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Chinese Carbon Road Bikes => Road Bike Frames, Wheels & Components => Topic started by: Ryanprun on May 19, 2024, 11:20:22 AM

Title: Ltwoo GR 9 rear brake shifter failure
Post by: Ryanprun on May 19, 2024, 11:20:22 AM

I swapped a flat bar for a drop bar on a gravel bike and installed a GR9 ltwoo system.

Everyone was fine for the first 100 miles or so. Then while braking the rear brake locked up. Now I am unable to bleed it. Ie can not push any fluid through. Any ideas?

 I did like the 11-51 range and it shifted nicely with a Shimano cues cassette.

https://youtu.be/f8Mo6jD_9Mg?si=KxQ43l1xF8FciirY

Title: Re: Ltwoo GR 9 rear brake shifter failure
Post by: Chiyou on May 20, 2024, 02:50:26 PM

If it were me, I'd try to isolate the faulty component as a first step. I can't quite make out what you are saying in the video so ignore this if you've covered these steps already.

First, remove your rear wheel and the brake pads to avoid contamination with mineral oil; next, disconnect the brake hose from the caliper. Then try to move some mineral oil through the caliper with your bleed kit. If you can't, you know the brake is faulty.

If the path internal to the caliper is clear, either the hose is blocked (unlikely) or the hydraulic module within your shifter is borked.

Title: Re: Ltwoo GR 9 rear brake shifter failure
Post by: Ryanprun on May 20, 2024, 04:10:45 PM

Thanks for the reply.
I actually tried a different brake with the same results. Ie unable to bleed so yes I believe something is wrong with the shift lever itself.