Cervelo Aspero: Assembly Completed

Finally the Cervelo Aspero has been completed! It is not easy to build up a bike from scratch, as you need to gather all the parts and components needed, without making any mistakes. After that, it takes quite a bit of work to assemble all the parts correctly. If you had made any mistakes when choosing your components, you will realize it during assembly.

As you already know, this Cervelo Aspero will be used as both a road bike and a gravel bike. It only requires a quick wheelset swap to convert between these two types of bikes.

Let's take a look at the completed bike in both road and gravel configurations. Finally, I will show the Di2 wiring layout for this bike, and also the final component list.

PRO Vibe cockpit, with the PRO Vibe Aero Superlight handlebar and stem.

Another look at the PRO Vibe stem. The carbon headset spacer has an outer diameter that is bigger than the stem, which affects the appearance of the bike.

With the new Bracket Cover on the shifters, and the fresh Lizard Skin bar tape.

Aero handlebar with a flat top area, which is claimed to improve aerodynamics. I like it for the comfortable flat holding surface.

Di2 Junction A, EW-RS910 tucked neatly into the right side of the handlebar drops. Di2 wires run internally inside the handlebar.

The hydraulic hoses and Di2 wire exits from the bottom of the handlebar near the stem. Di2 wire that runs to Junction B is routed together with the rear brake hose.

Rear brake hose and Di2 wire enters the top tube. Front brake hose runs into the left side fork leg.

There is a plastic cable cover that is used to cover up the cable entrance.

Dura-Ace + GRX drivetrain! Shown here is the GRX RD-RX815 and the 11-34T HG800 cassette.

The gravel setup uses the Panaracer GravelKing SK 650B tires that are 43 mm wide.

Here is how the 650B tires look on the Hunt 650B Adventure Carbon Disc wheelset.

About 7 mm of clearance between the tire and the chain stay. Also enough clearance between the 4iiii Precision power meter and the chain stay.

With the SKS Explorer Edge frame bag installed.

Full view of the gravel bike! The wide gravel tires with brown sidewalls look nice on this bike.

No toe overlap when using these gravel tires, which are smaller than standard road tires.

Here is how the road setup looks like! The Teal coloured frameset stands out well from the black components.

The paint job looks fantastic under sunlight, where the glitter can be seen reflecting through the gloss finish.

Did I say I love the paint job?

Three bottle cage bosses for you to choose the position of the water bottle.

The glitter looks really nice under sunlight. Indoor pictures are not able to show how awesome the paint job is.

Glittery paint with light coloured paint splatters makes this frame unique. Plus it hides most of the dirt, so I don't need to clean it so often.

With these standard road tires, there is a bit of toe overlap. Can be avoided if you position your foot correctly during sharp cornering.

Comparison with the Canyon Endurace. The components have been moved over to the Cervelo Aspero.

Handlebar height on the Cervelo Aspero is slightly taller, but the reach is also slightly further forward.

Di2 wiring layout on the Cervelo Aspero. Wiring around the handlebar area is unconventional, but it hides the wireless unit neatly inside the handlebar.

Full component list, with the numbers in red highlighting the main areas where the weight gain comes from, compared to the Canyon Endurace.

The Aspero frame weighs about 370 grams more than the Endurace, while the fork also weighs 50 grams more. Compared to a full Dura-Ace road setup, the GRX RD weighs about 100 grams more than the Dura-Ace RD, while the special BBright bottom bracket also weighs about 90 grams more than Dura-Ace SM-BB92. With a heavier frameset, it is expected that the Cervelo Aspero will weigh more than the Canyon Endurace.

Cervelo Aspero road setup without pedals: 7.6 kg
Canyon Endurace road setup without pedals: 7.0 kg

Cervelo Aspero road setup with pedals: 8.0 kg
Canyon Endurace road setup with pedals: 7.4 kg

Compared to the Canyon Endurace (full Dura-Ace), the Cervelo Aspero weighs about 600 grams more, even with the road setup. About 400 grams comes from the frame + fork + thru axle lever, while the other 200 grams come from the heavier GRX RD and Wheels Manufacturing BBright bottom bracket.

Gravel setup, with the wheelset, tires, brake rotors and cassette switched.

