Continental Terra Speed Gravel Tires

On the Polygon Bend R5 gravel bike, the 1x13 speed Campagnolo Ekar groupset will be installed, along with a new wheelset. The stock wheelset is a 650b wheelset, while the new Fulcrum Rapid Red 300 wheelset is a 700c wheelset. In this case, the stock WTB Venture 47 tires in 650b size cannot be used as it is a different size.

This gives me the freedom to choose a brand new set of 700c gravel tires. As the Bend R5 frame can fit a 650x47 mm wide tire, I was very confident that it can also fit a 700x40c gravel tire. This is from my previous experience on the Cervelo Aspero, where I used both 700c and 650b wheelsets.

I have heard many good reviews of the Continental Terra Speed gravel tires, which is why I decided to try it myself. It is claimed to roll well on tarmac, yet has a knobbly pattern that grips well on loose dry gravel.

Continental Terra Speed TR, which stands for Tubeless Ready.

Campagnolo Ekar: Fulcrum Rapid Red 300 Wheelset

The original intention was to use the existing wheelset from the Polygon Bend R5 gravel bike, but I realized that the Campagnolo Ekar 13 speed cassette requires the new N3W freehub body. There are very few wheelsets that has the N3W freehub body, as this Campagnolo Ekar gravel groupset is still new.

Therefore, the only way to make this work is to get a new wheelset with a N3W freehub body. This is available from Fulcrum, which is a sub-brand of Campagnolo.

This is the Fulcrum Rapid Red 300 wheelset, for 700C tires.

Campagnolo Ekar: Bottom Bracket and Chain

As shown in the previous post about the Campagnolo Ekar crankset, the unique construction means that it will only be compatible to a Campagnolo bottom bracket. These are one of the many unique features of this Campagnolo Ekar gravel groupset.

A Campagnolo bottom bracket is needed to match the Ekar crankset. A standard BSA threaded bottom bracket is chosen to match the bike frame.

At first glance this bottom bracket looks the same as other outboard bottom brackets.

Campagnolo Ekar: Crankset

Next component on the list is the Campagnolo Ekar crankset. Initially I thought of using another crankset, but I realized that I might have a problem finding a suitable chain ring. Due to the unique 13 speed chain which is extra narrow, a special chain ring is needed. Obviously the Ekar crankset and chain ring will fit, but third party options are limited.

During my research, it was not clear if there are suitable third party chain rings that will fit the Ekar 13 speed chain. In order to avoid any potential compatibility issue, I decided to use the Ekar crankset and chain ring to ensure 100% compatibility.

Campagnolo Ekar crankset designed for the 1x13 speed Ekar drivetrain. This set has 170 mm crank arm length and a 38T chain ring.

I would have preferred a smaller 36T or 34T chain ring to match the 9-42T cassette, but it is not available. In this case, a 38T chain ring with the 9-42T cassette on a 700C gravel wheelset gives a gear range of about 25" to 118", which is quite high for gravel riding.

Another unique Campagnolo design, with the spindle split into two halves.

Campagnolo Ekar: 13 Speed 9-42T Cassette

Here comes the highlight of this Campagnolo Ekar 13 speed gravel groupset! In my opinion, the cassette is the most outstanding component of this groupset. Not only is it well engineered, it is also beautifully designed. See for yourself with the pictures below!

Simple packaging, with the small sprockets tucked into the corner.

Campagnolo Ekar: Rear Derailleur

Next component of the Campagnolo Ekar would be the rear derailleur. As it is a 13 speed drivetrain, the rear derailleur needs to be very well constructed and robust in order to achieve good shifting performance across all 13 gears.

In the previous posts, the Ekar shifters, brake calipers and rotors were introduced. Other components will be introduced subsequently.

13 speed rear derailleur, unique to Campagnolo Ekar

Unboxing begins

Overall view of the Campagnolo Ekar 13 speed rear derailleur, with an all black appearance.

Campagnolo Ekar: Brake Calipers and Rotors

The Campagnolo Ekar is a gravel specific groupset, which means that it comes with hydraulic disc brakes. In the previous post, the Ekar shifters were introduced. In this post, I will share more details on the Ekar hydraulic brake calipers and disc rotor.

These brake calipers come as a set with the shifters, with the hydraulic oil already inside the shifters, hose and brake caliper. Theoretically, if you connect everything up properly, there is no need to bleed the hydraulic system. The concept is the same as the Shimano J-kit, but the execution method is different.

On the Shimano J-kit system, the hose is connected to the brake caliper, while on this Campagnolo Ekar system, the hose is connected to the shifters.

Campagnolo Ekar hydraulic brake caliper for Flat Mount, looks good to me! The yellow plug is to keep the hydraulic oil in.

Campagnolo Ekar: Shifters

The Campagnolo Ekar shifters is one of the few gravel specific shifters available in the market. The only other gravel specific shifters that I know of are the Shimano GRX RX815 (Di2) which I am using on the Cervelo Aspero, and the GRX RX810/600/400 mechanical road shifters.

This shifter is unique because it is a 13 speed shifter, with a front single setup. In other words, there is a shifting mechanism for 13 speeds in the right shifter, and no shifting mechanism at all in the left shifter. Both shifters use hydraulic braking for maximum braking performance.

Let's take a closer look, and compare it to the Shimano 105 R7020 mechanical shifter (which is similar to the GRX mechanical road shifters).

Shifters come with the hydraulic brake calipers as a set.

Simple packaging, but looks cheap for a Ekar grade groupset.

XTR Pedals: M9100 Race vs M9120 Trail

Here is another comparison post, where I will compare different XTR SPD pedals. Previously, I had compared two different generations of XTR Trail pedals, PD-M9020 vs the newer PD-M9120. This time, I will compare two pedals from the same generation, but of different types.

There are two types of XTR SPD pedals, the Race type and the Trail type. The main difference is the presence of a pedal cage around the SPD mechanism on the Trail type pedal. From what I understand, the pedal cage is to help support the shoe and the foot in case the rider did not clip in successfully, or if the rider is using a non-SPD shoe for short or casual riding.

On the Specialized Aethos, I installed the Race type XTR PD-M9100 SPD pedal, which is a minimalist SPD pedal with no pedal cage. With that information available, I can do a detailed comparison between the Race type (PD-M9100) and the Trail type (PD-M9120).

XTR level packaging! The Trail pedal needs a bigger box due to the larger pedal size.

Trail PD-M9120 vs Race PD-M9100. Make sure you get the correct type for your usage.

PD-M9120 Trail pedals on the left, PD-M9100 Race pedals on the right.

SRAM Rival eTap AXS Road Shifter and Brake Caliper

For those who have not used SRAM road components before, here is a brief introduction. At the very top level, there is SRAM Red, followed by Force and then Rival. All 3 of these groupsets already have full wireless shifting, with no wires required anywhere.

Each of the shifters has its own coin battery, while the front and rear derailleur has a battery attached to each of them. Although it is a bit more troublesome to charge or replace many different batteries, it is super easy to setup. I liked how easy it was for me to setup the SRAM Force AXS rear derailleur and SRAM GX AXS shifter on the Fnhon DB12 folding bike.

I recently had the chance to study the SRAM Rival eTAP AXS road shifters and hydraulic brake caliper close up. Check out the detailed photos below to learn more about it!

The Rival shifters and brakes (right side only) comes in a HUGE box!