L-Twoo eRX Road Electronic Hydraulic Disc Brake Groupset

If you’re in the market for a wireless groupset for your road bike then the L-Twoo eRX system has plenty going for it: it’s compatible with a range of cassettes, it’s reasonably light, and it works well. You’re certainly getting a lot for your money, although the system isn’t without its niggles.

> Buy now: L-Twoo eRX Road Electronic Hydraulic Disc Brake Groupset for c£540 from AliExpress

The eRX system I’ve been using is a bare-bones groupset: shifters, front and rear derailleurs and brakes, along with the associated hoses and wiring. You don’t get a chain, cassette or crankset, but that’s by design – this groupset is designed to work with any cassette from 10 to 12 speed, so you can use it with a wide range of different components. Because the rear mech is motor-driven it doesn’t have a pull ratio; instead you have a stepper motor moving the cage, and by adjusting the number of steps you can accommodate different sprocket spacings.

I don’t have a 10-speed bike in the shed but I’ve fitted this groupset to 11- and 12-speed bikes (SRAM 12 speed and Shimano 11 speed) and it works with both.

L-Twoo eRX: Setting up

You adjust the parameters of this groupset via L-Twoo’s app. The app is an integral part of the system, and it’s okay – it has all the functionality you need to set up and tweak the setup. And tweak it you will: the app has a standard setup for different cassette spacings but I found that there’s a fair bit of messing about needed to get it working smoothly.

The app is actually quite powerful; once you’ve selected the number of sprockets you’re running you can go into each individual one and adjust the shifting, to get it running smoothly. It’s definitely worth spending a half-hour at the outset getting everything running just so in the workstand before you head out.

I had more success with getting the shifting right when I was running it as an 11-speed transmission, and got to the point where I was happy with the shifts across the whole cassette. Setting up as a 12-speed system was more fiddly; the gaps between the sprockets are only marginally smaller, but the eRX rear mech just didn’t seem to cope quite as well. It was fine – I fitted it to my Lauf Úthald and rode a 200km audax with no real issues – but it never felt like it was quite dialled in, even when it was running perfectly in the stand.

The front mech was easier to set up. For the first ride as an 11-speed setup I just couldn’t seem to get it right out on the road, but after some fiddling in the shed I reached a point where it was working well. It was easier with the 12-speed bike, funnily enough.

The main take home is that there’s some fiddling to be done, but if you’re having issues with a particular gear you can address it mid-ride using the app.

L-Twoo eRX: Shifting

The shifters use a similar layout to Shimano, with two paddles behind the brake lever to shift up and down. In the app you can choose which controller does which mech but you can’t change to a SRAM-style shift setup or assign the buttons individually.

The lever itself is carbon, which is very good spec considering the price, and it helps to keep the weight down. My groupset tipped the scales at 1,267g, which is comparable with Shimano 105 (1,222g claimed for the same components) and SRAM Rival (1,297g).

Like both of those groupsets, the eRX uses wireless shifters powered by a coin cell battery, and like Shimano it wires both mechs through the frame to a single battery which fits inside the seatpost; you’ll need holes for the wires to fit it.

The wires themselves are a four-pin design with a connector that’s a little bulkier than Di2, and they’re a push fit rather than a positive click, but they’re easy enough to connect up.

The battery itself is almost identical in size to Di2 but the capacity is a fair bit higher, at 800mAh compared with 500mAh for Shimano. You charge the system via a USB-C port on the front derailleur. It’s well sealed with a rubber cover, but it’s also on the back of the mech so it’s going to get a lot of spray from your rear wheel in the rain, so make sure the bung is properly in. I’ve ridden plenty in wet weather with this groupset, though, and I’ve not encountered any issues at all.

The fact there’s an easy-to-access charge port means it would be pretty simple to charge out on the road, assuming you’ve got a battery pack: just plug it in at the cafe stop. A full charge takes a couple of hours, but you could easily put enough in to get you home.

