Fabike C3: Assembly Part 2 - Road Bike Setup

In the previous post, the main components of the Fabike C3, such as the wheelset and the drivetrain were installed. Once that is done, the cockpit area can be set up properly. Let's now take a closer look at the new handlebar setup and also the full bike!

A completely new cockpit setup, with new handlebar, shifters, Di2 display and bar tape.

PRO PLT aluminium handlebar, mounted on the previous Controltech 80mm stem.

With the new Deore XT Di2 display, SC-MT800. Shows the selected gear and also the battery level.

Internal cable routing, for the Di2 wire and also the rear brake hose. The rubber grommet of the rear brake hose does not fit into the hole on the frame when fitted around the brake hose.

Thomson Elite seatpost after cutting to the correct length. Di2 battery is hidden inside this seatpost.

Using the same Dura-Ace 7900 5 arm crankset with the same 46T Gates chainring.

Belt tension adjusted with the eccentric bottom bracket

Alfine 11 Di2 internal hub

With Alfine Di2 motor unit mounted

Top view of the rear hub area and the Gates CDX carbon drive belt, with a length of 113T.

Maintenance-free drivetrain setup. With belt drive and internal hub, there is no chain or derailleur which will rust when used in wet weather.

Front hub with 12mm E-thru axle. The silver coloured DT Swiss front hub looks a bit out of place here when located next to all the other black components.

View of the DT Swiss ER 1600 Spline DB 32mm front wheel, with the Dura-Ace RT900 disc rotors.

Rear wheel with the same 160mm Dura-Ace RT900 disc rotors and non-series RS805 brake calipers.

View of the full bike! Looks and rides just like a normal road bike, which makes this an all-weather commuting road bike!

Other than the belt drive, the other components look the same as on normal road bikes. Also note the bent seat tube to allow a short chain stay and yet sufficient rear tire clearance.

Using the Canyon Endurace road bike as a reference, I tried to make the setup exactly the same on the Fabike C3, so that these two bikes will feel the same when I ride them. Previously, the Avanti Inc 3 commuting bike was more upright with a different geometry, which made it ride differently from the Canyon Endurace road bike.

The gearing is as shown below, which is the same as on the Avanti Inc 3. With a gear inch of 24 to 99, it is a good range that is more than enough for city commuting.

Gear ratios and range of the Fabike C3.

Using the bottom bracket as a datum for the whole bike, I adjusted the saddle position and handlebar position on the Fabike C3 to follow the Canyon Endurace. Basically, set the same distance from the bottom bracket to the saddle, and likewise to the handlebar.

However, after I set up the Fabike C3, I found that the saddle height and handlebar height is actually higher than the Canyon Endurace. Why is this so, even though I used the bottom bracket as a datum? Both the bikes have a distance of 64.5cm from bottom bracket center to the top of the saddle.

Putting the new Fabike C3 next to the Canyon Endurace, the saddle height is different by about 1 cm.

The shifter position on the Fabike C3 is also higher than the Canyon Endurace, by about 1 cm.

Upon checking again, I found that the bottom bracket height is different on these two bikes. On the Canyon Endurace, the distance from the center of the bottom bracket to the ground is about 27.5cm, while the distance on the Fabike C3 is slightly further at 28.5cm.

In other words, due to the eccentric bottom bracket adjustment, the Fabike C3 has a bottom bracket height that is 1 cm higher. As I used this point as the datum, both the saddle and handlebar position will be 1 cm higher, as what I have measured.

Therefore, these two bikes have the same riding geometry, just the the Fabike C3 is raised by 1 cm overall. This was my intention all along when I got this new Fabike C3 frame, which is to have a commuting bike that has the same geometry and riding feel as the Canyon Endurace road bike.

This bike is not quite all-weather yet, as the SKS mudguards have not yet been installed. That will be shown in the next post where all the accessories will be installed on this bike.

Fabike C3: Assembly Part 1 - Component Installation

With all the components gathered, this new Fabike C3 commuting bike is now ready to be assembled! As already shown in the previous posts, there are many new components, such as the front wheel, brakes, handlebar, seat post and etc.

Before installing the components, I want to cut the fork steerer tube to the correct length. This will enable me to fix the handlebar position, which will then allow me to fix the shifter positions. Only when that is done, I can connect the Di2 wires, and also set the correct length for the hydraulic brake hoses.

I wanted this Fabike C3 to have the same geometry as my Canyon Endurace road bike, which is why I measured and used the same setup for the handlebar height, using the bottom bracket as the datum. Once this is done, I can cut the steerer tube to the required length, as it is definitely too long.

