LTWOO eRX Groupset: Front and Rear Derailleurs

Continuing from the previous post, where I showed the shifters and brake calipers of the LTWOO eRX groupset, here are the rest of the components.

Front derailleur is 140 grams, quite a bit more than 111 grams of the Ultegra Di2 front derailleur.

Similar linkage design as Shimano Di2 front derailleurs

Inner view, looks the same as Shimano Di2 front derailleurs.

I find that the corners of the motor housing look quite sharp, perhaps they can be rounded off a bit more.

LTWOO eRX 12 speed rear derailleur. Looks pretty good!

Also uses a similar link design as Shimano Shadow rear derailleurs.

Looks very much like Shimano Di2 rear derailleurs

Here is the port for connecting the electric wire. There is a little notch in the connector to ensure alignment.

Limit screws located at the bottom, both stop against the inner link.

Resin moulded Plate Member with visible fibres in the material, and covered with a clear coat.

Looks like a carbon outer plate on the cage?

Inside view, showing the relatively long cage with an aluminium inner plate.

Weighs 289 grams, a bit more than the Ultegra R8170 version. Can't complain given the price difference.

Other than the components, the groupset also includes the electronic parts required to link up everything. This LTWOO eRX system is semi-wireless, similar to Shimano. The shifters communicate wirelessly with the rear derailleur, while the battery powers both the front and rear derailleurs via wires.

Battery, charging cable, and two electric wires.

Charging cable which has a proprietary connector to the rear derailleur charging port, and is powered by a standard USB port.

Two ports available at the bottom of the battery, to be connected to the front and rear derailleur.

Two electric wires of 90 cm and 120 cm, for the front and rear derailleurs.

I did not assemble the LTWOO eRX groupset on any of my bikes, as I did not think it was better than the Ultegra Di2 groupset that I already have. After this study, I sold the groupset as I had no more use for it.

LTWOO eRX Groupset: Shifters and Brakes

Nowadays, most mid and high end road bikes are equipped with hydraulic brakes as well as electronic shifting. The most common component brands are Shimano with Di2, and SRAM with AXS. Campagnolo has EPS, but it is rarely found because it is so expensive.

There are a few brands which are trying to carve out a slice of the market share for themselves, and one of them is LTWOO. They have been making flat handlebar mechanical shifters for a few years, and now they have decided to release a groupset with electronic shifting and hydraulic braking. This is quite impressive as there are many technical challenges with this kind of system.

As always, I'm curious and decided to order a set for myself to check it out.

LTWOO eRX groupset, with all the components inside this big box.

Nice packaging! Using recyclable pulp tray as well, unlike SRAM's rear derailleur or cassette packaging.

This LTWOO groupset is not a complete groupset, as it does not include the crankset, cassette or chain. It is designed as a 2x12 speed groupset, so you need to find your own 12 speed crankset, cassette and chain. 

One side of the shifter weighs 224 grams, which is heavier than Shimano Ultegra R8170 at 192 grams per side.

The Dura-Ace R9270 shifters are even lighter at 176 grams. Different price point though.

Shifters have a tall hood, and a design very similar to the Campagnolo Ekar shifters.

Connecting bolt already fixed onto the shifter.

The ergonomics of the shifters are very important, as you will be holding on to it nearly all the time. It has to be comfortable to hold, feel secure, and allow you to operate the brakes and shifting easily.

Let's compare the LTWOO eRX shifter with the Shimano Dura-Ace R9270 shifter side by side.

LTWOO shifter has an outline that is similar to Campagnolo and SRAM shifters. However, it has 2 separate shifting buttons like Shimano.

LTWOO shifter has a kinked brake lever to offset the finger contact point outwards, while the Dura-Ace/Ultegra shifters use a 10 degree tilt instead. The hole on the LTWOO brake lever is for reach adjustment.

LTWOO rubber hood has a texture that is similar to SRAM. The difference in shape and size does not look like much, but you can feel the difference when gripping the shifters.

Rear view, with the hose connection located at a similar place.