L-Twoo eRX: Braking

The brakes are a standard single-piston design fitted with heatsink pads that (I think) would be interchangeable with Shimano pads – they’re the same size, anyway. The system uses mineral oil and the bleed port is on the top of the lever, along with an air port which the bleed instructions say you shouldn’t need to touch. They use the same kind of olive/barb arrangement as Shimano brakes, and a Shimano bleed kit fits to the callipers and levers.

Okay, bleeding. This was a real low point of the system for me. Bleeding a Shimano disc brake is enormously straightforward, and although bleeding a SRAM brake has a few more steps it’s not exactly hard. But getting these brakes bled and biting nicely was a bit of a nightmare.

I fitted them to two bikes, and each time I had issues pushing oil through the system. There’s a 2mm lever adjustment screw on the front of the lever that also pre-loads the piston so you can adjust the bite, and Youtuber Jourdain Coleman found that having that screwed in too far blocked the line and prevented bleeding, but I don’t think that was my issue.

I suspect there was some kind of airlock, because I did eventually manage to get both brakes bled without adjusting that screw, through a combination of bleeding, and trying to release air from the second port on top of the lever, and re-fitting the olives and barbs, and swearing.

Once you’ve got the system bled you can screw that pre-load screw in to adjust the bite point; don’t screw it too far, though, or it’ll fall out and you’ll have to take the whole lever apart to refit it.

Anyway, assuming you do finally get the brakes bled and biting to your satisfaction, they’re fine. I’d say the feel of the system is more Shimano than it is SRAM, and there’s plenty of power available.

The heatsink pads should dissipate heat so brake fade shouldn’t be too much of an issue; I could get a single brake to fade by dragging it down a long hill, but it was no worse in this regard than other single-piston callipers and there was never a moment in normal riding where I ever felt that braking was compromised. The stock pads were a little squeaky in the wet, but again, no worse than the usual suspects.

The levers are a nice shape for my (big) hands and everything felt like it was in the right place. The rubber cover is a harder grade than you’ll find on levers from the big manufacturers, and as a result it’s not quite as comfortable, or as grippy. I don’t normally wear gloves, so I probably noticed this more than most, but even so it wasn’t really an issue.

The hoods are at least nice and hardwearing, so they’ve survived two bike fits and a couple of thousand kilometres outdoors and still look box-fresh.

L-Twoo eRX: Value & conclusion

Let’s talk value. Right now if you’re buying the eRX groupset the chances are you’re going to be getting it from AliExpress (it’s not on Amazon at the moment), and it’s going to cost you somewhere south of £600 if you shop around on there. In theory that’s a fraction of the price of SRAM Rival AXS or Shimano 105 Di2, but the market reality at the moment is that both of those groupsets are fairly heavily discounted: the newest SRAM Rival full groupset can be had for about £1,200 and Shimano 105 is available at under half price, which means it’s less than £900. And both of those prices are for full groupsets – with eRX the cranks, chain and cassette are going to cost you extra.

If you’re building up a new bike right now then it’s pretty hard to look past 105 Di2 given how good it is; when Stu reviewed it he only really marked it down on price and the lack of a power meter option, and price is not a barrier right now.

That may not be why you’re looking at eRX, though. Maybe you’ve got a bike with mechanical shifting, or mechanical disc brakes, or both, and you want to upgrade to posher gears and brakes. The L-Twoo kit is more compelling because it only replaces the bits you really need to, and it’ll work with what you’re currently running. Given the price and the functionality it’s definitely worth a look if that’s your circumstance, although I’d factor in some swear time for the brake bleeding and gear tweaking.

My only other worry would be the warranty: buying anything direct from a long way away is going to be a headache if any bit of it goes wrong. I had an issue with one of my control wires, which was a fairly easy fix in terms of getting a new one, but if your shifter or your mech fails then dealing with that could be problematic.

Overall, it’s a cautious thumbs-up. Once it’s fitted and fettled the system works well, but I think there is work to be done here, and it would be nice if it was available directly from a European distributor.

> Buy now: L-Twoo eRX Road Electronic Hydraulic Disc Brake Groupset for c£540 from AliExpress

Verdict

Wireless groupset upgrade that’ll work with 10-12-speed cassettes, but a pain to fit

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