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!