs only 64 grams for these two sprockets, due to the use of the lightweight aluminium spider and the titanium sprockets.

Next 3 sprockets in the R9100 (19T, 21T, 24T) are also made of titanium, and are riveted to a carbon fibre spider.

Very lightweight due to the 3 titanium sprockets and the carbon fibre spider used in R9100.

As you can see, the Dura-Ace R9100 cassette has spared no expense to make sure it is as lightweight as possible, through the use of titanium for its 5 largest sprockets and the use of aluminium and carbon fibre spiders. Using titanium in the smaller sprockets (17T and below) will probably result in minimal weight savings at a much higher cost.

On the other hand, as the Ultegra R8000 is more cost sensitive, it will have to use a different construction and material to achieve a lower cost.

R8000 has the 3 largest sprockets (24T, 27T, 30T) mounted together on an aluminium spider

Weighs 135 grams for these three steel sprockets plus spider. Cannot compare directly to the Dura-Ace cassette as the number of sprockets mounted on the last spider is different.

R8000 has the 19T and 21T steel sprockets mounted together, on a carbon fibre spider

Weighs 49 grams for these two steel sprockets on the carbon fibre spider

At this point, we can compare the sub units of the R9100 vs the R8000, just for the last 5 sprockets.

R9100:
(27T & 30T) + (19T & 21T & 24T) = 64g + 59g = 123 grams
R8000:
(24T & 27T & 30T) + (19T + 21T) = 135g + 49g = 184 grams

For the last 5 sprockets alone, the weight difference is already 61 grams. The remaining 6 sprockets are mounted individually and are made of steel, so the weight should be similar regardless of Dura-Ace or Ultegra.

Weight of whole R9100 11-30T cassette is only 206 grams

Weight of whole R8000 11-30T cassette is 270 grams

Update: R7000 11-30T cassette weighs 295 grams.

If you compare the weight difference for the whole cassette, the Dura-Ace cassette is lighter than the Ultegra cassette by 64 grams, out of which 61 grams comes from the last 5 sprockets.

In other words, almost all of the weight difference between the R9100 and the R8000 11-30T cassettes come from the last 5 titanium sprockets!

If you are a weight weenie, you can save 64 grams from the cassette by choosing a Dura-Ace R9100 vs Ultegra R8000. However, if this weight difference does not matter to you, you can save quite a bit of money by using the Ultegra cassette which shifts just as well.

Update: The R7000 cassette uses one less aluminium spider in the construction compared to Ultegra, meaning there are more full spline steel sprockets being used, thus adding to the weight.

11 Speed 11-30T Cassette Weight Comparison
Dura-Ace R9100: 206 grams
Ultegra R8000: 270 grams (+64 grams & +31%)
105 R7000: 295 grams (+89 grams & +43%)

Friday, September 21, 2018

Dahon MuSP: Final Assembly

Finally, after much effort, plus trial and error, the Dahon MuSP has been completed! This is a folding bike with 451 wheels, drop bar and caliper brake setup, 1x11 speed drivetrain with Di2 shifting, and internal cable routing. Let's take a look at the final product!

Drop bar setup, with Ultegra Di2 shifters

Bar end type Di2 Junction A for a neat appearance

Controltech stem used to mount the FSA Vero compact drop bar on the Fnhon T-shaped handlepost

During folding, the rear brake outer casing will be scratched by the hole edges of the frame. This is quite a serious problem as the metal coil can be seen...

Di2 battery located behind the seat tube. The Di2 wire runs from the battery mount to Junction B (hidden inside frame), together with the rear brake cable through the same hole in the frame.

Top view of the battery location, which is hidden between the seat stays.

Di2 wire to the rear derailleur exits from the right side seat stay.

Blue Wheelsport Smart 1.0 451 wheelset, with Panaracer Minits Lite tires

Ultegra R8000 road caliper brakes, which fits on this bike without any modification or adapter required!

