Hi all,
I’m building my first road bike and I’m stuck with a bottom bracket issue.
Setup
- Frame: Evolve Cima (BSA 68 mm shell)
- Crank / PM: Magene TEO (29 mm / DUB spindle)
- Bottom bracket: Black Bearing BSA-68/73 DUB ceramic
- Disc brakes, Di2
- No chain installed
Problem
After installing the BB and crank, the crank spins only about 1–2 turns and then stops hard. It doesn’t coast smoothly.
At first I had a wave washer installed on the crank side (my mistake). After removing it, the crank spins a bit more but still only ~2 turns before stopping.
What I’ve checked / done
- Wave washer removed
- No obvious frame or crank arm contact
- BB cups torqued correctly
- Crank preload only set to remove play (not over-tightened)
- Same behavior with no chain and wheel out
- Video of the issue here: 👉 [PASTE YOUR VIDEO LINK HERE – Imgur / YouTube]
From the feel, it seems like the bearings are braking themselves rather than normal friction.
Question
Does this look like:
- Damaged ceramic bearings from axial preload?
- Spacer / shell width issue with BSA 68 + DUB?
- A known issue with some DUB threaded BBs?
Before I replace the BB, I’d like a sanity check from people who’ve seen this before.
Thanks a lot 🙏
Crank spins ~2 turns then stops – DUB BB issue? (video included)
byu/Ok_Customer1600 inbikewrench
by Ok_Customer1600
10 Comments
something of a similar observation from another post that may quell your concerns: https://www.reddit.com/r/bikewrench/s/w7Iv3RUA7f
Looks fairly normal for most BBs I’ve worked with. Those videos of endless spinning look cool on Instagram but most are probably not preloaded correctly.
Edit: To expand, does it feel smooth? Like, if you spin the crank at a constant speed, does it feel smooth throughout the cycle? Are there any tight spots? Does it feel crunchy? Does it feel like it’s catching on something?
Looks normal to me. Does it take any noticeable amount of force to start it moving?
Try backing the preload off a tiny bit more if you’re concerned.
I think as long as the bearing don’t rotate with a sound or cause vibrations feel able throughout the frame, then it’s not an issue.
That resistance is absolutely negligible while riding. It’ll probably break in over time
Zero resistance to spinning would mean zero seal contact and zero protective grease. So a time bomb maintenance nightmare. Not worth it
Takes a bit for the new grease to wear in. If it feels smooth, you’re good.
I’ve had this happen on new cranks and a used t47 bb. Issue for me was the bearings in the bb shell weren’t fully seated. Pressed them in more and it fixed it.
Not normal. The bottom bracket spacer is on the wrong side or is dragging. You will feel this while riding. I would re-do the cranks. Double check the manual so the spacer is in the right place for your BB.
Don’t get tricked by the clips you see of people spinning their cranks and they spin forever. That isn’t really how it goes for most, and that is fine. Bearings come packed with grease new, especially some brands. Over a matter of a few rides, they ‘break in’ which just means smooth out and loosen the grease.