By isolating the weight of the wheelset, the weight difference for the gravel setup can be determined. The table above shows the weight of the gravel wheelset (inclusive of tires, inner tubes, disc rotors, cassette), and it weighs almost 500 grams more than the road wheelset.

Although the Hunt gravel wheelset is 200g lighter than the Reynolds Assault road wheelset, the heavier gravel tires, inner tubes and cassette adds back the weight and more.

Cervelo Aspero gravel setup without pedals: 8.1 kg
Cervelo Aspero gravel setup with pedals: 8.5 kg

In summary, this Cervelo Aspero weighs 8 kg in the road setup, and 8.5 kg in the gravel setup. Not a lightweight bike, but it cannot be helped due to the relatively heavy frameset weight.

Cervelo Aspero: Road vs Gravel Setup

As you already know by now, my Cervelo Aspero is a dual use bike, which means that it can be both a road bike and a gravel bike. This only requires a wheelset swap, as already demonstrated successfully on the Canyon Endurace.

Although the Cervelo Aspero is designed as a fast gravel bike, there is no reason why it cannot be a good road bike as well. All it needs is a fast set of high profile carbon road wheels and smooth rolling road tires. The frame geometry is very similar to that of an endurance road bike, which means it is not too upright for fast rides. Even though the frameset is quite a bit heavier than the Canyon Endurace, it is acceptable as it is not meant to be a pure climbing bike.

The road wheelset is the same old Reynolds Assault Limited Edition Disc wheelset that came stock with the Canyon Endurace, with Continental GP4000 28 mm wide tires. The actual tire width is about 32 mm due to the wide 21 mm internal rim width. This is a good wheelset that I like very much.

On the other hand, the gravel wheelset that I will use on the Aspero is the new Hunt 650B Adventure Carbon Disc wheelset, with 43 mm wide Panaracer GravelKing SK tires. Although the previous DT Swiss G 1800 gravel wheelset was good, it is for 700C tires, which is not what I want on the Aspero. Instead, I want to take maximum advantage of the big tire clearance on the Aspero, which is why I will use 650B wheels and wide tires.

As shown below, the road wheelset and gravel wheelset are different, which means that I do not need to compromise a single wheelset and tire to fit both road and gravel riding. The road wheelset can be optimized for fast road riding, while the gravel wheelset will be optimized for comfort and traction during off-road riding.

650B wheels are visibly smaller than the 700C wheels. The taller 650B tire is not enough to make up for the difference in rim diameter.

Cassette and Rotor Comparison

Road wheels use a Dura-Ace 11-30T cassette and a Dura-Ace RT900 160 mm diameter disc rotor.

Gravel wheels use a HG800 11-34T cassette and a Deore XT RT800 disc rotor, also 160 mm diameter.

Front Wheel Comparison

Road front wheel, with high profile rim and road tires.

Gravel front wheel, with a smaller 650B low profile rim, but high volume gravel tires.

It is necessary to use the same size of disc brake rotors and number of speeds on the cassette, if you plan to swap wheels like this. Remember, the idea is to make it as fuss-free as possible to convert between a road and gravel bike setup, with just a wheelset change. No adjustment should be needed.

On both wheelsets, the rotor is located at almost the same position, and I was able to setup the brake calipers to accommodate that. Therefore, there is no brake rotor rubbing when swapping between these two wheelsets.


Front Fork Tire Clearance Comparison

Lots of tire clearance at the fork around the 700C road bike tire. This frame can accept up to 700Cx42 mm wide tires.

Lots of clearance radially, when using the smaller diameter 650Bx43 mm tire.

Rear Wheel Setup Comparison

Road rear wheel

Road rear wheel with 11-30T cassette, using the GRX rear derailleur.

Gravel rear wheel with 11-34T cassette, also using the same GRX rear derailleur. There is no need to adjust the rear derailleur setting after swapping wheels.

Rear Chain Stay and Seat Stay Clearance Comparison

Still plenty of tire clearance at the seat stay area, around the wide gravel tires. There will be even more clearance when the road tires are used.

Still lots of clearance around the rear road tire, along the seat tube and the chain stays.

