Hi, I assembled my bike recently and I noticed that my bottom bracket was not fully threaded in on the drive side. The same amount of space is threaded in the bottom bracket shell as you can see on the pictures. Is it a problem to ride it like this? I’ve taken my bike out a few times already just want to be sure. Thank
CargoPile1314 on
How are 1.) the chainline and 2.) crankarm centering?
twohubs on
That’s an Italian threaded BB shell. It’s right hand drive side threads. The drive side shell is not prepped correctly. Your pedaling forward is causing the bearing to reverse the bearing and shell backwards to unthread the bb. Needs Loctite on the drive side treads. Both shells are drifting since they both turn the same directions and will probably continue to drift out the drive side. Would remove and reinstall with thread prep compound to prevent it from moving again.
Hagenaar on
No bueno. The flange should sit tight aganst the shell. There’s a good chance this will loosen over time.
I would fix this. This sometimes happens when BBs are installed in the wrong order. The drive side should always be tightened first, then non drive side until snug against the cartridge.
To remedy:
Pull cranks,
Loosen non drive side a couple of turns,
Tighten drive side firmly to close the gap,
Tighten non drive cup.
Different-Reporter63 on
A phil wood BB might look like that, I think, to achieve proper chainline.
5 Comments
Hi, I assembled my bike recently and I noticed that my bottom bracket was not fully threaded in on the drive side. The same amount of space is threaded in the bottom bracket shell as you can see on the pictures. Is it a problem to ride it like this? I’ve taken my bike out a few times already just want to be sure. Thank
How are 1.) the chainline and 2.) crankarm centering?
That’s an Italian threaded BB shell. It’s right hand drive side threads. The drive side shell is not prepped correctly. Your pedaling forward is causing the bearing to reverse the bearing and shell backwards to unthread the bb. Needs Loctite on the drive side treads. Both shells are drifting since they both turn the same directions and will probably continue to drift out the drive side. Would remove and reinstall with thread prep compound to prevent it from moving again.
No bueno. The flange should sit tight aganst the shell. There’s a good chance this will loosen over time.
I would fix this. This sometimes happens when BBs are installed in the wrong order. The drive side should always be tightened first, then non drive side until snug against the cartridge.
To remedy:
Pull cranks,
Loosen non drive side a couple of turns,
Tighten drive side firmly to close the gap,
Tighten non drive cup.
A phil wood BB might look like that, I think, to achieve proper chainline.