Comparing the two shift buttons on the brake lever.

Shimano brake lever is almost entirely straight, and also has bigger shift buttons.

This partial groupset also comes with hydraulic brake calipers, let's see if it has anything special.

These brake calipers look to be of the Post Mount type, and not Flat Mount.

The groupset includes some adapters, which are confusing, as they look different from what I usually see.

Luckily I managed to find the assembly manual which makes everything clearer.

The brake calipers look like Post Mount, but they are not. They are neither Flat Mount nor Post Mount! The hole to hole pitch is 70 mm, which is Flat Mount, but you can't mount them directly onto the fork. In the manual above you can see that an adapter is required regardless of rotor size.

Starting with the front caliper, you will need either the 140 or 160 mm adapter, to mount these LTWOO brake calipers to a Flat Mount fork. It is unique because you need to mount the front brake caliper to the Flat Mount of the fork, using a Post Mount style of adapter and bolts. This is completely different to how Shimano Flat Mount is done, where the bolts are threaded into the brake caliper itself.

As for the rear, it looks like a combination of Post Mount and Flat Mount. The brake caliper has to be mounted to the adapter, Post Mount style. Then, the brake caliper + adapter is assembled to the bike using Flat Mount style.

Lots of long and short bolts are provided to cater for different rotor sizes, adapters, and frame dimensions.

Unique brake pad design, with those curved fins.

Plain rear side, nothing to see here.

Do you like this style of brake pad fins? I wonder about the compatibility to other brake pads.

Front caliper with hose and hydraulic oil weighs 167 grams. A bit heavy as it does not include the adapter yet.

Weight of rear brake caliper with hydraulic oil, without adapters.

There is a small insert at the end of the hydraulic hose, which allows you to use an inner cable cast head to pull the hose through during internal routing. Same as what I saw on the Campagnolo Ekar.

Includes its own Connecting Inserts and Olives, as well as Connecting Bolts. Not sure whether the olives are similar to those from another brand though.

Mineral oil is included!

The LTWOO eRX shifters look OK to me, but the brake calipers are a bit weird due to the adapter design. In the next post, let's take a look at the front and rear derailleurs.

Brake Rotor Comparison: CL900 vs MT900 vs RT900

Quick comparison of 3 different top tier Shimano disc brake rotors!

Dura-Ace RT900 - 1st Gen road specific rotor

Large cooling fins help to reduce temperature, and prevent a finger from sticking inside, during a time where people were still wary of the danger of a rotating disc rotor.

XTR MT900 - MTB style rotor, with multiple generations of the Ice Tech design

Latest off-road style rotor, with small cooling fins. Can be used for road bikes too.

Dura-Ace CL900 - 2nd Gen road specific rotor

Cooling fins reduced in size to save weight. Design has been refined to be cleaner, while the spider arms have been redesigned to minimize warpage.

CL900 on left vs MT900 on right. Many people used the MT900 on road bikes as well as it is lighter than the RT900 version, while CL900 was not yet available.

Close up comparison. The CL900 has regular cutouts, while MT900 has more random looking cutouts. Aluminium spider arms on the CL900 is curved as compared to straight on MT900.

CL900 vs RT900. Size of cooling fins have been greatly reduced from the first generation.

Cleaner and slimmer looking CL900 rotor on the left. Circumferential cutouts are larger as well.

Rear side of the CL900 aluminium spider has been reshaped to minimize warpage when heated up. Guess it saves a bit of weight as well.

Comparison of the rivet design.

All 3 different rotors side by side. I choose rotors based mainly on appearance and weight, since they are all cross-compatible.

All weights shown below are for the 160 mm rotor, without the lock ring. Add 7 grams for the aluminium lock ring.

MT900 is the lightest at just 106 grams

Despite being the newest, the CL900 is still slightly heavier at 112 grams.

RT900 has largely been discontinued, as it is heavier at 116 grams. 

It is replaced by MT900 and CL900.

Which is your preferred disc brake rotor? They each have their own distinctive appearance, while the performance should be nearly the same.