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BB coming loose?!

jonKranked

Detective Dookie
Nov 10, 2005
70,683
13,266
media blackout
Negative ghostrider.
correct. BSA bottom brackets are threaded such that pedaling would loosen them if anything, but correctly torqueing it would prevent this. in the event it does somehow loosen, the fixed width of the crank spacing (spindle) will prevent them from backing out excessively.

non-drive side bb cups tighten normally (clockwise), drive side bb cups are reverse threaded and tighten anti-clockwise.
 

canadmos

Cake Tease
May 29, 2011
13,920
11,100
Canaderp
some questions.....

how old is your frame?

how many different bb's have you gone through on it?

how often do you pull your BB for cleaning/service?

are you using the spacer sleeve with the BB?

have you tried another set of cranks with the bb?
1. Frame is 3 or 4 years old. Most excellent condition.
2. 4 bottom brackets. Two Race Face/Easton bottom brackets with absolutely no issue, even after they became gritty and needed to be replaced. I'm on the 2nd Cane Creek bracket.
3. I've pulled these two Cane Creek bottom brackets probably 6-8 times to either tighten or check them since last fall (haven't ridden this bike since last year).
4. Always.
5. No. If I do that I'm tossing these and getting Shimano cranks.

in the event it does somehow loosen, the fixed width of the crank spacing (spindle) will prevent them from backing out excessively.
The first time this happened, the BB backed out enough that the cranks had noticeable drag while pedaling. I could backpedal a little to loosen them, but eventually I had to walk out.
 

jonKranked

Detective Dookie
Nov 10, 2005
70,683
13,266
media blackout
1. Frame is 3 or 4 years old. Most excellent condition.
2. 4 bottom brackets. Two Race Face/Easton bottom brackets with absolutely no issue, even after they became gritty and needed to be replaced. I'm on the 2nd Cane Creek bracket.
3. I've pulled these two Cane Creek bottom brackets probably 6-8 times to either tighten or check them since last fall (haven't ridden this bike since last year).
4. Always.
5. No. If I do that I'm tossing these and getting Shimano cranks.



The first time this happened, the BB backed out enough that the cranks had noticeable drag while pedaling. I could backpedal a little to loosen them, but eventually I had to walk out.
got it. have you tried an extra bb spacer? if your driveline is good, toss it on the non-drive side.
 

canadmos

Cake Tease
May 29, 2011
13,920
11,100
Canaderp
got it. have you tried an extra bb spacer? if your driveline is good, toss it on the non-drive side.
See that is what I find odd, the non-drive side has no spacer and has not loosened like the drive side one has been doing.

I was thinking, perhaps with less thread engagement on the drive side (due to the spacer and ISCG bracket) and the super finicky bearing that binds if you look at it wrong, maybe its just the perfect recipe for it to occur?

I might try moving the spacer to the non-drive side, so that there is more thread engagement on the drive side - I'll have to keep an eye on the chain line.

I don't think the preload adjuster on the crank can take up enough of the slack with no spacers installed.
 

jonKranked

Detective Dookie
Nov 10, 2005
70,683
13,266
media blackout
See that is what I find odd, the non-drive side has no spacer and has not loosened like the drive side one has been doing.

I was thinking, perhaps with less thread engagement on the drive side (due to the spacer and ISCG bracket) and the super finicky bearing that binds if you look at it wrong, maybe its just the perfect recipe for it to occur?

I might try moving the spacer to the non-drive side, so that there is more thread engagement on the drive side - I'll have to keep an eye on the chain line.

I don't think the preload adjuster on the crank can take up enough of the slack with no spacers installed.
check the frame manual..... the thickness of the ISCG mount may be intended to act in place of the spacer?
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
9,058
5,895
See that is what I find odd, the non-drive side has no spacer and has not loosened like the drive side one has been doing.

I was thinking, perhaps with less thread engagement on the drive side (due to the spacer and ISCG bracket) and the super finicky bearing that binds if you look at it wrong, maybe its just the perfect recipe for it to occur?

I might try moving the spacer to the non-drive side, so that there is more thread engagement on the drive side - I'll have to keep an eye on the chain line.

I don't think the preload adjuster on the crank can take up enough of the slack with no spacers installed.
Have you considered thoroughly cleaning the threads and trying some blue threadlocker?
 

canadmos

Cake Tease
May 29, 2011
13,920
11,100
Canaderp
Have you considered thoroughly cleaning the threads and trying some blue threadlocker?
Yes I have, but I thought threadlocker on aluminum-aluminum was a no-no or increases the chances that it'll get stuck and you'll round it out trying to remove it?
 

Westy

the teste
Nov 22, 2002
44,747
10,396
Sleazattle
See that is what I find odd, the non-drive side has no spacer and has not loosened like the drive side one has been doing.

I was thinking, perhaps with less thread engagement on the drive side (due to the spacer and ISCG bracket) and the super finicky bearing that binds if you look at it wrong, maybe its just the perfect recipe for it to occur?

I might try moving the spacer to the non-drive side, so that there is more thread engagement on the drive side - I'll have to keep an eye on the chain line.

I don't think the preload adjuster on the crank can take up enough of the slack with no spacers installed.

My theory is that since the bearing is cantilevered beyond the threads and with a forward rotating cyclical load, it is getting walked out of the threads slowly. This action could be aggravated if your BB threads are oversized or worn.

If you thread the bearing into place without the spacer, but only as deep as it would be with the spacer, do you get any side to side motion or is everything nice and tight?
 

canadmos

Cake Tease
May 29, 2011
13,920
11,100
Canaderp
My theory is that since the bearing is cantilevered beyond the threads and with a forward rotating cyclical load, it is getting walked out of the threads slowly. This action could be aggravated if your BB threads are oversized or worn.

If you thread the bearing into place without the spacer, but only as deep as it would be with the spacer, do you get any side to side motion or is everything nice and tight?
That makes sense, will check that out.
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
9,058
5,895
After owning more than 5 BB tools, and still don't have one that will work with my DUB BB. I have also resorted to the universal BB tool, pipe wrench.
Maybe ISIS crank pullers and BB cup tools can be re-purposed into zombie bashers for the coming apocalypse?
 

HardtailHack

used an iron once
Jan 20, 2009
3,156
904
Have you checked that your BB shell is circular? Just because it is a threaded BB in as new condition doesn't mean it is a perfectly round. Telescoping bore gauges are pretty handy if a vernier can't get a decent measurement due to lack of access.

I check any new frame's BB shells and HTs just coz I'm a bit weird, worst one was 0.7mm ovality.
 
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canadmos

Cake Tease
May 29, 2011
13,920
11,100
Canaderp
Well in good news, this bottom bracket hasn't come loose again. Opted for no grease and a dab of loctite.


In other Cane Creek bearing news, I put in some Hellbender bearings in the headset last fall. They've been slowly creaking and cracking more and more. CC is sending two new ones to me.

One of them clicks repeatedly if I turn the bars back and forth. And while I'm riding it creaks all the time.

What I find interesting is that apparently these bearings only have a one year warranty, despite their cost.

But the 110 series headset comes with a lifetime warranty, including the bearings. They are the same bearings...whats up with the trickery?
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
9,058
5,895
Hmm, I should check if it's the bearing which occasionally clicks on my hardtail, I think it's 110 top and bottom.