LTWOO RX hydro sets

[Sebastian]

I've done a teardown of my broken LTWOO brifter to see what's inside. I have the part-1 video up right now on youtube. Interesting finds include that the hydraulic reservoir is a modular part that pops right out.

(What's inside a L-TWOO hydraulic lever? Teardown & anatomy of a failure)


I'm currently putting together a video demoing the rebuild and analyzing/explaining the shift mechanism (hopefully dropping this week), but the short of it is that the shift mechanism is pretty much identical in design to Campy Ultrashift (diagram attached). This is a bad thing IMO. Fundamentally, this is a friction shifter. To hold the cable in place, it uses a friction plate with indexing indents pushed up against the de-tensioning ratchet by a couple of spring washers. You adjust the friction with the screw in the back of the shifter. Shifting feels tough because you have to overcome the friction plate in addition to everything else. I also think it's not suitable for off-road use, where a bump can increase the tension on the cable and spontaneously advance the index, causing a mis-shift

It's more or less an exact copy of Campagnolo's Hydro Shifters internally. Having worked on the Campy shifters, I can say that even the modular hydro unit looks identical maybe except for a few minor details. I've been running Ultra Shift in many iterations and it has gotten better every time. The 12sp generation has super light and smooth action. If you can shift it comfortably in the drops very much depends on bar shape and hand size. I have no problem shifting these in the drops.
I've also never had issues with riding these offroad. Campy has been used by quite a few pros in CX back in the rim brake days. With all that said, I dunno what level of quality the LTWOO internals are. Copying stuff is one thing. Doing it well is another.

[raisinberry777]

I've done a teardown of my broken LTWOO brifter to see what's inside. I have the part-1 video up right now on youtube. Interesting finds include that the hydraulic reservoir is a modular part that pops right out.

(What's inside a L-TWOO hydraulic lever? Teardown & anatomy of a failure)

Appreciate the detailed teardown. That was an interesting look at their levers. Seems like it's worth waiting for some more fixes to be put in place.

[dsveddy]

It's more or less an exact copy of Campagnolo's Hydro Shifters internally. Having worked on the Campy shifters, I can say that even the modular hydro unit looks identical maybe except for a few minor details. I've been running Ultra Shift in many iterations and it has gotten better every time. The 12sp generation has super light and smooth action. If you can shift it comfortably in the drops very much depends on bar shape and hand size. I have no problem shifting these in the drops.
I've also never had issues with riding these offroad. Campy has been used by quite a few pros in CX back in the rim brake days. With all that said, I dunno what level of quality the LTWOO internals are. Copying stuff is one thing. Doing it well is another.

Thanks for the feedback! I have never worked hands-on with Campy so I've only been able to go off of the material online, which admittedly is sparse, it's good to hear from someone with real-life experience on this.

I guess I'm still on the fence over if this is a "good" indexing design. On one hand (as you illustrate) Campy has a good track record with making it work well, even in off-road applications. On the other hand this friction system design is inherently a zero-sum compromise between shift-action-lightness and indexing security. Meanwhile, Shimano and SRAM's systems use mechanical interference to achieve indexing.

[00Garza]

I've done a teardown of my broken LTWOO brifter to see what's inside. I have the part-1 video up right now on youtube. Interesting finds include that the hydraulic reservoir is a modular part that pops right out.

(What's inside a L-TWOO hydraulic lever? Teardown & anatomy of a failure)


I'm currently putting together a video demoing the rebuild and analyzing/explaining the shift mechanism (hopefully dropping this week), but the short of it is that the shift mechanism is pretty much identical in design to Campy Ultrashift (diagram attached). This is a bad thing IMO. Fundamentally, this is a friction shifter. To hold the cable in place, it uses a friction plate with indexing indents pushed up against the de-tensioning ratchet by a couple of spring washers. You adjust the friction with the screw in the back of the shifter. Shifting feels tough because you have to overcome the friction plate in addition to everything else. I also think it's not suitable for off-road use, where a bump can increase the tension on the cable and spontaneously advance the index, causing a mis-shift

Great teardown. Really insightful. I was a campy fan on my road bike, so I'm hopeful for how my GR9 will do longterm.

Also, did Pepper get any pets?! You left us hanging lol!

[raisinberry777]

Thanks for the feedback! I have never worked hands-on with Campy so I've only been able to go off of the material online, which admittedly is sparse, it's good to hear from someone with real-life experience on this.

I guess I'm still on the fence over if this is a "good" indexing design. On one hand (as you illustrate) Campy has a good track record with making it work well, even in off-road applications. On the other hand this friction system design is inherently a zero-sum compromise between shift-action-lightness and indexing security. Meanwhile, Shimano and SRAM's systems use mechanical interference to achieve indexing.

