Chinertown
Chinese Carbon MTB => Metal Frames => Topic started by: tiWannaB on April 20, 2026, 04:15:17 AM
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Hi all,
Posting here to get some advise on my Ti frame with a BB thread issue.
As you can see in https://drive.google.com/file/d/1tVSjN4kgdVVZhmxKV1atiwVq9r1Y-2hP/view?usp=drivesdk (https://drive.google.com/file/d/1tVSjN4kgdVVZhmxKV1atiwVq9r1Y-2hP/view?usp=drivesdk), the T47 bottom bracket is very loose.
I’ve tried two different SRAM T47 BBs and one from Shimano, they all have the same excessive play. In my experience, these should be a much snugger fit.
The second half of the video shows us attempting to tighten it to spec with a torque wrench. It "slips" in the threads, and immediately afterward, I can unscrew the cup with my bare fingers. It’s clear that the internal threading of the frame is out of tolerance. Strange thing it that sometimes it will torque but I don't think I can trust this. I don't want to be out riding and it comes loose.
I am in contact with the manufacture, and they’ve proposed making a "custom part" to resolve this. I’m struggling to see how a custom part fixes a stripped/worn or oversized internal thread.
If they provide a custom "fix," I won’t be able to use standard, off-the-shelf T47 bottom brackets in the future. I’ll be dependent on this manufacturer for replacements.
I paid for a new, functional frame, not one that requires a "hack" to meet basic standards.
I received the frame in December but due to travel and work, I didn't start the build until late March. Because I’m outside the first-month window, they are pushing the repair over a replacement. I had a cycling trip planned with this bike for this month (April) that is now not possible and I don't know when I will be able to eventually ride this bike. It's been going on for about 4 weeks already.
Since the frame is 3D printed, the BB shell can’t simply be cut out and replaced like a traditional Ti frame.
What would you do in this situation? Should I push for a full frame replacement (if at all even possible) despite the time elapsed, or is there a legitimate "custom part" fix for T47 shells that I’m not aware of?
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Looks like something went wrong when they machined the BB thread.
If they provide you with an BB with the right thread, you still can change bearings when they're worn out and leave the BB shell in the frame.
But I totally understand that this is not an satisfactory solution.
Which company made the frame? Old PM me if you don't want to share publicly.
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I don't think there is any real solution here except to return the frame. You cannot convert this frame to a press fit as t47 is a PF30 with threads cut into it.
This is a warranty issue, if they have one, and I guess a lesson to the rest of us to test-fit parts right away.
I wouldn't accept the fix either, as you are on the hook for a custom part down the line if it fails, and while the factory might be able to knock one out today, it will cost you quite a bit more if you need a replacement, as one-off CNC work is typically pretty expensive.
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They have agreed to a new frame, unfortunately I need to pay for the shipping, which is NOT cheap at all. I still feel this is not fair, seeing I paid to get a working good frame!
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Shipping is probably around 300 EUR.
@ tiWannaB, so who is the seller?