For the gravel tire, there is more clearance with the seat tube due to the smaller tire diameter, but lesser clearance with the chain stays as the gravel tire is wider.

In the picture above, notice that the 4iiii power meter on the left side crank arm manages to clear the frame. There is actually a healthy amount of clearance with the left side chain stay. In fact, there is more clearance than on the Canyon Endurace frame (shown below).

Small clearance between the left side chain stay and the power meter, on the Canyon Endurace.

Initially I thought that the left side chain stay is pushed outwards due to the BBright construction. However, later I realized that it is actually the same as the standard press fit BB construction. At the same time, the left side chain stay also needs to be moved outwards to give wider tire clearance. In summary, the Cervelo Aspero can accommodate wide tires, and still have enough clearance for a left crank arm power meter!

Non drive side view of the road setup

Non drive side view of the gravel setup.

Drive side view of the road setup

Drive side view of the gravel setup

As you can see from the pictures, only the wheelset is changed between the road setup and the gravel setup. Visually it looks quite different, especially the tires. However, the drivetrain is almost completely the same, except for the cassette.

Due to the different tire diameter, the clearance between the bottom bracket and the ground is also different. The gravel setup has lesser ground clearance due to the smaller tire diameter.

There is a diameter difference of 16 mm between these two tires. Therefore, the radial difference is 8 mm. This 8 mm will be the difference in axle height from the ground, and also the bottom bracket distance from the ground. Tire deflection under rider's load is not accounted for in this case.

BB to ground distance for Continental GP4000 road tires (700C x 28): 268 mm
BB to ground distance for Panaracer GravelKing SK gravel tires (650B x 43): 260 mm

The ground clearance of 260 mm may seem to be too low, but it does not give me any problems. I don't encounter pedal strikes when leaning over on gravel or on smooth tarmac. This is likely helped by my usage of 165 mm crank arms, which are 5 mm shorter than the more common 170 mm crank arm length.

Cervelo Aspero: Assembly Begins

Prior to this blog post, there have been many other blog posts leading up to this, listing the new parts that will be used to build the Cervelo Aspero. From the frame to the fork, and the miscellaneous parts for the frame, these are studied in detail to document the part design and weight. A new Hunt 650B wheelset and Panaracer GravelKing tires were also prepared, along with the PRO Vibe handlebar and stem, and finally the special BBright bottom bracket by Wheels Manufacturing.

Finally, all the parts are ready and I am able to build up the new Cervelo Aspero from the frameset. Of course, some parts are transferred over from the Canyon Endurace, which means that I also have to disassemble them from the Canyon Endurace first.

While transferring over the Dura-Ace ST-R9170 road hydraulic Di2 shifters, I took the opportunity to replace the rubber bracket covers. I have wanted to replace the bracket covers for some time as they were loose, but replacing it requires removing the shifters from the handlebar, plus disconnecting the hydraulic hoses from the shifters. This means rebleeding the brakes is necessary. It is too much trouble just to replace the bracket covers, which is why I have not done so.

Now, since I have drained the hydraulic fluid when I removed the shifters from the Canyon Endurace, it is the best chance to replace the bracket covers.

Replacement rubber bracket covers for road shifters. Make sure to get the correct model!

The one on the left is obviously used, as it is dirty and well stretched/deformed.

The rubber of the old bracket cover has stretched and does not match well with the bracket of the road shifter.

It was rather difficult to remove and reinstall the bracket covers though. It helps if you put some rubbing alcohol on the surfaces to aid the installation. Be careful not to over-stretch the new bracket covers while installing them.

I forgot to take a picture of the shifters with the new rubber bracket cover, but I was very pleased with the result. It feels like a brand new shifter again! Pictures of the shifters can be seen later during the bike assembly.

Another part which I almost forgot was the rear brake adapter for 160 mm diameter disc rotors. This is not included with the frameset, so you will need to get it separately. More details on the Flat Mount rear brake adapter can be found here, on the Fabike C3. The default rear rotor size will be 140 mm in diameter, if an adapter is not used to install the rear brake caliper.

Flat Mount rear brake adapter, to match with 160 mm diameter rotors.

The brake adapter itself plus the bolts weigh 17 grams.