As far as off-road goes, it's worth noting that for Ekar, Campagnolo changed the thumb lever design a bit (L-TWOO's version is almost like a hybrid between the Ekar version and the original Ultrashift version) and it's a single-click only. I don't think this is a bad thing - over the years I've had 9/10 speed Campagnolo Chorus (with the multi-shift down) and 11 speed Potenza (single shift down, with the droopy thumb lever)

For reference - ultrashift levers (note higher thumb button):


Powershift levers (see lower thumb button):


Ekar levers (redesigned thumb button):


For what it's worth, I think the single-click Powershift levers with the lower thumb button are excellent - the improved ergonomics is worth the trade-off against being able to shift across multiple harder gears. I have found that on bumpy surfaces, the Ultrashift levers can sometimes have me going down two gears when I only intended to go down one. I suspect that's why Campagnolo may have taken that approach with Ekar.

[Sebastian]

Thanks for the feedback! I have never worked hands-on with Campy so I've only been able to go off of the material online, which admittedly is sparse, it's good to hear from someone with real-life experience on this.

I guess I'm still on the fence over if this is a "good" indexing design. On one hand (as you illustrate) Campy has a good track record with making it work well, even in off-road applications. On the other hand this friction system design is inherently a zero-sum compromise between shift-action-lightness and indexing security. Meanwhile, Shimano and SRAM's systems use mechanical interference to achieve indexing.

I'm totally with you. I don't think the Ultra Shift mechanism is well suited to off-road use. You can occasionally overshift the thumb paddle when going over rough terrain. And I do think that's why Campy used their Power Shift mechanism on their gravel group Ekar. I'm using both and they each have their strenghts and weaknesses. I'm currently building up a Velobuild VB099 with LTWOO RX12 speed for a friend. I'm very curious to compare it with my Record 12sp groupset and see if I can get it to shift just as smoothly. I will report back.

[mirphak]

Maybe I am the outlier here, but I have ridden my ltwoo RX since basically the moment they came out (I believe I got them in december of so !).

At first I was not very enthusiastic about the braking and the shifting. Braking was ok, better than in the hybrid sensah shifters I had before, but a bit worse than in the shimano GRX. Shifting was so-so in the small ring, and pretty awful in the big ring. Installation was not straightforward.

First, one of my levers did not have the cable routed correctly (see https://www.youtube.com/shorts/_vF6lKv7aeE ).
Second ... the pulleys that came with the rear derrailleur are too narrow and basically garbage. Do yourself a favor and replace them with some stone narrow-wide pulleys (11t/12t and 14t work fine).

Over time, however, the shifting has gone consistently better, to the point that right now it is just flawless. It is silently, it basically never misshifts. Only sometimes I need to help it to index when downshifting, but this is 100% my fault because I wrapped two layers of bar tape and the hood got pretty thick at the base rubbing a bit the side-lever. Not that annoying in any case, so not in a hurry to fix it.

The braking stayed more or less the same. Okeish, but I would have preferred a more aggressive braking with less dead-zone and shorter reach. I found out that the pistons tend to open a bit with time, so from time to time (maybe once every month or two) to recover the harder feel I like, I put some rubber holding the brakes actuated over night so that the pistons close a bit by themselves. The next morning they are pretty good.

I am indeed tempted by the electronic groupset, but what holds me back are the reports about the water tightness (the 80 designer store person told me they are sorted out, but I honestly don't believe so without proof), the autosleep, the removal of auto-trim  and the fact that the derrailleur probably has the same rather-weak spring as the mechanical one. I wish it had a stronger spring and I wish there was a 1x version of it with a clutch.

[frnchy]

Update to my previous post. I built up the bike and have gotten a bit of time in on it - not enough for any real judgements but enough for first impressions.

Build notes:

• The brake bleeding process is exactly as depicted in the official bleed guide video on youtube. I used the same EZmtb brake bleed kit that Trace Velo used, which has the adapter needed to screw into the caliper. The brake lines and brifter bodies came filled with light blue oil, which I flushed out and replaced with shimano mineral oil. Really easy bleed, no more difficult than any of the shimano brakes I've done. I did unscrew the free throw adjustment screw before bleeding; after the bleed was done the brakes were firm but needed to be pulled back quite far to make contact with the rotor, and screwing in the free throw screw about 3 turns reduced the throw a lot while not negatively affecting rotor/pad clearance as far as I could tell (no rubbing).
• I used a housing ferrule with a plastic sheath to protect from the sharp edge on the cable exit of the rear derailleur as depicted in tsneidin's post previously. The shift indexing is VERY sensitive to cable tension; a quarter turn of the barrel adjuster yields very noticeable differences in shift performance.
• The b adjustment screw on the rear derailleur is almost useless. I'm using a 46 tooth cassette and have the b screw backed out almost all the way.
• The clutch isn't as strong as the ones on Deore or GRX rear derailleurs, but still seems adequate for a 1x setup. It's certainly stronger than the first gen Sensah SRX clutch which dropped my chain quite a few times.