Ultegra 1x11 speed drivetrain

Wolf Tooth 46T chainring, mounted on the Ultegra R8000 crankset

Left crankarm of the Ultegra R8000 crankset

Blue Wheelsport hubs, which have a different shade of blue from the rims. Lightweight titanium quick release axles.

Another view of the Ultegra Di2 R8050 rear derailleur, and the 11-30T cassette


Stock lightweight kickstand from the Dahon MuSP, which only weighs 158 grams. Optional but very useful to have!

View of the completed bike from the non-drive side

View of the bike from the drive side. Blue accents on the frame makes it more special!

Full specifications of this Dahon MuSP. Weight without pedals and kickstand (usual standard for comparing weight with other bikes) is about 9.1kg.

Comparing the weight of this bike to a few other bikes which I have weighed, let's see where it stands. Flat handlebar and drop bar bikes cannot be compared directly, as the handlebar setup is different which makes a drop bar bike heavier than a flat handlebar bike. All weight comparisons are done without pedals, kickstand or any other accessories.

Flat Handlebar:
Dahon MuEX (1x11 speed Di2): 8.4kg
Crius AEV20 (1x11 speed): 9.1kg
Dahon Vitesse (2x10 speed): 10.5kg
Brompton M6R (2x3 speed): 11.9kg
Tyrell IVE (1x9 speed): 11.5kg

Drop Bar:
Dahon MuSP (1x11 speed Di2): 9.1kg
Dahon Boardwalk (2x11 speed Di2): 10.7kg (estimated)
Wheelsport Fantasy (2x11 speed Di2): 7.3kg
Java Freccia (1x11 speed): 6.4kg
Canyon Endurace (2x11 speed Di2): 7kg
Merida Scultura 5000 (2x11 speed Di2): 7.4kg
Merida Reacto 4000 (2x11 speed): 9kg
Avanti Inc 3 (1x11 speed Di2): 10.9kg

From this comparison, the 9.1kg weight of this Dahon MuSP is not too bad, as it is actually the second lightest folding bike, after the flat handlebar Dahon MuEX which is just 8.4kg. Non-folding bikes normally have a weight advantage as they don't need to strengthen the joints or have the folding mechanisms.

The handlepost used for this Dahon MuSP is still quite tall, despite getting one that is shorter (27cm) than the stock handlepost (31.5cm). There are handleposts that are even shorter (about 25cm), but they don't fit the requirement of a T-shaped, inward folding type.

As a result, the handlebar is still positioned relatively high, when compared to a road bike.

Dahon MuSP with the Controltech stem angled 45 degree upward/forward, which is the angle that I used when tesing this bike. Still a lot higher than the handlebar of the Canyon Endurace in the foreground.

As mentioned earlier, the main purpose of having the Controltech stem is to allow the handlebar to be placed BEHIND the handlepost, as it will be used for a smaller rider with a shorter reach. Therefore, let's see how it looks like when we actually rotate the stem to be behind the handlepost.

With the stem rotated to place the handlebar behind the handlepost, the handlebar is now lower as there is no vertical extension provided by the stem.

In this setup, the handlebar position looks to be just right for a shorter rider, as it is lower and further back.

This Dahon MuSP has finally been completed! I am happy with being able to install standard reach road caliper brakes on a folding bike, as it ensures good braking performance when paired with a road shifter. The internal cable routing is good because it makes the appearance much neater, especially with the bar end Di2 Junction A.

On the other hand, during folding and unfolding, the rear brake cable will slide through the hole on the frame, which causes it to be damaged by the sharp hole edge. This is a problem as the plastic layer on the outer casing will get scraped off easily, exposing the metal coil of the outer casing.

The solution is to minimize the folding of the bike, and also to carefully guide the outer casing through the hole during folding and unfolding. Not ideal, but it is the only way to deal with this issue. External cable routing would eliminate this issue, at the expense of a less tidy cable routing.

After testing this bike for an extended distance of 60+km, it is all ready to go. It is not for my own use, but I build every bike as if it is my own, ensuring that it is adjusted correctly and optimally. Yet another bike project has been completed!