Full front brake assembly, including the special Flat Mount adapter for rearward positioning of the Trail Mixer on the Aspero.

Full rear brake assembly, including the rear brake adapter. Lots of parts as you can see.

As shown above, the front brake assembly weighs 149 grams, while the rear brake assembly weighs 150 grams. This includes all the small parts needed to mount the brake caliper onto the frame, plus the connecting bolts of the shifter side and brake caliper side. The connecting inserts and olives are not included here.

Before I can route the hydraulic hoses, I need to set up the handlebar first, so that I can install the shifters onto the handlebar. Only then would I be able to measure the hose length from the shifters to the brake calipers.

This means that the fork, stem and handlebar needs to be installed first. As shown previously, the PRO Vibe stem is special as the top of the steerer tube does not need to protrude above the top cap.

With 40 mm of spacers under the stem, the stem position is perfect, and there is no need to cut the steerer tube at this point in time.

Stem, handlebar and road wheelset installed onto the frameset, so that I can start installing the shifters and brakes. Looks like a track bike now!

New Selle Italia SLR Titanium saddle and Cervelo SP19 carbon seat post installed.

The distinctive V-shaped face plate of the PRO Vibe stem can be seen here.

The next step is to thread the Di2 wires and hydraulic hoses through the handlebar, for a clean and integrated look. However, it was the most difficult and frustrating part of the build, even though I used a proper internal routing kit to help route the Di2 wires and hydraulic hose through the handlebar.

This was partly due to my unconventional Di2 wiring layout, as first used on the Dahon MuSP. However, this was made worse by the small holes on the handlebar, which made it very difficult to fit the Di2 wires and hydraulic hose through it. There were also some sharp bends which were nearly impossible to route the Di2 wires through. If I were to choose again, I would not run internal cable and wire routing on the handlebar.

On the right side shifter, 1x hose and 2x Di2 wires pass through the hole on the handlebar. It is a very tight fit.

On the left side shifter, 1x hose and 1x Di2 wire pass through the hole. This is more manageable.

The hydraulic hoses and Di2 wires also run internally through the frame and fork, but that was easy as there is more space to route them properly. Once done, the length of the hydraulic hose will be determined. With the hydraulic hoses connected to the shifters and brake calipers. hydraulic fluid can be used to fill the brake system.

With the brake system completed, the next step would be to install the drivetrain. This is mostly a Dura-Ace groupset with hydraulic brakes and Di2 shifting. The only non Dura-Ace component is the rear derailleur, which has been changed to the GRX RD-RX815 for more chain capacity, to match the larger 34T sprocket on the gravel wheelset, and also for the clutch function.

For setting the chain length, I installed the gravel wheelset, as I need to base the chain length on the larger 34T sprocket which is on the gravel wheelset.

Hunt 650B Adventure Carbon Disc wheelset with the Panaracer GravelKing SK 650B tires.

Trail Mixer on the fork is set to the rearward position for more trail and thus better stability.

2x11 speed drivetrain installed successfully! Lowest gear ratio is 1:1 due to the 34T inner chain ring and 34T large sprocket.

Di2 wire for the front derailleur comes out from the side of the seat tube as shown here.

There is about 7 mm of clearance on each side of the 43 mm wide tire. This corresponds to the claimed maximum space of 57 mm when using 650B tires. (43 + 7 + 7 = 57 mm).

There is very little clearance between the 50T outer chain ring and the chain stay! Probably only 1 mm of clearance. A larger chain ring will not be possible unless the chain line is moved outwards.

View of the gravel front wheel with the nice looking Deore XT RT800 160 mm diameter disc rotor, and the Dura-Ace brake caliper with special brake adapter for the Aspero.

Lots of tire clearance at the sides, and even more in the radial direction. This is no surprise, as my wheel size comparison have shown that this 650B wheel size is quite a bit smaller than normal 700C wheelsets.

Gravel rear wheel with 160 mm diameter disc rotor, and brake adapter for the brake caliper.

Plenty of tire clearance around the seat stays.

The assembly of the Cervelo Aspero is almost completed! There are just a few more small areas that need to be adjusted and finalized. Stay tuned for the next few blog posts!