Some impressions from the brief amount of time I've put on this groupset:

• The brifters are quite petite. I have average sized hands and if the brifters were any smaller I wouldn't be able to get my entire palm on the top of the hoods. The shape is quite nice though, and there's support in the brifter body everywhere there's contact with the hand or fingers; overall quite comfortable.
• The braking is excellent, easily on par with the 105 disc brakes on my other bikes. I haven't experienced any rattling from the brake piston retaining clip either.
• The force required to downshift is greater than upshifting, and I often have to use 2 fingers to comfortably downshift. The downshift lever/paddle has a moderately thin section near its top and I'll be keeping an eye on that section for any signs of fatigue.
• The ability to dump 3 gears up + 4 gears down is amazing, I use it quite a lot when slowing down/speeding up or cresting a hill. Probably my favorite feature to be honest. It is hard to dump all 4 gears with the thumb shifter from the top of the hoods, much easier to do in the drops, but I can get 3 gears reliably which is enough for me.
• I'm temporarily using flared bars (~16 degrees of flare) until the actual bars I ordered arrive. The brifters are ok at an angle but I think they'll be more comfortable in a level, non-flared position. Something to think about when choosing bars, as this is nominally a gravel groupset and all gravel bikes seem to come with flared bars these days...
• The compression nuts on the brake calipers seem to be anodized so I don't think they'll be susceptible to the corrosion problems that Trace Velo had. I do live in a much drier environment, but I plan on riding this bike quite a bit in the winter so it is a concern.

I probably won't update again until I've put a lot of miles on this setup, or until an issue arises. I got this groupset hoping it would be a fairly cheap, moderately high-performance, reliable groupset for my commuter/all-around bike, and it seems like it'll fulfill that role admirably.

Photo of the bike, with fit not yet dialed in:

[Bigal]

Are the thumb change levers replaceable I have the earlier style unable to reach from the drops would be better to have the newer ones without replacing the whole unit

[00Garza]

Are the thumb change levers replaceable I have the earlier style unable to reach from the drops would be better to have the newer ones without replacing the whole unit

I highly doubt that they're interchangeable.

[jcr]

With the latest issue on the e-RX/e-R9, it has made me second thought and if I should stick with non-electronic. Just wondering any more long term update or reviews on the RX (thinking of aluminum version). Internally routing it through a frame and bar would probably still be a pain compared going with electronic...

[Sebastian]

I've recently built a V-BR099 with LTWOO RX12.

I was most impressed by the shifters and brakes. The quality is really impressive for the money. The brakes work fine. Everything is super straightforward. Bleeding was easy (once you realize that you need to back off the little reach adjust grub screw in the lever completely in order for the master cylinder to go into the zero position and not block the oil flow).
I like that the FD has its own cable stop and cable tension adjustment mechanism. That makes a lot of sense particularly for fully internally routed frames. You can just run the housing all the way to the FD and adjust the cable tension there. No need for stupid cable stop designs in the frame.

I was least impressed by the RD. The whole thing looks just a bit cheap. The derailleur cage is made of carbon on the outside (which honestly seems to be more for looks than for stiffness) while the inside is made of some sort of polymer (which arrived slightly bent and I had to bend it back into shape - the seller promised to send a spare derailleur cage).
The cable routing is just borderline stupid. Like other people have said already, the cable has to make a super tight turn from the barrel adjuster to where it is clamped down on the RD parallelogram. Therefore, it severely rubs agains the RD housing. I used some liner between barrel adjuster and the clamping screw to alleviate the problem. But still, it's just a very bad design.
It shifts fine. Not stellar but fine.
I wasn't able to get it noise free in the stand. Paired with a ZTTO 11-34 12sp cassette, there was always a clicky gear on either end of the cassette. Curiously though, on the road when shifting under load it is not an issue. So that's fine, I guess.

Lastly, the brifters are obviously Campagnolo copies internally. I'm running the original 12sp Campagnolo Record on my rim brake Velobuild VB-R218 which uses the same kind of mechanism (Campagnolo Ultra Shift). I can say that the LTWOO thumb paddle requires significantly more force and is harder to shift accurately and not overshift compared to Campag. Time will tell if with further use the action gets easier.
Campag are more or less producing this tech ever since their first ergopower 8sp shifters came out so I guess they had 30+ years to perfect it.

For the money, I think it's a great groupset but IMO especially the RD can be improved. If the cable pull ratio is identical, I'd probably put a 12sp 105 derailleur on there and be done with it.

[michael_pappas]

Is there a consensus on what the pull ratio is and if it's compatible with other RDs?

[jonathanf2]

Is there a consensus on what the pull ratio is and if it's compatible with other RDs?

LTwoo rear shifters definitely work with current Shimano 10/11/12 speed which share the same pull ratio (Tiagra 4700, GRX 400/800, 105, Ultegra, etc.)

[dsveddy]

Is there a consensus on what the pull ratio is and if it's compatible with other RDs?

I’ve successfully paired the R9 (11s) with an 11s ultegra rear derailleur