Author Topic: LTWOO RX hydro sets  (Read 32033 times)

jonathanf2

Re: LTWOO RX hydro sets
« Reply #120 on: April 10, 2023, 08:57:25 PM »
Finally got the 1x11 GR9 installed, but I think I have a faulty shifter. Can’t get the indexing right and it seems to miss shifts.

Did you pull the cable tightly all the way through the shift cable housing? That can sometimes cause laggy indexing from the shifters.

00Garza

Re: LTWOO RX hydro sets
« Reply #121 on: April 10, 2023, 09:26:43 PM »
Did you pull the cable tightly all the way through the shift cable housing? That can sometimes cause laggy indexing from the shifters.

Disclaimer: I have a local bike mechanic working on it for me.

He tried with with a shimano shifter and rear mech worked perfectly. So it’s definitely something shifter wise. He’s going to be taking a look under the hood (pun intended) to see if there’s a simple solution tomorrow morning.

jonathanf2

Re: LTWOO RX hydro sets
« Reply #122 on: April 10, 2023, 10:36:00 PM »
Disclaimer: I have a local bike mechanic working on it for me.

He tried with with a shimano shifter and rear mech worked perfectly. So it’s definitely something shifter wise. He’s going to be taking a look under the hood (pun intended) to see if there’s a simple solution tomorrow morning.

I just checked my uninstalled hydraulic 2x R9 shifters and they are ridiculously stiff. There's a possibility the shift cable might be jammed on your GR9 shifter. I think it's a good idea to actuate the shift lever a few times through the 11/12 speed range before installing to loosen the mechanism. I'm really surprised just how stiff it feels as well. I have the original mechanical (non-hydraulic) GR9 shifters, and the shift lever has a very light mechanical touch similar to Shimano.

cestmoi

Re: LTWOO RX hydro sets
« Reply #123 on: April 11, 2023, 01:52:29 AM »
Isn't it possible to slacken the shifting tension by an adjuster bolt? I'm sure Trace Velo pointed that out on YT.

mirphak

Re: LTWOO RX hydro sets
« Reply #124 on: April 11, 2023, 10:31:46 AM »
1) check that the cable is routed correctly, mine was not.
2) there is a screw, if I remember correctly it is on the side of the clamp / the one that faces the handlebar, to adjust the tightness. Maybe yours is too loose / tight.

jonathanf2

Re: LTWOO RX hydro sets
« Reply #125 on: April 11, 2023, 12:26:20 PM »
Isn't it possible to slacken the shifting tension by an adjuster bolt? I'm sure Trace Velo pointed that out on YT.

I found the screw and adjusted mine, still feels clanky versus clicky compared to the non-hydraulic LTwoo shifters. I'm beginning to think I should just sell my LTwoo hydraulic shifters. I'm actually pretty happy with my current Juin Tech F1 brake setup with 105 shifters for road.

00Garza

Re: LTWOO RX hydro sets
« Reply #126 on: April 11, 2023, 01:42:17 PM »
I found the screw and adjusted mine, still feels clanky versus clicky compared to the non-hydraulic LTwoo shifters. I'm beginning to think I should just sell my LTwoo hydraulic shifters. I'm actually pretty happy with my current Juin Tech F1 brake setup with 105 shifters for road.

Could you show me a pic of the screw?
Lots of folks seem happy with theirs. Worst case scenario, I might just have a dud on my hands. Best case scenario, it was routed poorly from factory and needs a little extra work. Fingers crossed.

s3si1u

Re: LTWOO RX hydro sets
« Reply #127 on: April 11, 2023, 01:50:24 PM »
I found the screw and adjusted mine, still feels clanky versus clicky compared to the non-hydraulic LTwoo shifters. I'm beginning to think I should just sell my LTwoo hydraulic shifters. I'm actually pretty happy with my current Juin Tech F1 brake setup with 105 shifters for road.

 :D Was just thinking of buying some for my gravel bike as I'm not totally happy with my current setup...
No pressure but do let me know if you decide to sell  ;D

jonathanf2

Re: LTWOO RX hydro sets
« Reply #128 on: April 11, 2023, 05:59:38 PM »
:D Was just thinking of buying some for my gravel bike as I'm not totally happy with my current setup...
No pressure but do let me know if you decide to sell  ;D

I'll think about it. Part of me is just lazy to bleed the brakes, hence why I haven't done the install yet!  ;D

dsveddy

Re: LTWOO RX hydro sets
« Reply #129 on: April 11, 2023, 10:10:31 PM »
I'll think about it. Part of me is just lazy to bleed the brakes, hence why I haven't done the install yet!  ;D

