Specialized Aethos: Dura-Ace C36 Wheelset and GP5000 Tires

Building a lightweight bike requires a lightweight wheelset. For the Specialized Aethos, I decided to get a relatively lower profile carbon wheelset to help save some weight.

Previously I got the Dura-Ace C50 wheelset for the Focus Paralane, during the change to 12 speeds. That C50 wheelset with a 50 mm tall rim profile weighs 1493 grams, which is a good weight but not really lightweight.

This time, I got the Dura-Ace C36 wheelset, which is exactly the same as the C50 wheelset, except for the lower 36 mm rim profile. Due to the lower profile, the wheelset will be lighter. Check out the details below.

Dura-Ace C36 R9270 wheelset

Dura-Ace wheelsets are available in 36, 50 and 60 mm rim profiles. The C36 is the lightest but also least aerodynamic.

Specialized Aethos: S-Works SL Stem and PRO Vibe Superlight Handlebar

In the earlier posts about the Specialized Aethos, I have shared some information about the frame, fork and other small parts that come with the frameset.

As the Aethos is designed to use a standard stem and handlebar, with no integrated cable routing at the front, it means that I am free to choose a stem and handlebar to use. I like it this way as I am not a fan of integrated cockpits. Although it looks very neat and clean, it takes a lot of effort to assemble this kind of integrated cockpits. If you leave this job to the experienced bike mechanics at the shop, it is not an issue for you. However, if you prefer to work on your own bikes, I would definitely prefer to have a non-integrated front end that I can work on easily.

For a lightweight build, the weight of every part needs to be considered carefully, as every gram counts. I have considered using super lightweight parts from Darimo, but the price is just too high for me to accept, at $750 for a handlebar and $650 for a stem. An alternative is to use Specialized own stem, which is pretty lightweight. It also matches the S-Works frameset which is a nice touch as well.

Specialized S-Works SL Stem, ordered online from the Singapore Specialized store.

I was surprised to see how moldy it is straight out of the box!

Specialized Aethos: Front Brake Caliper Adapter and Disc Rotors

The Specialized Aethos uses mostly standard components and specifications. For example, it uses a standard threaded bottom bracket and round seat post on the frame. There is no internal routing around the head tube and steerer tube of the fork as well.

However, there is one non-standard design on the fork, which is the disc brake mounting area. Although it uses a flat mount brake design, the distance between the holes are not the flat mount standard.

According to Specialized, the holes are closer than the usual flat mount standard, so that they can make the end section of the fork leg hollow, in order to save some weight. Not sure if it is worth it to make this non-standard design, when most other areas are standard.

Flat mount holes on the front fork, where the hole to hole distance is closer than usual.

Special flat mount adapter (top) supplied with the Aethos frameset, and it means only a 160 mm front rotor can be used.

Specialized Aethos: Thru Axles, Roval Seatpost and Di2 Battery

On the Specialized Aethos, there are many high end components used, with the main objective being to make the bike as lightweight as possible.

Starting with the super lightweight sub-600 gram frame and sub-300 gram fork, even the fork expander plug is designed to shave off every gram possible. To continue with this lightweight theme, the other parts on the bike are also designed or chosen to be lightweight.

In the previous posts on the frame and fork, I shared that the thru axles are designed to rest inside a countersunk, giving a seamless look on the outside of the frame. To do so, the thru axles need to have a chamfered head to match, as shown below.

Aethos 142x12 mm rear thru axle, only 29 grams.

Aethos 100x12 mm front thru axle, only 22 grams.

Specialized Aethos: Headset, Spacers and Expander Plug

Joining the Aethos frame to the Aethos fork is the headset and other small parts around the headset. As mentioned earlier in the posts, the Specialized S-Works Aethos uses an integrated headset design, with the bearing races already molded directly into the head tube of the frame, and steerer tube of the fork. This eliminates any extra headset bearing races that needs to be pressed into the frame, such as on the Fnhon Gust or Fnhon Tornado frames.

Headset bearing races already molded into the head tube, at the top and bottom.

The frameset includes the headset bearings, and here are some pictures of it. Good reference for the future when a new replacement bearing needs to be sourced.

Headset top bearing, with 1 1/8" inner diameter and a 45 degree chamfer.

Specialized Aethos: S-Works Fork

Previously, I showed the Aethos frame, which is part of the Specialized S-Works Aethos frameset. Now, let's look at the S-Works Aethos front fork. This fork is included in the frameset, along with the frame and seat post.

Being an S-Works fork, I expect it to be lightweight as well. At this price range, it is a given that the fork has a full carbon steerer tube for minimum weight. 

S-Works Aethos front fork, with a long carbon steerer tube.