Cutting the carbon steerer tube at this blue line. After that, a spacer and top cap will be placed on top of the stem.

With the handlebar position fixed, all the Di2 wires can be connected, and the hydraulic brake hoses can be measured and cut to the required lengths. For this setup, the Junction B will be stored internally, within the down tube.

Wrapping the Junction B in sponge to prevent rattling, before stuffing it inside the down tube. The other bundle is actually the wire from the Di2 battery in the seat tube, which has a Di2 wire that is too long.

After running the Di2 wires internally, I can install the eccentric bottom bracket, followed by the crankset. This Dura-Ace 7900 crankset is the exact same one which I removed from the Avanti Inc 3, and I plugged it straight into this new frame.

However, I noticed that the Gates front chainring was rubbing against the frame, on the right side chainstay! There is insufficient clearance on this frame...

No clearance between the chainring and the frame, on the right side chainstay.

On the previous setup, the chainring was located on the INSIDE of the crankset, in order to match the chain line from the Alfine 11 Di2 internal hub at the rear. However, this is not possible on this frame due to interference.

In this case, I have to place the chainring on the OUTSIDE of the crankset, in order to avoid interference with the chainstay. This causes the chain line to be a little bit offset from the rear sprocket, but hopefully it will be OK.

Switching the chainring placement to the OUTSIDE of the crankset. Looks better in this case.

With the chainring located on the outside, there will be about 2mm of clearance with the chainstay, which is good.

Next, the rear wheel will be installed, and it will involve using the special rear dropout design described earlier.

First, the non turn washers will need to be slotted onto the hub axle. Then, the hub axle needs to be rotated so that the flats on the hub axle matches the opening on the frame.

In this orientation, the non turn washers cannot slot into the dropout. Therefore, the frame needs to be widened by a few millimeters, to allow both the hub axle and the non turn washers to be installed. Check out the pictures below.

Orienting the hub axle to slot it into the frame. Frame needs to be spread open slightly to allow the non turn washers to be slotted in at the same time.

After the hub axle is in place, rotate the hub axle, so that the profile of the non turn washers match the profile on the inside of the frame dropouts. Then, slot the non turn washers into the frame, to close up the frame.

Not sure if you are able to understand or follow the steps, but it is a very troublesome method, as many areas need to be aligned at the same time, for both left and right side of the hub axle. Also, note that I did not install the rear brake caliper yet, as spreading the frame will mean that the brake caliper will move to the side, and possibly bend the brake rotor.

Removing the rear wheel will be similarly tricky, as the non turn washers need to be pushed out from its slot on the frame, followed by rotating the hub axle to come out through the opening in the dropout. If I ever get a rear wheel puncture on this bike, I am not sure if I will bother to fix it at the side of the road, or catch a transport home to fix it later.

Anyway, that is probably the most difficult part of setting up this bike. With that settled, all other issues should not pose a big problem.

New Gates Centertrack 113T belt is needed for this frame, as the chainstay is quite short. I could not reuse the other longer 115T or 118T belts that I already had.

Once the belt is installed, it can be tensioned by rotating the eccentric bottom bracket as shown. One of the rare occasions where this tool is actually used!

Adjustment of this eccentric bottom bracket is not as straightforward as it seems. It is important to make sure that both sides of the eccentric bottom bracket are aligned, to prevent the crankset spindle from being tilted. However, since the adjustment is only done at the left side, it is necessary to make the right side follow the adjustment closely.

This synchronized adjustment is only possible if the 3 bolts on the eccentric bottom bracket are tightened, to minimize the play between the left and right side eccentric bottom bracket. However, if the 3 bolts are too tight, it will be clamped onto the frame and cannot be adjusted. This makes adjustment quite tricky. Once done, the 3 bolts are tightened to clamp both the left and right side to the frame, to fix the position.

As mentioned earlier, the change of front chainring position will cause the chainline to be offset slightly to the side. However, based on my testing, it seems to be OK as the belt is still able to roll on and off the chainring without any problems.

There are some other issues which I noticed during the installation of the components, which I will highlight below. These are not critical issues, but something that can definitely be improved upon by the frame maker.

Slight touching between the Di2 motor unit and the inside of the right side seat stay. Can be solved by changing the angle of the non turn washer, or creating more clearance on the right side seat stay.

Once the hub axle angle is fixed by the non turn washer, the angle of the Di2 wire points downwards by 45 degrees, instead of being horizontal. This is not as neat, and can be solved by changing the angle of the non turn washer.