So this might sound like a bodge, but I actually have gotten away with bleeding using just the cone at the top. None of this syringe bleeding business that is demonstrated in the videos. I have gotten effective bleeds just by hooking everything up, putting a bleed cone at the top with oil, and squeezing the brakes a few times until the bubbles stop coming out. It takes a couple of sessions to get to 100% bled, but you get completely usable brakes after the first session, and then the few bubbles trapped in the caliper come up after a couple of shakedown rides. SUPER easy.

coffeebreak

Re: LTWOO RX hydro sets
« Reply #130 on: April 11, 2023, 11:49:31 PM »
I have gotten effective bleeds just by hooking everything up, putting a bleed cone at the top with oil, and squeezing the brakes a few times until the bubbles stop coming out. It takes a couple of sessions to get to 100% bled, but you get completely usable brakes after the first session, and then the few bubbles trapped in the caliper come up after a couple of shakedown rides. SUPER easy.

This is the way. To corroborate, I was struggling with MTB style brakes for quite some time. Started with super budget Tektros, then to TRP Slate and finally to Shimano XT. After bleeding each of these for may be 6-7 times back to back, I couldn’t get the bite that I wanted. Just mushy mess. And then finally this tutorial helped - a technique called bubble bleed:

https://m.pinkbike.com/news/tech-spotlight-5-minute-bubble-bleed-2014.html

5 minutes and voila, my brakes feel so good. Don’t forget to take the lever off of handlebar and tap them with a rubber mallet. And of course the bleed port at the highest position possible. Then rotate the lever without spilling the oil (if there is oil in the cup). This was the only way I could get that last holdout air from the reservoir. When it worked I almost felt silly.

jonathanf2

Re: LTWOO RX hydro sets
« Reply #131 on: April 12, 2023, 10:33:34 AM »
So this might sound like a bodge, but I actually have gotten away with bleeding using just the cone at the top. None of this syringe bleeding business that is demonstrated in the videos. I have gotten effective bleeds just by hooking everything up, putting a bleed cone at the top with oil, and squeezing the brakes a few times until the bubbles stop coming out. It takes a couple of sessions to get to 100% bled, but you get completely usable brakes after the first session, and then the few bubbles trapped in the caliper come up after a couple of shakedown rides. SUPER easy.

I've used this method to get rid of excess air bubbles, but never for the full bleed. I'll definitely give it a try.

TidyDinosaur

Re: LTWOO RX hydro sets
« Reply #132 on: April 12, 2023, 10:47:09 AM »
I tried to bleed /fill my GRX brakes this way,but since the brifters were not pre-filled this did not work. It didn't matter how long I kept trying. Only the syringe on the caliper worked.

kbernstein

Re: LTWOO RX hydro sets
« Reply #133 on: April 12, 2023, 02:48:53 PM »
So this might sound like a bodge, but I actually have gotten away with bleeding using just the cone at the top. None of this syringe bleeding business that is demonstrated in the videos. I have gotten effective bleeds just by hooking everything up, putting a bleed cone at the top with oil, and squeezing the brakes a few times until the bubbles stop coming out. It takes a couple of sessions to get to 100% bled, but you get completely usable brakes after the first session, and then the few bubbles trapped in the caliper come up after a couple of shakedown rides. SUPER easy.

You don't even open the bleed nut on the caliper? Is this suitable when you might need to top up some oil? You just open the shifter bleed port, screw the funnel, put some mineral oil and squeeze for a while?
I'm probably going to do my first bleed next week on my new build and every video is different. GCN and RoJ's seem the easiest/most intuitive

dsveddy

Re: LTWOO RX hydro sets
« Reply #134 on: April 13, 2023, 11:12:40 PM »
You don't even open the bleed nut on the caliper? Is this suitable when you might need to top up some oil? You just open the shifter bleed port, screw the funnel, put some mineral oil and squeeze for a while?
I'm probably going to do my first bleed next week on my new build and every video is different. GCN and RoJ's seem the easiest/most intuitive

Nope, just open the oil port on the brifter, cone on with oil, squeeze lever. As I see it, putting the syringe at the bottom is primarily for flushing old fluid out, which is important since mineral oil dissolves water. But for the the bleed itself, syringe comes out, caliper gets sealed back up, and I just squeeze the lever with the cone on top.

For topping up oil, I suggest putting on the cone with oil and squeezing the levers once or twice with no bleed block in place. The LTWOO hydro systems are known to have issues getting full volume in the first place, leading to too much lever throw. This is the protocol LTWOO recommended to the China Cycling YT channel to address the issue.