Rubber grommets at the head tube for Di2 wire and hydraulic brake hose do not fit well. The Di2 wire grommet fits too loosely into the hole on the frame, while the grommet for the brake hose becomes too big, and cannot be fitted into the hole on the frame. Can be solved by sizing the hole and rubber grommet properly.

When the wheels are installed, there is quite a small clearance between the tire and the frame. To be fair, these are 28C tires which come up to 32mm wide on these rims. Hopefully the mudguards will fit in this small gap!

Same for the front, there is small clearance between the tire and the fork. Need to fit the mudguard into the small gap without rubbing the tire.

Mounting point for front mudguard is hidden at the back of the fork, which is neat. Slight peeling off of the paint here, but not a big issue.

More to come in the next post!

Fabike C3: Thomson Elite Seatpost with Internal Di2 Battery

The Fabike C3 frameset does not come with a seat post, so I will need to get a seat post for this bike. It accepts seat posts with a diameter of 31.6mm, so I can actually reuse the Kore seat post that I was using on the Avanti Inc 3.

However, that Kore seat post was rather heavy at about 300 grams for a 400mm length, so I decided to get a new one for the new bike. Carbon seat posts are lightweight, but also quite expensive. I found that actually Thomson aluminium seat posts are also very lightweight, although they are not that cheap. I decided to get a Thomson seat post to try it out, and see how good the seat post is.
.

Very obvious what is inside this cloth bag...

Comes with the manual and also some stickers.

Some detailed instructions and warnings. Apparently seat posts have a useful life of 5 years only...

Angle adjustment is limited to 29 degrees downwards, and 5 degrees upwards.

Diameter 31.6mm, with a length of 367mm.

Internal walls are oval shaped, to preserve material only where it is needed most for stiffness and strength.

Saddle clamp design which is found on many other seat posts such as Litepro seat posts.

Saddle clamps are forged from aluminium, for low weight and high strength. Most other brands use cast aluminium (thicker and heavier) or steel (heavy).

Weighs only 221 grams, for 31.6mm diameter and 367mm length! This is as light as many carbon seat posts of the same specifications.

I was amazed at the low weight of this Thomson seat post, as it is as light as many carbon seat posts, while also being a lot cheaper. Of course, a Thomson seat post still costs more than a standard aluminium seat post, but it is more lightweight. In other words, a Thomson seat post is almost as lightweight as a carbon seat post, but at a price point somewhere in between normal aluminium and carbon seat posts.

For internal Di2 batteries, normally it is fixed inside the seat post, or somewhere on the frame like on the Canyon Endurace. In my case, I have to fix it inside the seat post.

The challenge with putting the battery inside the seat post is to make sure it does not drop out during riding, while making sure that it can be removed if required. With special seat posts from PRO, you can use an E-ring to hold the battery, but for all other seat posts, you have to use a rubber plug to hold the battery.

Rubber plug from Deda, for holding the Di2 internal battery inside the seat post. 

Weighs 20 grams if anyone is interested.

It fits snugly into the end of the seat post, with this part sticking out, so that you can pull it out later.

Weight of Di2 internal battery, at just 52 grams. Slim and long to fit inside the seat post.

The battery goes into the rubber plug, and this whole assembly is then fitted inside the seat post.

However, I found that the battery was slightly loose inside the rubber plug, which is why I wrapped a few layers of black tape around the battery to improve the fitting.

With the battery and rubber plug fitted inside the seat post!

This rubber plug fits the seat post tightly, without being overly tight that I need to use excessive force to push it in. Even swinging the seat post does not cause the battery to fly out, so I think it should be tight enough.

As mentioned earlier, the Fabike C3 frame can only allow a maximum of 120mm of seat post inside the frame. On the other hand, we need to maintain a minimum insertion length of 100mm inside the frame. Therefore, the seat post will need to be cut to the correct length, to meet my height requirements, and at the same time, 100-120mm of insertion length.

After some calculations and trial and error, I finally settled on the ideal seat post length. It will be 250mm in total, with 100-120mm inserted inside the frame. This means cutting the excess length off from this Thomson seat post.

Length that was cut off is about 167mm, which reduces the seat post weight by 44 grams.

The final specifications of this seat post is thus 250mm in length, with a weight of 177 grams. This is very lightweight, which is really nice as it is not even a carbon seat post. In the future, if I ever need to get a new seat post, I will definitely consider a Thomson aluminium seat post as it is lightweight, strong and yet still cheaper than a carbon seat post.

Fizik rubber seat post ring, to be used to close the gap between the seat post and the saddle clamp, to prevent water flowing in.

With all the components settled, it is time to assemble everything onto the Fabike C3 frameset!